Refactors main function and enhances test suite

Refactors the main function for improved testability by extracting the core logic into a new run function. Updates argument handling and error reporting to use return codes instead of os.Exit. Adds comprehensive test coverage for main functionality, including integration tests and validation against edge cases. Enhances README with updated code coverage and feature improvement lists. Addresses improved maintainability and testability of the application. Bumps version to 0.3.1
Updates version and improves diagram styling
2026-01-16 13:42:10 +01:00 · 2025-05-28 14:23:56 +02:00 · 2025-05-28 13:26:33 +02:00 · 2025-05-28 13:23:45 +02:00 · 2025-05-28 13:17:08 +02:00 · 2025-05-28 13:00:27 +02:00
24 changed files with 6333 additions and 211 deletions
--- a/.github/workflows/autofix.yml
+++ b/.github/workflows/autofix.yml
@ -0,0 +1,25 @@
+name: autofix.ci
+on:
+  pull_request:
+  push:
+    branches: [ "master" ]
+permissions:
+  contents: read
+
+jobs:
+  autofix:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version-file: 'go.mod'
+
+      # goimports works like gofmt, but also fixes imports.
+      # see https://pkg.go.dev/golang.org/x/tools/cmd/goimports
+      - run: go install golang.org/x/tools/cmd/goimports@latest
+      - run: goimports -w .
+      # of course we can also do just this instead:
+      # - run: gofmt -w .
+
+      - uses: autofix-ci/action@551dded8c6cc8a1054039c8bc0b8b48c51dfc6ef
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@ -16,7 +16,11 @@ jobs:
      contents: write
    strategy:
      matrix:
-        go: [1.21.x, 1.22.x, 1.23.x, 1.24.x]
+        go:
+          - 1.21.x
+          - 1.22.x
+          - 1.23.x
+          - 1.24.x

    steps:
      - uses: actions/checkout@v4
@ -37,20 +41,171 @@ jobs:
      - name: Build
        run: go build -v ./...

-      - name: Run tests
-        run: go test -v -race -coverprofile=coverage.out ./...
+      - name: Run tests with enhanced reporting
+        id: test
+        run: |
+          echo "## 🔧 Test Environment" >> $GITHUB_STEP_SUMMARY
+          echo "- **Go Version:** ${{ matrix.go }}" >> $GITHUB_STEP_SUMMARY
+          echo "- **OS:** ubuntu-latest" >> $GITHUB_STEP_SUMMARY
+          echo "- **Timestamp:** $(date -u)" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          
+          echo "Running tests with coverage..."
+          go test -v -race -coverprofile=coverage.out ./... 2>&1 | tee test-output.log
+          
+          # Extract test results for summary
+          TEST_STATUS=$?
+          TOTAL_TESTS=$(grep -c "=== RUN" test-output.log || echo "0")
+          PASSED_TESTS=$(grep -c "--- PASS:" test-output.log || echo "0")
+          FAILED_TESTS=$(grep -c "--- FAIL:" test-output.log || echo "0")
+          SKIPPED_TESTS=$(grep -c "--- SKIP:" test-output.log || echo "0")
+          
+          # Generate test summary
+          echo "## 🧪 Test Results (Go ${{ matrix.go }})" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "| Metric | Value |" >> $GITHUB_STEP_SUMMARY
+          echo "|--------|-------|" >> $GITHUB_STEP_SUMMARY
+          echo "| Total Tests | $TOTAL_TESTS |" >> $GITHUB_STEP_SUMMARY
+          echo "| Passed | ✅ $PASSED_TESTS |" >> $GITHUB_STEP_SUMMARY
+          echo "| Failed | ❌ $FAILED_TESTS |" >> $GITHUB_STEP_SUMMARY
+          echo "| Skipped | ⏭️ $SKIPPED_TESTS |" >> $GITHUB_STEP_SUMMARY
+          echo "| Status | $([ $TEST_STATUS -eq 0 ] && echo "✅ PASSED" || echo "❌ FAILED") |" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          
+          # Add package breakdown
+          echo "### 📦 Package Test Results" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "| Package | Status |" >> $GITHUB_STEP_SUMMARY
+          echo "|---------|--------|" >> $GITHUB_STEP_SUMMARY
+          
+          # Extract package results
+          grep "^ok\|^FAIL" test-output.log | while read line; do
+            if [[ $line == ok* ]]; then
+              pkg=$(echo $line | awk '{print $2}')
+              echo "| $pkg | ✅ PASS |" >> $GITHUB_STEP_SUMMARY
+            elif [[ $line == FAIL* ]]; then
+              pkg=$(echo $line | awk '{print $2}')
+              echo "| $pkg | ❌ FAIL |" >> $GITHUB_STEP_SUMMARY
+            fi
+          done
+          
+          echo "" >> $GITHUB_STEP_SUMMARY
+          
+          # Add detailed results if tests failed
+          if [ $TEST_STATUS -ne 0 ]; then
+            echo "### ❌ Failed Tests Details" >> $GITHUB_STEP_SUMMARY
+            echo "" >> $GITHUB_STEP_SUMMARY
+            echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+            grep -A 10 "--- FAIL:" test-output.log | head -100 >> $GITHUB_STEP_SUMMARY
+            echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+            echo "" >> $GITHUB_STEP_SUMMARY
+          fi
+          
+          # Set outputs for other steps
+          echo "test-status=$TEST_STATUS" >> $GITHUB_OUTPUT
+          echo "total-tests=$TOTAL_TESTS" >> $GITHUB_OUTPUT
+          echo "passed-tests=$PASSED_TESTS" >> $GITHUB_OUTPUT
+          echo "failed-tests=$FAILED_TESTS" >> $GITHUB_OUTPUT
+          
+          # Exit with the original test status
+          exit $TEST_STATUS
+
+      - name: Generate coverage report
+        if: always()
+        run: |
+          if [ -f coverage.out ]; then
+            go tool cover -html=coverage.out -o coverage.html
+            COVERAGE=$(go tool cover -func=coverage.out | grep total | awk '{print $3}')
+            
+            echo "## 📊 Code Coverage (Go ${{ matrix.go }})" >> $GITHUB_STEP_SUMMARY
+            echo "" >> $GITHUB_STEP_SUMMARY
+            echo "**Total Coverage: $COVERAGE**" >> $GITHUB_STEP_SUMMARY
+            echo "" >> $GITHUB_STEP_SUMMARY
+            
+            # Add coverage by package
+            echo "### 📋 Coverage by Package" >> $GITHUB_STEP_SUMMARY
+            echo "" >> $GITHUB_STEP_SUMMARY
+            echo "| Package | Coverage |" >> $GITHUB_STEP_SUMMARY
+            echo "|---------|----------|" >> $GITHUB_STEP_SUMMARY
+            
+            go tool cover -func=coverage.out | grep -v total | while read line; do
+              if [[ $line == *".go:"* ]]; then
+                pkg=$(echo $line | awk '{print $1}' | cut -d'/' -f1-3)
+                coverage=$(echo $line | awk '{print $3}')
+                echo "| $pkg | $coverage |" >> $GITHUB_STEP_SUMMARY
+              fi
+            done | sort -u
+            
+            echo "" >> $GITHUB_STEP_SUMMARY
+          else
+            echo "## ⚠️ Coverage Report" >> $GITHUB_STEP_SUMMARY
+            echo "No coverage file generated" >> $GITHUB_STEP_SUMMARY
+            echo "" >> $GITHUB_STEP_SUMMARY
+          fi
+
+      - name: Upload test artifacts
+        if: failure()
+        uses: actions/upload-artifact@v4
+        with:
+          name: test-results-go-${{ matrix.go }}
+          path: |
+            test-output.log
+            coverage.out
+            coverage.html
+          retention-days: 7

      - name: Run go vet
-        run: go vet ./...
+        run: |
+          echo "## 🔍 Static Analysis (Go ${{ matrix.go }})" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          
+          VET_OUTPUT=$(go vet ./... 2>&1 || echo "")
+          VET_STATUS=$?
+          
+          if [ $VET_STATUS -eq 0 ]; then
+            echo "✅ **go vet:** No issues found" >> $GITHUB_STEP_SUMMARY
+          else
+            echo "❌ **go vet:** Issues found" >> $GITHUB_STEP_SUMMARY
+            echo "" >> $GITHUB_STEP_SUMMARY
+            echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+            echo "$VET_OUTPUT" >> $GITHUB_STEP_SUMMARY
+            echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+          fi
+          echo "" >> $GITHUB_STEP_SUMMARY
+          
+          exit $VET_STATUS

      - name: Run go fmt
        run: |
-          if [ "$(gofmt -s -l . | wc -l)" -gt 0 ]; then
-            echo "The following files are not formatted:"
-            gofmt -s -l .
+          FMT_OUTPUT=$(gofmt -s -l . 2>&1 || echo "")
+          
+          if [ -z "$FMT_OUTPUT" ]; then
+            echo "✅ **go fmt:** All files properly formatted" >> $GITHUB_STEP_SUMMARY
+          else
+            echo "❌ **go fmt:** Files need formatting" >> $GITHUB_STEP_SUMMARY
+            echo "" >> $GITHUB_STEP_SUMMARY
+            echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+            echo "$FMT_OUTPUT" >> $GITHUB_STEP_SUMMARY
+            echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+            echo "" >> $GITHUB_STEP_SUMMARY
            exit 1
          fi

+      - name: Job Summary
+        if: always()
+        run: |
+          echo "## 📋 Job Summary (Go ${{ matrix.go }})" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "| Step | Status |" >> $GITHUB_STEP_SUMMARY
+          echo "|------|--------|" >> $GITHUB_STEP_SUMMARY
+          echo "| Dependencies | ✅ Success |" >> $GITHUB_STEP_SUMMARY
+          echo "| Build | ✅ Success |" >> $GITHUB_STEP_SUMMARY
+          echo "| Tests | ${{ steps.test.outcome == 'success' && '✅ Success' || '❌ Failed' }} |" >> $GITHUB_STEP_SUMMARY
+          echo "| Coverage | ${{ job.status == 'success' && '✅ Generated' || '⚠️ Partial' }} |" >> $GITHUB_STEP_SUMMARY
+          echo "| Static Analysis | ${{ job.status == 'success' && '✅ Clean' || '❌ Issues' }} |" >> $GITHUB_STEP_SUMMARY
+          echo "| Code Formatting | ${{ job.status == 'success' && '✅ Clean' || '❌ Issues' }} |" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+
      - name: Upload coverage reports to Codecov
        uses: codecov/codecov-action@v5
        with:
@ -81,9 +236,6 @@ jobs:
          fail-on-severity: moderate
          comment-summary-in-pr: always

-          # # Use comma-separated names to pass list arguments:
-          # deny-licenses: LGPL-2.0, BSD-2-Clause
-
  release:
    name: Release
    runs-on: ubuntu-latest
@ -103,7 +255,26 @@ jobs:
          check-latest: true

      - name: Run tests
-        run: go test -v ./...
+        run: |
+          echo "## 🚀 Release Tests" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          
+          go test -v ./... 2>&1 | tee release-test-output.log
+          TEST_STATUS=$?
+          
+          TOTAL_TESTS=$(grep -c "=== RUN" release-test-output.log || echo "0")
+          PASSED_TESTS=$(grep -c "--- PASS:" release-test-output.log || echo "0")
+          FAILED_TESTS=$(grep -c "--- FAIL:" release-test-output.log || echo "0")
+          
+          echo "| Metric | Value |" >> $GITHUB_STEP_SUMMARY
+          echo "|--------|-------|" >> $GITHUB_STEP_SUMMARY
+          echo "| Total Tests | $TOTAL_TESTS |" >> $GITHUB_STEP_SUMMARY
+          echo "| Passed | ✅ $PASSED_TESTS |" >> $GITHUB_STEP_SUMMARY
+          echo "| Failed | ❌ $FAILED_TESTS |" >> $GITHUB_STEP_SUMMARY
+          echo "| Status | $([ $TEST_STATUS -eq 0 ] && echo "✅ PASSED" || echo "❌ FAILED") |" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          
+          exit $TEST_STATUS

      - name: Install UPX
        run: |
@ -112,6 +283,9 @@ jobs:

      - name: Build binaries
        run: |
+          echo "## 🔨 Build Process" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          
          # Set the build time environment variable
          BUILD_TIME=$(date -u +'%Y-%m-%dT%H:%M:%SZ')

@ -121,6 +295,12 @@ jobs:
          # Display help information for the build script
          ./scripts/build.sh --help

+          echo "**Build Configuration:**" >> $GITHUB_STEP_SUMMARY
+          echo "- Version: ${{ github.ref_name }}" >> $GITHUB_STEP_SUMMARY
+          echo "- Build Time: $BUILD_TIME" >> $GITHUB_STEP_SUMMARY
+          echo "- Git Commit: ${{ github.sha }}" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+
          # Build for all platforms
          ./scripts/build.sh \
            --verbose \
@ -128,13 +308,18 @@ jobs:

      - name: Compress binaries with UPX
        run: |
+          echo "## 📦 Binary Compression" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          
          echo "Compressing binaries with UPX..."
          cd build/
          
          # Get original sizes
-          echo "Original sizes:"
-          ls -lah
-          echo ""
+          echo "**Original sizes:**" >> $GITHUB_STEP_SUMMARY
+          echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+          ls -lah >> $GITHUB_STEP_SUMMARY
+          echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
          
          # Compress all binaries except Darwin (macOS) binaries as UPX doesn't work well with recent macOS versions
          for binary in articulate-parser-*; do
@ -148,16 +333,16 @@ jobs:
            fi
          done
          
-          echo ""
-          echo "Final sizes:"
-          ls -lah
+          echo "**Final sizes:**" >> $GITHUB_STEP_SUMMARY
+          echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+          ls -lah >> $GITHUB_STEP_SUMMARY
+          echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY

      - name: Upload a Build Artifact
        uses: actions/upload-artifact@v4.6.2
        with:
-          # Artifact name
-          name: build-artifacts # optional, default is artifact
-          # A file, directory or wildcard pattern that describes what to upload
+          name: build-artifacts
          path: build/
          if-no-files-found: ignore
          retention-days: 1
--- a/.gitignore
+++ b/.gitignore
@ -26,11 +26,41 @@ go.work

 # End of https://www.toptal.com/developers/gitignore/api/go

+# Shit
+.github/TODO
+
 # Local test files
 output/
+outputs/
 articulate-sample.json
 test-output.*
 go-os-arch-matrix.csv
+test_godocx.go
+test_input.json

 # Build artifacts
 build/
+
+# Old workflows
+.github/workflows/ci-old.yml
+.github/workflows/ci-enhanced.yml
+
+# Test coverage files
+coverage.out
+coverage.txt
+coverage.html
+coverage.*
+coverage
+*.cover
+*.coverprofile
+main_coverage
+
+# Other common exclusions
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+*.test
+*.out
+/tmp/
--- a/README.md
+++ b/README.md
@ -1,23 +1,93 @@
 # Articulate Rise Parser

-A Go-based parser that converts Articulate Rise e-learning content to various formats including Markdown and Word documents.
+A Go-based parser that converts Articulate Rise e-learning content to various formats including Markdown, HTML, and Word documents.

 [![Go version](https://img.shields.io/github/go-mod/go-version/kjanat/articulate-parser?logo=Go&logoColor=white)][gomod]
 [![Go Doc](https://godoc.org/github.com/kjanat/articulate-parser?status.svg)][Package documentation]
 [![Go Report Card](https://goreportcard.com/badge/github.com/kjanat/articulate-parser)][Go report]
-[![Tag](https://img.shields.io/github/v/tag/kjanat/articulate-parser?sort=semver&label=Tag)][Tags]
-[![Release Date](https://img.shields.io/github/release-date/kjanat/articulate-parser?label=Release%20date)][Latest release]
-[![License](https://img.shields.io/github/license/kjanat/articulate-parser?label=License)](LICENSE)
-[![Commit activity](https://img.shields.io/github/commit-activity/m/kjanat/articulate-parser?label=Commit%20activity)][Commits]
+[![Tag](https://img.shields.io/github/v/tag/kjanat/articulate-parser?sort=semver&label=Tag)][Tags] <!-- [![Release Date](https://img.shields.io/github/release-date/kjanat/articulate-parser?label=Release%20date)][Latest release] -->
+[![License](https://img.shields.io/github/license/kjanat/articulate-parser?label=License)][MIT License] <!-- [![Commit activity](https://img.shields.io/github/commit-activity/m/kjanat/articulate-parser?label=Commit%20activity)][Commits] -->
 [![Last commit](https://img.shields.io/github/last-commit/kjanat/articulate-parser?label=Last%20commit)][Commits]
 [![GitHub Issues or Pull Requests](https://img.shields.io/github/issues/kjanat/articulate-parser?label=Issues)][Issues]
 [![CI](https://img.shields.io/github/actions/workflow/status/kjanat/articulate-parser/ci.yml?logo=github&label=CI)][Build]
 [![Codecov](https://img.shields.io/codecov/c/gh/kjanat/articulate-parser?token=eHhaHY8nut&logo=codecov&logoColor=%23F01F7A&label=Codecov)][Codecov]

+## System Architecture
+
+```mermaid
+flowchart TD
+    %% User Input
+    CLI[Command Line Interface<br/>main.go] --> APP{App Service<br/>services/app.go}
+    
+    %% Core Application Logic
+    APP --> |"ProcessCourseFromURI"| PARSER[Course Parser<br/>services/parser.go]
+    APP --> |"ProcessCourseFromFile"| PARSER
+    APP --> |"exportCourse"| FACTORY[Exporter Factory<br/>exporters/factory.go]
+    
+    %% Data Sources
+    PARSER --> |"FetchCourse"| API[Articulate Rise API<br/>rise.articulate.com]
+    PARSER --> |"LoadCourseFromFile"| FILE[Local JSON File<br/>*.json]
+    
+    %% Data Models
+    API --> MODELS[Data Models<br/>models/course.go]
+    FILE --> MODELS
+    MODELS --> |Course, Lesson, Item| APP
+    
+    %% Export Factory Pattern
+    FACTORY --> |"CreateExporter"| MARKDOWN[Markdown Exporter<br/>exporters/markdown.go]
+    FACTORY --> |"CreateExporter"| HTML[HTML Exporter<br/>exporters/html.go]
+    FACTORY --> |"CreateExporter"| DOCX[DOCX Exporter<br/>exporters/docx.go]
+    
+    %% HTML Cleaning Service
+    CLEANER[HTML Cleaner<br/>services/html_cleaner.go] --> MARKDOWN
+    CLEANER --> HTML
+    CLEANER --> DOCX
+    
+    %% Output Files
+    MARKDOWN --> |"Export"| MD_OUT[Markdown Files<br/>*.md]
+    HTML --> |"Export"| HTML_OUT[HTML Files<br/>*.html]
+    DOCX --> |"Export"| DOCX_OUT[Word Documents<br/>*.docx]
+    
+    %% Interfaces (Contracts)
+    IPARSER[CourseParser Interface<br/>interfaces/parser.go] -.-> PARSER
+    IEXPORTER[Exporter Interface<br/>interfaces/exporter.go] -.-> MARKDOWN
+    IEXPORTER -.-> HTML
+    IEXPORTER -.-> DOCX
+    IFACTORY[ExporterFactory Interface<br/>interfaces/exporter.go] -.-> FACTORY
+      %% Styling - Colors that work in both light and dark GitHub themes
+    classDef userInput fill:#dbeafe,stroke:#1e40af,stroke-width:2px,color:#1e40af
+    classDef coreLogic fill:#ede9fe,stroke:#6d28d9,stroke-width:2px,color:#6d28d9
+    classDef dataSource fill:#d1fae5,stroke:#059669,stroke-width:2px,color:#059669
+    classDef exporter fill:#fed7aa,stroke:#ea580c,stroke-width:2px,color:#ea580c
+    classDef output fill:#fce7f3,stroke:#be185d,stroke-width:2px,color:#be185d
+    classDef interface fill:#ecfdf5,stroke:#16a34a,stroke-width:1px,stroke-dasharray: 5 5,color:#16a34a
+    classDef service fill:#cffafe,stroke:#0891b2,stroke-width:2px,color:#0891b2
+    
+    class CLI userInput
+    class APP,FACTORY coreLogic
+    class API,FILE,MODELS dataSource
+    class MARKDOWN,HTML,DOCX exporter
+    class MD_OUT,HTML_OUT,DOCX_OUT output
+    class IPARSER,IEXPORTER,IFACTORY interface
+    class PARSER,CLEANER service
+```
+
+### Architecture Overview
+
+The system follows **Clean Architecture** principles with clear separation of concerns:
+
+-   **🎯 Entry Point**: Command-line interface handles user input and coordinates operations
+-   **🏗️ Application Layer**: Core business logic with dependency injection
+-   **📋 Interface Layer**: Contracts defining behavior without implementation details  
+-   **🔧 Service Layer**: Concrete implementations of parsing and utility services
+-   **📤 Export Layer**: Factory pattern for format-specific exporters
+-   **📊 Data Layer**: Domain models representing course structure
+
 ## Features

 -   Parse Articulate Rise JSON data from URLs or local files
 -   Export to Markdown (.md) format
+-   Export to HTML (.html) format with professional styling
 -   Export to Word Document (.docx) format
 -   Support for various content types:
    -   Text content with headings and paragraphs
@ -29,20 +99,50 @@ A Go-based parser that converts Articulate Rise e-learning content to various fo

 ## Installation

-1.  Ensure you have Go 1.21 or later installed
-2.  Clone or download the parser code
-3.  Initialize the Go module:
+### Prerequisites
+
+-   Go, I don't know the version, but I use go1.24.2 right now, and it works, see the [CI][Build] workflow where it is tested.
+
+### Install from source

 ```bash
-go mod init articulate-parser
-go mod tidy
+git clone https://github.com/kjanat/articulate-parser.git
+cd articulate-parser
+go mod download
+go build -o articulate-parser main.go
+```
+
+### Or install directly
+
+```bash
+go install github.com/kjanat/articulate-parser@latest
 ```

 ## Dependencies

 The parser uses the following external library:

-   `github.com/unidoc/unioffice` - For creating Word documents
+-   `github.com/fumiama/go-docx` - For creating Word documents (MIT license)
+
+## Testing
+
+Run the test suite:
+
+```bash
+go test ./...
+```
+
+Run tests with coverage:
+
+```bash
+go test -v -race -coverprofile=coverage.out ./...
+```
+
+View coverage report:
+
+```bash
+go tool cover -html=coverage.out
+```

 ## Usage

@ -54,9 +154,11 @@ go run main.go <input_uri_or_file> <output_format> [output_path]

 #### Parameters

-   `input_uri_or_file`: Either an Articulate Rise share URL or path to a local JSON file
-   `output_format`: `md` for Markdown or `docx` for Word Document
-   `output_path`: Optional. If not provided, files are saved to `./output/` directory
+| Parameter           | Description                                                      | Default         |
+| ------------------- | ---------------------------------------------------------------- | --------------- |
+| `input_uri_or_file` | Either an Articulate Rise share URL or path to a local JSON file | None (required) |
+| `output_format`     | `md` for Markdown, `html` for HTML, or `docx` for Word Document  | None (required) |
+| `output_path`       | Path where output file will be saved.                            | `./output/`     |

 #### Examples

@ -72,10 +174,16 @@ go run main.go "https://rise.articulate.com/share/N_APNg40Vr2CSH2xNz-ZLATM5kNviD
 go run main.go "articulate-sample.json" docx "my-course.docx"
 ```

-3.  **Parse from local file and export to Markdown:**
+3.  **Parse from local file and export to HTML:**

 ```bash
-go run main.go "C:\Users\kjana\Projects\articulate-parser\articulate-sample.json" md
+go run main.go "articulate-sample.json" html "output.html"
+```
+
+4.  **Parse from local file and export to Markdown:**
+
+```bash
+go run main.go "articulate-sample.json" md "output.md"
 ```

 ### Building the Executable
@ -92,9 +200,29 @@ Then run:
 ./articulate-parser input.json md output.md
 ```

+## Development
+
+### Code Quality
+
+The project maintains high code quality standards:
+
+-   Cyclomatic complexity ≤ 15 (checked with [gocyclo](https://github.com/fzipp/gocyclo))
+-   Race condition detection enabled
+-   Comprehensive test coverage
+-   Code formatting with `gofmt`
+-   Static analysis with `go vet`
+
+### Contributing
+
+1.  Fork the repository
+2.  Create a feature branch
+3.  Make your changes
+4.  Run tests: `go test ./...`
+5.  Submit a pull request
+
 ## Output Formats

-### Markdown (.md)
+### Markdown (`.md`)

 -   Hierarchical structure with proper heading levels
 -   Clean text content with HTML tags removed
@ -103,7 +231,16 @@ Then run:
 -   Media references included
 -   Course metadata at the top

-### Word Document (.docx)
+### HTML (`.html`)
+
+-   Professional styling with embedded CSS
+-   Interactive and visually appealing layout
+-   Proper HTML structure with semantic elements
+-   Responsive design for different screen sizes
+-   All content types beautifully formatted
+-   Maintains course hierarchy and organization
+
+### Word Document (`.docx`)

 -   Professional document formatting
 -   Bold headings and proper typography
@ -154,7 +291,7 @@ The parser includes error handling for:

 <!-- ## Code coverage

-![Sunburst](https://codecov.io/gh/kjanat/articulate-parser/graphs/tree.svg?token=eHhaHY8nut)
+![Sunburst](https://codecov.io/gh/kjanat/articulate-parser/graphs/sunburst.svg?token=eHhaHY8nut)

 ![Grid](https://codecov.io/gh/kjanat/articulate-parser/graphs/tree.svg?token=eHhaHY8nut)

@ -167,16 +304,23 @@ The parser includes error handling for:
 -   Styling and visual formatting is not preserved
 -   Assessment logic and interactivity is lost in static exports

+## Performance
+
+-   Lightweight with minimal dependencies
+-   Fast JSON parsing and export
+-   Memory efficient processing
+-   No external license requirements
+
 ## Future Enhancements

 Potential improvements could include:

-   PDF export support
-   Media file downloading
-   HTML export with preserved styling
-   SCORM package support
-   Batch processing capabilities
-   Custom template support
+-   [ ]  PDF export support
+-   [ ]  Media file downloading
+-   [x]  ~~HTML export with preserved styling~~
+-   [ ]  SCORM package support
+-   [ ]  Batch processing capabilities
+-   [ ]  Custom template support

 ## License

@ -188,6 +332,7 @@ This is a utility tool for educational content conversion. Please ensure you hav
 [Go report]: https://goreportcard.com/report/github.com/kjanat/articulate-parser
 [gomod]: go.mod
 [Issues]: https://github.com/kjanat/articulate-parser/issues
-[Latest release]: https://github.com/kjanat/articulate-parser/releases/latest
+<!-- [Latest release]: https://github.com/kjanat/articulate-parser/releases/latest -->
+[MIT License]: LICENSE
 [Package documentation]: https://godoc.org/github.com/kjanat/articulate-parser
 [Tags]: https://github.com/kjanat/articulate-parser/tags
--- a/go.mod
+++ b/go.mod
@ -1,7 +1,10 @@
 module github.com/kjanat/articulate-parser

-go 1.21
+go 1.23.0

-require github.com/unidoc/unioffice v1.39.0
+require github.com/fumiama/go-docx v0.0.0-20250506085032-0c30fd09304b

-require github.com/richardlehane/msoleps v1.0.4 // indirect
+require (
+	github.com/fumiama/imgsz v0.0.4 // indirect
+	golang.org/x/image v0.27.0 // indirect
+)
--- a/go.sum
+++ b/go.sum
@ -1,6 +1,6 @@
-github.com/richardlehane/msoleps v1.0.3 h1:aznSZzrwYRl3rLKRT3gUk9am7T/mLNSnJINvN0AQoVM=
-github.com/richardlehane/msoleps v1.0.3/go.mod h1:BWev5JBpU9Ko2WAgmZEuiz4/u3ZYTKbjLycmwiWUfWg=
-github.com/richardlehane/msoleps v1.0.4 h1:WuESlvhX3gH2IHcd8UqyCuFY5yiq/GR/yqaSM/9/g00=
-github.com/richardlehane/msoleps v1.0.4/go.mod h1:BWev5JBpU9Ko2WAgmZEuiz4/u3ZYTKbjLycmwiWUfWg=
-github.com/unidoc/unioffice v1.39.0 h1:Wo5zvrzCqhyK/1Zi5dg8a5F5+NRftIMZPnFPYwruLto=
-github.com/unidoc/unioffice v1.39.0/go.mod h1:Axz6ltIZZTUUyHoEnPe4Mb3VmsN4TRHT5iZCGZ1rgnU=
+github.com/fumiama/go-docx v0.0.0-20250506085032-0c30fd09304b h1:/mxSugRc4SgN7XgBtT19dAJ7cAXLTbPmlJLJE4JjRkE=
+github.com/fumiama/go-docx v0.0.0-20250506085032-0c30fd09304b/go.mod h1:ssRF0IaB1hCcKIObp3FkZOsjTcAHpgii70JelNb4H8M=
+github.com/fumiama/imgsz v0.0.4 h1:Lsasu2hdSSFS+vnD+nvR1UkiRMK7hcpyYCC0FzgSMFI=
+github.com/fumiama/imgsz v0.0.4/go.mod h1:bISOQVTlw9sRytPwe8ir7tAaEmyz9hSNj9n8mXMBG0E=
+golang.org/x/image v0.27.0 h1:C8gA4oWU/tKkdCfYT6T2u4faJu3MeNS5O8UPWlPF61w=
+golang.org/x/image v0.27.0/go.mod h1:xbdrClrAUway1MUTEZDq9mz/UpRwYAkFFNUslZtcB+g=
--- a/internal/exporters/docx.go
+++ b/internal/exporters/docx.go
@ -4,17 +4,18 @@ package exporters

 import (
 	"fmt"
+	"os"
 	"strings"

+	"github.com/fumiama/go-docx"
 	"github.com/kjanat/articulate-parser/internal/interfaces"
 	"github.com/kjanat/articulate-parser/internal/models"
 	"github.com/kjanat/articulate-parser/internal/services"
-	"github.com/unidoc/unioffice/document"
 )

 // DocxExporter implements the Exporter interface for DOCX format.
 // It converts Articulate Rise course data into a Microsoft Word document
-// using the unioffice/document package.
+// using the go-docx package.
 type DocxExporter struct {
 	// htmlCleaner is used to convert HTML content to plain text
 	htmlCleaner *services.HTMLCleaner
@ -45,21 +46,17 @@ func NewDocxExporter(htmlCleaner *services.HTMLCleaner) interfaces.Exporter {
 // Returns:
 //   - An error if creating or saving the document fails
 func (e *DocxExporter) Export(course *models.Course, outputPath string) error {
-	doc := document.New()
+	doc := docx.New()

 	// Add title
 	titlePara := doc.AddParagraph()
-	titleRun := titlePara.AddRun()
-	titleRun.AddText(course.Course.Title)
-	titleRun.Properties().SetBold(true)
-	titleRun.Properties().SetSize(16)
+	titlePara.AddText(course.Course.Title).Size("32").Bold()

 	// Add description if available
 	if course.Course.Description != "" {
 		descPara := doc.AddParagraph()
-		descRun := descPara.AddRun()
 		cleanDesc := e.htmlCleaner.CleanHTML(course.Course.Description)
-		descRun.AddText(cleanDesc)
+		descPara.AddText(cleanDesc)
 	}

 	// Add each lesson
@ -72,7 +69,20 @@ func (e *DocxExporter) Export(course *models.Course, outputPath string) error {
 		outputPath = outputPath + ".docx"
 	}

-	return doc.SaveToFile(outputPath)
+	// Create the file
+	file, err := os.Create(outputPath)
+	if err != nil {
+		return fmt.Errorf("failed to create output file: %w", err)
+	}
+	defer file.Close()
+
+	// Save the document
+	_, err = doc.WriteTo(file)
+	if err != nil {
+		return fmt.Errorf("failed to save document: %w", err)
+	}
+
+	return nil
 }

 // exportLesson adds a lesson to the document with appropriate formatting.
@ -81,20 +91,16 @@ func (e *DocxExporter) Export(course *models.Course, outputPath string) error {
 // Parameters:
 //   - doc: The Word document being created
 //   - lesson: The lesson data model to export
-func (e *DocxExporter) exportLesson(doc *document.Document, lesson *models.Lesson) {
+func (e *DocxExporter) exportLesson(doc *docx.Docx, lesson *models.Lesson) {
 	// Add lesson title
 	lessonPara := doc.AddParagraph()
-	lessonRun := lessonPara.AddRun()
-	lessonRun.AddText(fmt.Sprintf("Lesson: %s", lesson.Title))
-	lessonRun.Properties().SetBold(true)
-	lessonRun.Properties().SetSize(14)
+	lessonPara.AddText(fmt.Sprintf("Lesson: %s", lesson.Title)).Size("28").Bold()

 	// Add lesson description if available
 	if lesson.Description != "" {
 		descPara := doc.AddParagraph()
-		descRun := descPara.AddRun()
 		cleanDesc := e.htmlCleaner.CleanHTML(lesson.Description)
-		descRun.AddText(cleanDesc)
+		descPara.AddText(cleanDesc)
 	}

 	// Add each item in the lesson
@ -109,14 +115,11 @@ func (e *DocxExporter) exportLesson(doc *document.Document, lesson *models.Lesso
 // Parameters:
 //   - doc: The Word document being created
 //   - item: The item data model to export
-func (e *DocxExporter) exportItem(doc *document.Document, item *models.Item) {
+func (e *DocxExporter) exportItem(doc *docx.Docx, item *models.Item) {
 	// Add item type as heading
 	if item.Type != "" {
 		itemPara := doc.AddParagraph()
-		itemRun := itemPara.AddRun()
-		itemRun.AddText(strings.Title(item.Type))
-		itemRun.Properties().SetBold(true)
-		itemRun.Properties().SetSize(12)
+		itemPara.AddText(strings.Title(item.Type)).Size("24").Bold()
 	}

 	// Add sub-items
@ -132,58 +135,48 @@ func (e *DocxExporter) exportItem(doc *document.Document, item *models.Item) {
 // Parameters:
 //   - doc: The Word document being created
 //   - subItem: The sub-item data model to export
-func (e *DocxExporter) exportSubItem(doc *document.Document, subItem *models.SubItem) {
+func (e *DocxExporter) exportSubItem(doc *docx.Docx, subItem *models.SubItem) {
 	// Add title if available
 	if subItem.Title != "" {
 		subItemPara := doc.AddParagraph()
-		subItemRun := subItemPara.AddRun()
-		subItemRun.AddText("  " + subItem.Title) // Indented
-		subItemRun.Properties().SetBold(true)
+		subItemPara.AddText("  " + subItem.Title).Bold() // Indented
 	}

 	// Add heading if available
 	if subItem.Heading != "" {
 		headingPara := doc.AddParagraph()
-		headingRun := headingPara.AddRun()
 		cleanHeading := e.htmlCleaner.CleanHTML(subItem.Heading)
-		headingRun.AddText("  " + cleanHeading) // Indented
-		headingRun.Properties().SetBold(true)
+		headingPara.AddText("  " + cleanHeading).Bold() // Indented
 	}

 	// Add paragraph content if available
 	if subItem.Paragraph != "" {
 		contentPara := doc.AddParagraph()
-		contentRun := contentPara.AddRun()
 		cleanContent := e.htmlCleaner.CleanHTML(subItem.Paragraph)
-		contentRun.AddText("  " + cleanContent) // Indented
+		contentPara.AddText("  " + cleanContent) // Indented
 	}

 	// Add answers if this is a question
 	if len(subItem.Answers) > 0 {
 		answersPara := doc.AddParagraph()
-		answersRun := answersPara.AddRun()
-		answersRun.AddText("  Answers:")
-		answersRun.Properties().SetBold(true)
+		answersPara.AddText("  Answers:").Bold()

 		for i, answer := range subItem.Answers {
 			answerPara := doc.AddParagraph()
-			answerRun := answerPara.AddRun()
 			prefix := fmt.Sprintf("    %d. ", i+1)
 			if answer.Correct {
 				prefix += "✓ "
 			}
 			cleanAnswer := e.htmlCleaner.CleanHTML(answer.Title)
-			answerRun.AddText(prefix + cleanAnswer)
+			answerPara.AddText(prefix + cleanAnswer)
 		}
 	}

 	// Add feedback if available
 	if subItem.Feedback != "" {
 		feedbackPara := doc.AddParagraph()
-		feedbackRun := feedbackPara.AddRun()
 		cleanFeedback := e.htmlCleaner.CleanHTML(subItem.Feedback)
-		feedbackRun.AddText("  Feedback: " + cleanFeedback)
-		feedbackRun.Properties().SetItalic(true)
+		feedbackPara.AddText("  Feedback: " + cleanFeedback).Italic()
 	}
 }

--- a/internal/exporters/docx_test.go
+++ b/internal/exporters/docx_test.go
@ -0,0 +1,679 @@
+// Package exporters_test provides tests for the docx exporter.
+package exporters
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/kjanat/articulate-parser/internal/models"
+	"github.com/kjanat/articulate-parser/internal/services"
+)
+
+// TestNewDocxExporter tests the NewDocxExporter constructor.
+func TestNewDocxExporter(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	if exporter == nil {
+		t.Fatal("NewDocxExporter() returned nil")
+	}
+
+	// Type assertion to check internal structure
+	docxExporter, ok := exporter.(*DocxExporter)
+	if !ok {
+		t.Fatal("NewDocxExporter() returned wrong type")
+	}
+
+	if docxExporter.htmlCleaner == nil {
+		t.Error("htmlCleaner should not be nil")
+	}
+}
+
+// TestDocxExporter_GetSupportedFormat tests the GetSupportedFormat method.
+func TestDocxExporter_GetSupportedFormat(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	expected := "docx"
+	result := exporter.GetSupportedFormat()
+
+	if result != expected {
+		t.Errorf("Expected format '%s', got '%s'", expected, result)
+	}
+}
+
+// TestDocxExporter_Export tests the Export method.
+func TestDocxExporter_Export(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	// Create test course
+	testCourse := createTestCourseForDocx()
+
+	// Create temporary directory and file
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "test-course.docx")
+
+	// Test successful export
+	err := exporter.Export(testCourse, outputPath)
+	if err != nil {
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Check that file was created
+	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+		t.Fatal("Output file was not created")
+	}
+
+	// Verify file has some content (basic check)
+	fileInfo, err := os.Stat(outputPath)
+	if err != nil {
+		t.Fatalf("Failed to get file info: %v", err)
+	}
+
+	if fileInfo.Size() == 0 {
+		t.Error("Output file is empty")
+	}
+}
+
+// TestDocxExporter_Export_AddDocxExtension tests that the .docx extension is added automatically.
+func TestDocxExporter_Export_AddDocxExtension(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	testCourse := createTestCourseForDocx()
+
+	// Create temporary directory and file without .docx extension
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "test-course")
+
+	err := exporter.Export(testCourse, outputPath)
+	if err != nil {
+
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Check that file was created with .docx extension
+	expectedPath := outputPath + ".docx"
+	if _, err := os.Stat(expectedPath); os.IsNotExist(err) {
+		t.Fatal("Output file with .docx extension was not created")
+	}
+}
+
+// TestDocxExporter_Export_InvalidPath tests export with invalid output path.
+func TestDocxExporter_Export_InvalidPath(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	testCourse := createTestCourseForDocx()
+
+	// Try to write to invalid path
+	invalidPath := "/invalid/path/that/does/not/exist/file.docx"
+	err := exporter.Export(testCourse, invalidPath)
+
+	if err == nil {
+		t.Fatal("Expected error for invalid path, got nil")
+	}
+}
+
+// TestDocxExporter_ExportLesson tests the exportLesson method indirectly through Export.
+func TestDocxExporter_ExportLesson(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	// Create course with specific lesson content
+	course := &models.Course{
+		ShareID: "test-id",
+		Course: models.CourseInfo{
+			ID:    "test-course",
+			Title: "Test Course",
+			Lessons: []models.Lesson{
+				{
+					ID:          "lesson-1",
+					Title:       "Test Lesson",
+					Type:        "lesson",
+					Description: "<p>Test lesson description with <strong>bold</strong> text.</p>",
+					Items: []models.Item{
+						{
+							Type: "text",
+							Items: []models.SubItem{
+								{
+									Title:     "Test Item Title",
+									Paragraph: "<p>Test paragraph content.</p>",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "lesson-test.docx")
+
+	err := exporter.Export(course, outputPath)
+	if err != nil {
+
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Verify file was created successfully
+	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+		t.Fatal("Output file was not created")
+	}
+}
+
+// TestDocxExporter_ExportItem tests the exportItem method indirectly through Export.
+func TestDocxExporter_ExportItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	// Create course with different item types
+	course := &models.Course{
+		ShareID: "test-id",
+		Course: models.CourseInfo{
+			ID:    "test-course",
+			Title: "Item Test Course",
+			Lessons: []models.Lesson{
+				{
+					ID:    "lesson-1",
+					Title: "Item Types Lesson",
+					Type:  "lesson",
+					Items: []models.Item{
+						{
+							Type: "text",
+							Items: []models.SubItem{
+								{
+									Title:     "Text Item",
+									Paragraph: "<p>Text content</p>",
+								},
+							},
+						},
+						{
+							Type: "list",
+							Items: []models.SubItem{
+								{Paragraph: "<p>List item 1</p>"},
+								{Paragraph: "<p>List item 2</p>"},
+							},
+						},
+						{
+							Type: "knowledgeCheck",
+							Items: []models.SubItem{
+								{
+									Title: "<p>What is the answer?</p>",
+									Answers: []models.Answer{
+										{Title: "Option A", Correct: false},
+										{Title: "Option B", Correct: true},
+									},
+									Feedback: "<p>Correct answer explanation</p>",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "items-test.docx")
+
+	err := exporter.Export(course, outputPath)
+	if err != nil {
+
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Verify file was created successfully
+	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+		t.Fatal("Output file was not created")
+	}
+}
+
+// TestDocxExporter_ExportSubItem tests the exportSubItem method indirectly through Export.
+func TestDocxExporter_ExportSubItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	// Create course with sub-item containing all possible fields
+	course := &models.Course{
+		ShareID: "test-id",
+		Course: models.CourseInfo{
+			ID:    "test-course",
+			Title: "SubItem Test Course",
+			Lessons: []models.Lesson{
+				{
+					ID:    "lesson-1",
+					Title: "SubItem Test Lesson",
+					Type:  "lesson",
+					Items: []models.Item{
+						{
+							Type: "knowledgeCheck",
+							Items: []models.SubItem{
+								{
+									Title:     "<p>Question Title</p>",
+									Heading:   "<h3>Question Heading</h3>",
+									Paragraph: "<p>Question description with <em>emphasis</em>.</p>",
+									Answers: []models.Answer{
+										{Title: "Wrong answer", Correct: false},
+										{Title: "Correct answer", Correct: true},
+										{Title: "Another wrong answer", Correct: false},
+									},
+									Feedback: "<p>Feedback with <strong>formatting</strong>.</p>",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "subitem-test.docx")
+
+	err := exporter.Export(course, outputPath)
+	if err != nil {
+
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Verify file was created successfully
+	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+		t.Fatal("Output file was not created")
+	}
+}
+
+// TestDocxExporter_ComplexCourse tests export of a complex course structure.
+func TestDocxExporter_ComplexCourse(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	// Create complex test course
+	course := &models.Course{
+		ShareID: "complex-test-id",
+		Course: models.CourseInfo{
+			ID:          "complex-course",
+			Title:       "Complex Test Course",
+			Description: "<p>This is a <strong>complex</strong> course description with <em>formatting</em>.</p>",
+			Lessons: []models.Lesson{
+				{
+					ID:    "section-1",
+					Title: "Course Section",
+					Type:  "section",
+				},
+				{
+					ID:          "lesson-1",
+					Title:       "Introduction Lesson",
+					Type:        "lesson",
+					Description: "<p>Introduction to the course with <code>code</code> and <a href='#'>links</a>.</p>",
+					Items: []models.Item{
+						{
+							Type: "text",
+							Items: []models.SubItem{
+								{
+									Heading:   "<h2>Welcome</h2>",
+									Paragraph: "<p>Welcome to our comprehensive course!</p>",
+								},
+							},
+						},
+						{
+							Type: "list",
+							Items: []models.SubItem{
+								{Paragraph: "<p>Learn advanced concepts</p>"},
+								{Paragraph: "<p>Practice with real examples</p>"},
+								{Paragraph: "<p>Apply knowledge in projects</p>"},
+							},
+						},
+						{
+							Type: "multimedia",
+							Items: []models.SubItem{
+								{
+									Title:   "<p>Video Introduction</p>",
+									Caption: "<p>Watch this introductory video</p>",
+									Media: &models.Media{
+										Video: &models.VideoMedia{
+											OriginalUrl: "https://example.com/intro.mp4",
+											Duration:    300,
+										},
+									},
+								},
+							},
+						},
+						{
+							Type: "knowledgeCheck",
+							Items: []models.SubItem{
+								{
+									Title: "<p>What will you learn in this course?</p>",
+									Answers: []models.Answer{
+										{Title: "Basic concepts only", Correct: false},
+										{Title: "Advanced concepts and practical application", Correct: true},
+										{Title: "Theory without practice", Correct: false},
+									},
+									Feedback: "<p>Excellent! This course covers both theory and practice.</p>",
+								},
+							},
+						},
+						{
+							Type: "image",
+							Items: []models.SubItem{
+								{
+									Caption: "<p>Course overview diagram</p>",
+									Media: &models.Media{
+										Image: &models.ImageMedia{
+											OriginalUrl: "https://example.com/overview.png",
+										},
+									},
+								},
+							},
+						},
+						{
+							Type: "interactive",
+							Items: []models.SubItem{
+								{
+									Title: "<p>Interactive Exercise</p>",
+								},
+							},
+						},
+					},
+				},
+				{
+					ID:    "lesson-2",
+					Title: "Advanced Topics",
+					Type:  "lesson",
+					Items: []models.Item{
+						{
+							Type: "divider",
+						},
+						{
+							Type: "unknown",
+							Items: []models.SubItem{
+								{
+									Title:     "<p>Custom Content</p>",
+									Paragraph: "<p>This is custom content type</p>",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	// Create temporary output file
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "complex-course.docx")
+
+	// Export course
+	err := exporter.Export(course, outputPath)
+	if err != nil {
+
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Verify file was created and has reasonable size
+	fileInfo, err := os.Stat(outputPath)
+	if err != nil {
+		t.Fatalf("Failed to get file info: %v", err)
+	}
+
+	if fileInfo.Size() < 1000 {
+		t.Error("Output file seems too small for complex course content")
+	}
+}
+
+// TestDocxExporter_EmptyCourse tests export of an empty course.
+func TestDocxExporter_EmptyCourse(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	// Create minimal course
+	course := &models.Course{
+		ShareID: "empty-id",
+		Course: models.CourseInfo{
+			ID:      "empty-course",
+			Title:   "Empty Course",
+			Lessons: []models.Lesson{},
+		},
+	}
+
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "empty-course.docx")
+
+	err := exporter.Export(course, outputPath)
+	if err != nil {
+
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Verify file was created
+	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+		t.Fatal("Output file was not created")
+	}
+}
+
+// TestDocxExporter_HTMLCleaning tests that HTML content is properly cleaned.
+func TestDocxExporter_HTMLCleaning(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	// Create course with HTML content that needs cleaning
+	course := &models.Course{
+		ShareID: "html-test-id",
+		Course: models.CourseInfo{
+			ID:          "html-test-course",
+			Title:       "HTML Cleaning Test",
+			Description: "<p>Description with <script>alert('xss')</script> and <b>bold</b> text.</p>",
+			Lessons: []models.Lesson{
+				{
+					ID:          "lesson-1",
+					Title:       "Test Lesson",
+					Type:        "lesson",
+					Description: "<div>Lesson description with <span style='color:red'>styled</span> content.</div>",
+					Items: []models.Item{
+						{
+							Type: "text",
+							Items: []models.SubItem{
+								{
+									Heading:   "<h1>Heading with <em>emphasis</em> and &amp; entities</h1>",
+									Paragraph: "<p>Paragraph with &lt;code&gt; entities and <strong>formatting</strong>.</p>",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "html-cleaning-test.docx")
+
+	err := exporter.Export(course, outputPath)
+	if err != nil {
+
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Verify file was created (basic check that HTML cleaning didn't break export)
+	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+		t.Fatal("Output file was not created")
+	}
+}
+
+// TestDocxExporter_ExistingDocxExtension tests that existing .docx extension is preserved.
+func TestDocxExporter_ExistingDocxExtension(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	testCourse := createTestCourseForDocx()
+
+	// Use path that already has .docx extension
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "test-course.docx")
+
+	err := exporter.Export(testCourse, outputPath)
+	if err != nil {
+
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Check that file was created at the exact path (no double extension)
+	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+		t.Fatal("Output file was not created at expected path")
+	}
+
+	// Ensure no double extension was created
+	doubleExtensionPath := outputPath + ".docx"
+	if _, err := os.Stat(doubleExtensionPath); err == nil {
+		t.Error("Double .docx extension file should not exist")
+	}
+}
+
+// TestDocxExporter_CaseInsensitiveExtension tests that extension checking is case-insensitive.
+func TestDocxExporter_CaseInsensitiveExtension(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	testCourse := createTestCourseForDocx()
+
+	// Test various case combinations
+	testCases := []string{
+		"test-course.DOCX",
+		"test-course.Docx",
+		"test-course.DocX",
+	}
+
+	for i, testCase := range testCases {
+		tempDir := t.TempDir()
+		outputPath := filepath.Join(tempDir, testCase)
+
+		err := exporter.Export(testCourse, outputPath)
+		if err != nil {
+
+			t.Fatalf("Export failed for case %d (%s): %v", i, testCase, err)
+		}
+
+		// Check that file was created at the exact path (no additional extension)
+		if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+			t.Fatalf("Output file was not created at expected path for case %d (%s)", i, testCase)
+		}
+	}
+}
+
+// createTestCourseForDocx creates a test course for DOCX export testing.
+func createTestCourseForDocx() *models.Course {
+	return &models.Course{
+		ShareID: "test-share-id",
+		Course: models.CourseInfo{
+			ID:          "test-course-id",
+			Title:       "Test Course",
+			Description: "<p>Test course description with <strong>formatting</strong>.</p>",
+			Lessons: []models.Lesson{
+				{
+					ID:    "section-1",
+					Title: "Test Section",
+					Type:  "section",
+				},
+				{
+					ID:          "lesson-1",
+					Title:       "Test Lesson",
+					Type:        "lesson",
+					Description: "<p>Test lesson description</p>",
+					Items: []models.Item{
+						{
+							Type: "text",
+							Items: []models.SubItem{
+								{
+									Heading:   "<h2>Test Heading</h2>",
+									Paragraph: "<p>Test paragraph content.</p>",
+								},
+							},
+						},
+						{
+							Type: "list",
+							Items: []models.SubItem{
+								{Paragraph: "<p>First list item</p>"},
+								{Paragraph: "<p>Second list item</p>"},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+// BenchmarkDocxExporter_Export benchmarks the Export method.
+func BenchmarkDocxExporter_Export(b *testing.B) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+	course := createTestCourseForDocx()
+
+	// Create temporary directory
+	tempDir := b.TempDir()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		outputPath := filepath.Join(tempDir, "benchmark-course.docx")
+		_ = exporter.Export(course, outputPath)
+		// Clean up for next iteration
+		os.Remove(outputPath)
+	}
+}
+
+// BenchmarkDocxExporter_ComplexCourse benchmarks export of a complex course.
+func BenchmarkDocxExporter_ComplexCourse(b *testing.B) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewDocxExporter(htmlCleaner)
+
+	// Create complex course for benchmarking
+	course := &models.Course{
+		ShareID: "benchmark-id",
+		Course: models.CourseInfo{
+			ID:          "benchmark-course",
+			Title:       "Benchmark Course",
+			Description: "<p>Complex course for performance testing</p>",
+			Lessons:     make([]models.Lesson, 10), // 10 lessons
+		},
+	}
+
+	// Fill with test data
+	for i := 0; i < 10; i++ {
+		lesson := models.Lesson{
+			ID:    "lesson-" + string(rune(i)),
+			Title: "Lesson " + string(rune(i)),
+			Type:  "lesson",
+			Items: make([]models.Item, 5), // 5 items per lesson
+		}
+
+		for j := 0; j < 5; j++ {
+			item := models.Item{
+				Type:  "text",
+				Items: make([]models.SubItem, 3), // 3 sub-items per item
+			}
+
+			for k := 0; k < 3; k++ {
+				item.Items[k] = models.SubItem{
+					Heading:   "<h3>Heading " + string(rune(k)) + "</h3>",
+					Paragraph: "<p>Paragraph content with <strong>formatting</strong> for performance testing.</p>",
+				}
+			}
+
+			lesson.Items[j] = item
+		}
+
+		course.Course.Lessons[i] = lesson
+	}
+
+	tempDir := b.TempDir()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		outputPath := filepath.Join(tempDir, "benchmark-complex.docx")
+		_ = exporter.Export(course, outputPath)
+		os.Remove(outputPath)
+	}
+}
--- a/internal/exporters/factory.go
+++ b/internal/exporters/factory.go
@ -48,6 +48,8 @@ func (f *Factory) CreateExporter(format string) (interfaces.Exporter, error) {
 		return NewMarkdownExporter(f.htmlCleaner), nil
 	case "docx", "word":
 		return NewDocxExporter(f.htmlCleaner), nil
+	case "html", "htm":
+		return NewHTMLExporter(f.htmlCleaner), nil
 	default:
 		return nil, fmt.Errorf("unsupported export format: %s", format)
 	}
@ -59,5 +61,5 @@ func (f *Factory) CreateExporter(format string) (interfaces.Exporter, error) {
 // Returns:
 //   - A string slice containing all supported format names
 func (f *Factory) GetSupportedFormats() []string {
-	return []string{"markdown", "md", "docx", "word"}
+	return []string{"markdown", "md", "docx", "word", "html", "htm"}
 }
--- a/internal/exporters/factory_test.go
+++ b/internal/exporters/factory_test.go
@ -0,0 +1,478 @@
+// Package exporters_test provides tests for the exporter factory.
+package exporters
+
+import (
+	"reflect"
+	"sort"
+	"strings"
+	"testing"
+
+	"github.com/kjanat/articulate-parser/internal/services"
+)
+
+// TestNewFactory tests the NewFactory constructor.
+func TestNewFactory(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	if factory == nil {
+		t.Fatal("NewFactory() returned nil")
+	}
+
+	// Type assertion to check internal structure
+	factoryImpl, ok := factory.(*Factory)
+	if !ok {
+		t.Fatal("NewFactory() returned wrong type")
+	}
+
+	if factoryImpl.htmlCleaner == nil {
+		t.Error("htmlCleaner should not be nil")
+	}
+}
+
+// TestFactory_CreateExporter tests the CreateExporter method for all supported formats.
+func TestFactory_CreateExporter(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	testCases := []struct {
+		name           string
+		format         string
+		expectedType   string
+		expectedFormat string
+		shouldError    bool
+	}{
+		{
+			name:           "markdown format",
+			format:         "markdown",
+			expectedType:   "*exporters.MarkdownExporter",
+			expectedFormat: "markdown",
+			shouldError:    false,
+		},
+		{
+			name:           "md format alias",
+			format:         "md",
+			expectedType:   "*exporters.MarkdownExporter",
+			expectedFormat: "markdown",
+			shouldError:    false,
+		},
+		{
+			name:           "docx format",
+			format:         "docx",
+			expectedType:   "*exporters.DocxExporter",
+			expectedFormat: "docx",
+			shouldError:    false,
+		},
+		{
+			name:           "word format alias",
+			format:         "word",
+			expectedType:   "*exporters.DocxExporter",
+			expectedFormat: "docx",
+			shouldError:    false,
+		},
+		{
+			name:           "html format",
+			format:         "html",
+			expectedType:   "*exporters.HTMLExporter",
+			expectedFormat: "html",
+			shouldError:    false,
+		},
+		{
+			name:           "htm format alias",
+			format:         "htm",
+			expectedType:   "*exporters.HTMLExporter",
+			expectedFormat: "html",
+			shouldError:    false,
+		},
+		{
+			name:        "unsupported format",
+			format:      "pdf",
+			shouldError: true,
+		},
+		{
+			name:        "empty format",
+			format:      "",
+			shouldError: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			exporter, err := factory.CreateExporter(tc.format)
+
+			if tc.shouldError {
+				if err == nil {
+					t.Errorf("Expected error for format '%s', but got nil", tc.format)
+				}
+				if exporter != nil {
+					t.Errorf("Expected nil exporter for unsupported format '%s'", tc.format)
+				}
+				return
+			}
+
+			if err != nil {
+				t.Fatalf("Unexpected error creating exporter for format '%s': %v", tc.format, err)
+			}
+
+			if exporter == nil {
+				t.Fatalf("CreateExporter returned nil for supported format '%s'", tc.format)
+			}
+
+			// Check type
+			exporterType := reflect.TypeOf(exporter).String()
+			if exporterType != tc.expectedType {
+				t.Errorf("Expected exporter type '%s' for format '%s', got '%s'", tc.expectedType, tc.format, exporterType)
+			}
+
+			// Check supported format
+			supportedFormat := exporter.GetSupportedFormat()
+			if supportedFormat != tc.expectedFormat {
+				t.Errorf("Expected supported format '%s' for format '%s', got '%s'", tc.expectedFormat, tc.format, supportedFormat)
+			}
+		})
+	}
+}
+
+// TestFactory_CreateExporter_CaseInsensitive tests that format strings are case-insensitive.
+func TestFactory_CreateExporter_CaseInsensitive(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	testCases := []struct {
+		format         string
+		expectedFormat string
+	}{
+		{"MARKDOWN", "markdown"},
+		{"Markdown", "markdown"},
+		{"MarkDown", "markdown"},
+		{"MD", "markdown"},
+		{"Md", "markdown"},
+		{"DOCX", "docx"},
+		{"Docx", "docx"},
+		{"DocX", "docx"},
+		{"WORD", "docx"},
+		{"Word", "docx"},
+		{"WoRd", "docx"},
+		{"HTML", "html"},
+		{"Html", "html"},
+		{"HtMl", "html"},
+		{"HTM", "html"},
+		{"Htm", "html"},
+		{"HtM", "html"},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.format, func(t *testing.T) {
+			exporter, err := factory.CreateExporter(tc.format)
+
+			if err != nil {
+				t.Fatalf("Unexpected error for format '%s': %v", tc.format, err)
+			}
+
+			if exporter == nil {
+				t.Fatalf("CreateExporter returned nil for format '%s'", tc.format)
+			}
+
+			supportedFormat := exporter.GetSupportedFormat()
+			if supportedFormat != tc.expectedFormat {
+				t.Errorf("Expected supported format '%s' for format '%s', got '%s'", tc.expectedFormat, tc.format, supportedFormat)
+			}
+		})
+	}
+}
+
+// TestFactory_CreateExporter_ErrorMessages tests error messages for unsupported formats.
+func TestFactory_CreateExporter_ErrorMessages(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	testCases := []string{
+		"pdf",
+		"txt",
+		"json",
+		"xml",
+		"unknown",
+		"123",
+		"markdown-invalid",
+	}
+
+	for _, format := range testCases {
+		t.Run(format, func(t *testing.T) {
+			exporter, err := factory.CreateExporter(format)
+
+			if err == nil {
+				t.Errorf("Expected error for unsupported format '%s', got nil", format)
+			}
+
+			if exporter != nil {
+				t.Errorf("Expected nil exporter for unsupported format '%s', got %v", format, exporter)
+			}
+
+			// Check error message contains the format
+			if err != nil && !strings.Contains(err.Error(), format) {
+				t.Errorf("Error message should contain the unsupported format '%s', got: %s", format, err.Error())
+			}
+
+			// Check error message has expected prefix
+			if err != nil && !strings.Contains(err.Error(), "unsupported export format") {
+				t.Errorf("Error message should contain 'unsupported export format', got: %s", err.Error())
+			}
+		})
+	}
+}
+
+// TestFactory_GetSupportedFormats tests the GetSupportedFormats method.
+func TestFactory_GetSupportedFormats(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	formats := factory.GetSupportedFormats()
+
+	if formats == nil {
+		t.Fatal("GetSupportedFormats() returned nil")
+	}
+
+	expected := []string{"markdown", "md", "docx", "word", "html", "htm"}
+
+	// Sort both slices for comparison
+	sort.Strings(formats)
+	sort.Strings(expected)
+
+	if !reflect.DeepEqual(formats, expected) {
+		t.Errorf("Expected formats %v, got %v", expected, formats)
+	}
+
+	// Verify all returned formats can create exporters
+	for _, format := range formats {
+		exporter, err := factory.CreateExporter(format)
+		if err != nil {
+			t.Errorf("Format '%s' from GetSupportedFormats() should be creatable, got error: %v", format, err)
+		}
+		if exporter == nil {
+			t.Errorf("Format '%s' from GetSupportedFormats() should create non-nil exporter", format)
+		}
+	}
+}
+
+// TestFactory_GetSupportedFormats_Immutable tests that the returned slice is safe to modify.
+func TestFactory_GetSupportedFormats_Immutable(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	// Get formats twice
+	formats1 := factory.GetSupportedFormats()
+	formats2 := factory.GetSupportedFormats()
+
+	// Modify first slice
+	if len(formats1) > 0 {
+		formats1[0] = "modified"
+	}
+
+	// Check that second call returns unmodified data
+	if len(formats2) > 0 && formats2[0] == "modified" {
+		t.Error("GetSupportedFormats() should return independent slices")
+	}
+
+	// Verify original functionality still works
+	formats3 := factory.GetSupportedFormats()
+	if len(formats3) == 0 {
+		t.Error("GetSupportedFormats() should still return formats after modification")
+	}
+}
+
+// TestFactory_ExporterTypes tests that created exporters are of correct types.
+func TestFactory_ExporterTypes(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	// Test markdown exporter
+	markdownExporter, err := factory.CreateExporter("markdown")
+	if err != nil {
+		t.Fatalf("Failed to create markdown exporter: %v", err)
+	}
+
+	if _, ok := markdownExporter.(*MarkdownExporter); !ok {
+		t.Error("Markdown exporter should be of type *MarkdownExporter")
+	}
+
+	// Test docx exporter
+	docxExporter, err := factory.CreateExporter("docx")
+	if err != nil {
+		t.Fatalf("Failed to create docx exporter: %v", err)
+	}
+
+	if _, ok := docxExporter.(*DocxExporter); !ok {
+		t.Error("DOCX exporter should be of type *DocxExporter")
+	}
+}
+
+// TestFactory_HTMLCleanerPropagation tests that HTMLCleaner is properly passed to exporters.
+func TestFactory_HTMLCleanerPropagation(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	// Test with markdown exporter
+	markdownExporter, err := factory.CreateExporter("markdown")
+	if err != nil {
+		t.Fatalf("Failed to create markdown exporter: %v", err)
+	}
+
+	markdownImpl, ok := markdownExporter.(*MarkdownExporter)
+	if !ok {
+		t.Fatal("Failed to cast to MarkdownExporter")
+	}
+
+	if markdownImpl.htmlCleaner == nil {
+		t.Error("HTMLCleaner should be propagated to MarkdownExporter")
+	}
+
+	// Test with docx exporter
+	docxExporter, err := factory.CreateExporter("docx")
+	if err != nil {
+		t.Fatalf("Failed to create docx exporter: %v", err)
+	}
+
+	docxImpl, ok := docxExporter.(*DocxExporter)
+	if !ok {
+		t.Fatal("Failed to cast to DocxExporter")
+	}
+
+	if docxImpl.htmlCleaner == nil {
+		t.Error("HTMLCleaner should be propagated to DocxExporter")
+	}
+
+	// Test with html exporter
+	htmlExporter, err := factory.CreateExporter("html")
+	if err != nil {
+		t.Fatalf("Failed to create html exporter: %v", err)
+	}
+
+	htmlImpl, ok := htmlExporter.(*HTMLExporter)
+	if !ok {
+		t.Fatal("Failed to cast to HTMLExporter")
+	}
+
+	if htmlImpl.htmlCleaner == nil {
+		t.Error("HTMLCleaner should be propagated to HTMLExporter")
+	}
+}
+
+// TestFactory_MultipleExporterCreation tests creating multiple exporters of same type.
+func TestFactory_MultipleExporterCreation(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	// Create multiple markdown exporters
+	exporter1, err := factory.CreateExporter("markdown")
+	if err != nil {
+		t.Fatalf("Failed to create first markdown exporter: %v", err)
+	}
+
+	exporter2, err := factory.CreateExporter("md")
+	if err != nil {
+		t.Fatalf("Failed to create second markdown exporter: %v", err)
+	}
+
+	// They should be different instances
+	if exporter1 == exporter2 {
+		t.Error("Factory should create independent exporter instances")
+	}
+
+	// But both should be MarkdownExporter type
+	if _, ok := exporter1.(*MarkdownExporter); !ok {
+		t.Error("First exporter should be MarkdownExporter")
+	}
+
+	if _, ok := exporter2.(*MarkdownExporter); !ok {
+		t.Error("Second exporter should be MarkdownExporter")
+	}
+}
+
+// TestFactory_WithNilHTMLCleaner tests factory behavior with nil HTMLCleaner.
+func TestFactory_WithNilHTMLCleaner(t *testing.T) {
+	// This tests edge case - should not panic but behavior may vary
+	defer func() {
+		if r := recover(); r != nil {
+			t.Errorf("Factory should handle nil HTMLCleaner gracefully, but panicked: %v", r)
+		}
+	}()
+
+	factory := NewFactory(nil)
+
+	if factory == nil {
+		t.Fatal("NewFactory(nil) returned nil")
+	}
+
+	// Try to create an exporter - this might fail or succeed depending on implementation
+	_, err := factory.CreateExporter("markdown")
+
+	// We don't assert on the error since nil HTMLCleaner handling is implementation-dependent
+	// The important thing is that it doesn't panic
+	_ = err
+}
+
+// TestFactory_FormatNormalization tests that format strings are properly normalized.
+func TestFactory_FormatNormalization(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	// Test formats with extra whitespace
+	testCases := []struct {
+		input    string
+		expected string
+	}{
+		{"markdown", "markdown"},
+		{"MARKDOWN", "markdown"},
+		{"Markdown", "markdown"},
+		{"docx", "docx"},
+		{"DOCX", "docx"},
+		{"Docx", "docx"},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.input, func(t *testing.T) {
+			exporter, err := factory.CreateExporter(tc.input)
+			if err != nil {
+				t.Fatalf("Failed to create exporter for '%s': %v", tc.input, err)
+			}
+
+			format := exporter.GetSupportedFormat()
+			if format != tc.expected {
+				t.Errorf("Expected format '%s' for input '%s', got '%s'", tc.expected, tc.input, format)
+			}
+		})
+	}
+}
+
+// BenchmarkFactory_CreateExporter benchmarks the CreateExporter method.
+func BenchmarkFactory_CreateExporter(b *testing.B) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, _ = factory.CreateExporter("markdown")
+	}
+}
+
+// BenchmarkFactory_CreateExporter_Docx benchmarks creating DOCX exporters.
+func BenchmarkFactory_CreateExporter_Docx(b *testing.B) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, _ = factory.CreateExporter("docx")
+	}
+}
+
+// BenchmarkFactory_GetSupportedFormats benchmarks the GetSupportedFormats method.
+func BenchmarkFactory_GetSupportedFormats(b *testing.B) {
+	htmlCleaner := services.NewHTMLCleaner()
+	factory := NewFactory(htmlCleaner)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = factory.GetSupportedFormats()
+	}
+}
--- a/internal/exporters/html.go
+++ b/internal/exporters/html.go
@ -0,0 +1,476 @@
+// Package exporters provides implementations of the Exporter interface
+// for converting Articulate Rise courses into various file formats.
+package exporters
+
+import (
+	"bytes"
+	"fmt"
+	"html"
+	"os"
+	"strings"
+
+	"github.com/kjanat/articulate-parser/internal/interfaces"
+	"github.com/kjanat/articulate-parser/internal/models"
+	"github.com/kjanat/articulate-parser/internal/services"
+)
+
+// HTMLExporter implements the Exporter interface for HTML format.
+// It converts Articulate Rise course data into a structured HTML document.
+type HTMLExporter struct {
+	// htmlCleaner is used to convert HTML content to plain text when needed
+	htmlCleaner *services.HTMLCleaner
+}
+
+// NewHTMLExporter creates a new HTMLExporter instance.
+// It takes an HTMLCleaner to handle HTML content conversion when plain text is needed.
+//
+// Parameters:
+//   - htmlCleaner: Service for cleaning HTML content in course data
+//
+// Returns:
+//   - An implementation of the Exporter interface for HTML format
+func NewHTMLExporter(htmlCleaner *services.HTMLCleaner) interfaces.Exporter {
+	return &HTMLExporter{
+		htmlCleaner: htmlCleaner,
+	}
+}
+
+// Export exports a course to HTML format.
+// It generates a structured HTML document from the course data
+// and writes it to the specified output path.
+//
+// Parameters:
+//   - course: The course data model to export
+//   - outputPath: The file path where the HTML content will be written
+//
+// Returns:
+//   - An error if writing to the output file fails
+func (e *HTMLExporter) Export(course *models.Course, outputPath string) error {
+	var buf bytes.Buffer
+
+	// Write HTML document structure
+	buf.WriteString("<!DOCTYPE html>\n")
+	buf.WriteString("<html lang=\"en\">\n")
+	buf.WriteString("<head>\n")
+	buf.WriteString("    <meta charset=\"UTF-8\">\n")
+	buf.WriteString("    <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n")
+	buf.WriteString(fmt.Sprintf("    <title>%s</title>\n", html.EscapeString(course.Course.Title)))
+	buf.WriteString("    <style>\n")
+	buf.WriteString(e.getDefaultCSS())
+	buf.WriteString("    </style>\n")
+	buf.WriteString("</head>\n")
+	buf.WriteString("<body>\n")
+
+	// Write course header
+	buf.WriteString(fmt.Sprintf("    <header>\n        <h1>%s</h1>\n", html.EscapeString(course.Course.Title)))
+
+	if course.Course.Description != "" {
+		buf.WriteString(fmt.Sprintf("        <div class=\"course-description\">%s</div>\n", course.Course.Description))
+	}
+	buf.WriteString("    </header>\n\n")
+
+	// Add metadata section
+	buf.WriteString("    <section class=\"course-info\">\n")
+	buf.WriteString("        <h2>Course Information</h2>\n")
+	buf.WriteString("        <ul>\n")
+	buf.WriteString(fmt.Sprintf("            <li><strong>Course ID:</strong> %s</li>\n", html.EscapeString(course.Course.ID)))
+	buf.WriteString(fmt.Sprintf("            <li><strong>Share ID:</strong> %s</li>\n", html.EscapeString(course.ShareID)))
+	buf.WriteString(fmt.Sprintf("            <li><strong>Navigation Mode:</strong> %s</li>\n", html.EscapeString(course.Course.NavigationMode)))
+	if course.Course.ExportSettings != nil {
+		buf.WriteString(fmt.Sprintf("            <li><strong>Export Format:</strong> %s</li>\n", html.EscapeString(course.Course.ExportSettings.Format)))
+	}
+	buf.WriteString("        </ul>\n")
+	buf.WriteString("    </section>\n\n")
+
+	// Process lessons
+	lessonCounter := 0
+	for _, lesson := range course.Course.Lessons {
+		if lesson.Type == "section" {
+			buf.WriteString(fmt.Sprintf("    <section class=\"course-section\">\n        <h2>%s</h2>\n    </section>\n\n", html.EscapeString(lesson.Title)))
+			continue
+		}
+
+		lessonCounter++
+		buf.WriteString(fmt.Sprintf("    <section class=\"lesson\">\n        <h3>Lesson %d: %s</h3>\n", lessonCounter, html.EscapeString(lesson.Title)))
+
+		if lesson.Description != "" {
+			buf.WriteString(fmt.Sprintf("        <div class=\"lesson-description\">%s</div>\n", lesson.Description))
+		}
+
+		// Process lesson items
+		for _, item := range lesson.Items {
+			e.processItemToHTML(&buf, item)
+		}
+
+		buf.WriteString("    </section>\n\n")
+	}
+
+	buf.WriteString("</body>\n")
+	buf.WriteString("</html>\n")
+
+	return os.WriteFile(outputPath, buf.Bytes(), 0644)
+}
+
+// GetSupportedFormat returns the format name this exporter supports
+// It indicates the file format that the HTMLExporter can generate.
+//
+// Returns:
+//   - A string representing the supported format ("html")
+func (e *HTMLExporter) GetSupportedFormat() string {
+	return "html"
+}
+
+// getDefaultCSS returns basic CSS styling for the HTML document
+func (e *HTMLExporter) getDefaultCSS() string {
+	return `
+        body {
+            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
+            line-height: 1.6;
+            color: #333;
+            max-width: 800px;
+            margin: 0 auto;
+            padding: 20px;
+            background-color: #f9f9f9;
+        }
+        header {
+            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+            color: white;
+            padding: 2rem;
+            border-radius: 10px;
+            margin-bottom: 2rem;
+            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
+        }
+        header h1 {
+            margin: 0;
+            font-size: 2.5rem;
+            font-weight: 300;
+        }
+        .course-description {
+            margin-top: 1rem;
+            font-size: 1.1rem;
+            opacity: 0.9;
+        }
+        .course-info {
+            background: white;
+            padding: 1.5rem;
+            border-radius: 8px;
+            margin-bottom: 2rem;
+            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
+        }
+        .course-info h2 {
+            margin-top: 0;
+            color: #4a5568;
+            border-bottom: 2px solid #e2e8f0;
+            padding-bottom: 0.5rem;
+        }
+        .course-info ul {
+            list-style: none;
+            padding: 0;
+        }
+        .course-info li {
+            margin: 0.5rem 0;
+            padding: 0.5rem;
+            background: #f7fafc;
+            border-radius: 4px;
+        }
+        .course-section {
+            background: #4299e1;
+            color: white;
+            padding: 1.5rem;
+            border-radius: 8px;
+            margin: 2rem 0;
+            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
+        }
+        .course-section h2 {
+            margin: 0;
+            font-weight: 400;
+        }
+        .lesson {
+            background: white;
+            padding: 2rem;
+            border-radius: 8px;
+            margin: 2rem 0;
+            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
+            border-left: 4px solid #4299e1;
+        }
+        .lesson h3 {
+            margin-top: 0;
+            color: #2d3748;
+            font-size: 1.5rem;
+        }
+        .lesson-description {
+            margin: 1rem 0;
+            padding: 1rem;
+            background: #f7fafc;
+            border-radius: 4px;
+            border-left: 3px solid #4299e1;
+        }
+        .item {
+            margin: 1.5rem 0;
+            padding: 1rem;
+            border-radius: 6px;
+            background: #fafafa;
+            border: 1px solid #e2e8f0;
+        }
+        .item h4 {
+            margin-top: 0;
+            color: #4a5568;
+            font-size: 1.2rem;
+            text-transform: capitalize;
+        }
+        .text-item {
+            background: #f0fff4;
+            border-left: 3px solid #48bb78;
+        }
+        .list-item {
+            background: #fffaf0;
+            border-left: 3px solid #ed8936;
+        }
+        .knowledge-check {
+            background: #e6fffa;
+            border-left: 3px solid #38b2ac;
+        }
+        .multimedia-item {
+            background: #faf5ff;
+            border-left: 3px solid #9f7aea;
+        }
+        .interactive-item {
+            background: #fff5f5;
+            border-left: 3px solid #f56565;
+        }
+        .unknown-item {
+            background: #f7fafc;
+            border-left: 3px solid #a0aec0;
+        }
+        .answers {
+            margin: 1rem 0;
+        }
+        .answers h5 {
+            margin: 0.5rem 0;
+            color: #4a5568;
+        }
+        .answers ol {
+            margin: 0.5rem 0;
+            padding-left: 1.5rem;
+        }
+        .answers li {
+            margin: 0.3rem 0;
+            padding: 0.3rem;
+        }
+        .correct-answer {
+            background: #c6f6d5;
+            border-radius: 3px;
+            font-weight: bold;
+        }
+        .correct-answer::after {
+            content: " ✓";
+            color: #38a169;
+        }
+        .feedback {
+            margin: 1rem 0;
+            padding: 1rem;
+            background: #edf2f7;
+            border-radius: 4px;
+            border-left: 3px solid #4299e1;
+            font-style: italic;
+        }
+        .media-info {
+            background: #edf2f7;
+            padding: 1rem;
+            border-radius: 4px;
+            margin: 0.5rem 0;
+        }
+        .media-info strong {
+            color: #4a5568;
+        }
+        hr {
+            border: none;
+            height: 2px;
+            background: linear-gradient(to right, #667eea, #764ba2);
+            margin: 2rem 0;
+            border-radius: 1px;
+        }
+        ul {
+            padding-left: 1.5rem;
+        }
+        li {
+            margin: 0.5rem 0;
+        }
+    `
+}
+
+// processItemToHTML converts a course item into HTML format
+// and appends it to the provided buffer. It handles different item types
+// with appropriate HTML formatting.
+//
+// Parameters:
+//   - buf: The buffer to write the HTML content to
+//   - item: The course item to process
+func (e *HTMLExporter) processItemToHTML(buf *bytes.Buffer, item models.Item) {
+	switch strings.ToLower(item.Type) {
+	case "text":
+		e.processTextItem(buf, item)
+	case "list":
+		e.processListItem(buf, item)
+	case "knowledgecheck":
+		e.processKnowledgeCheckItem(buf, item)
+	case "multimedia":
+		e.processMultimediaItem(buf, item)
+	case "image":
+		e.processImageItem(buf, item)
+	case "interactive":
+		e.processInteractiveItem(buf, item)
+	case "divider":
+		e.processDividerItem(buf)
+	default:
+		e.processUnknownItem(buf, item)
+	}
+}
+
+// processTextItem handles text content with headings and paragraphs
+func (e *HTMLExporter) processTextItem(buf *bytes.Buffer, item models.Item) {
+	buf.WriteString("        <div class=\"item text-item\">\n")
+	buf.WriteString("            <h4>Text Content</h4>\n")
+	for _, subItem := range item.Items {
+		if subItem.Heading != "" {
+			buf.WriteString(fmt.Sprintf("            <h5>%s</h5>\n", subItem.Heading))
+		}
+		if subItem.Paragraph != "" {
+			buf.WriteString(fmt.Sprintf("            <div>%s</div>\n", subItem.Paragraph))
+		}
+	}
+	buf.WriteString("        </div>\n\n")
+}
+
+// processListItem handles list content
+func (e *HTMLExporter) processListItem(buf *bytes.Buffer, item models.Item) {
+	buf.WriteString("        <div class=\"item list-item\">\n")
+	buf.WriteString("            <h4>List</h4>\n")
+	buf.WriteString("            <ul>\n")
+	for _, subItem := range item.Items {
+		if subItem.Paragraph != "" {
+			cleanText := e.htmlCleaner.CleanHTML(subItem.Paragraph)
+			buf.WriteString(fmt.Sprintf("                <li>%s</li>\n", html.EscapeString(cleanText)))
+		}
+	}
+	buf.WriteString("            </ul>\n")
+	buf.WriteString("        </div>\n\n")
+}
+
+// processKnowledgeCheckItem handles quiz questions and answers
+func (e *HTMLExporter) processKnowledgeCheckItem(buf *bytes.Buffer, item models.Item) {
+	buf.WriteString("        <div class=\"item knowledge-check\">\n")
+	buf.WriteString("            <h4>Knowledge Check</h4>\n")
+	for _, subItem := range item.Items {
+		if subItem.Title != "" {
+			buf.WriteString(fmt.Sprintf("            <p><strong>Question:</strong> %s</p>\n", subItem.Title))
+		}
+		if len(subItem.Answers) > 0 {
+			e.processAnswers(buf, subItem.Answers)
+		}
+		if subItem.Feedback != "" {
+			buf.WriteString(fmt.Sprintf("            <div class=\"feedback\"><strong>Feedback:</strong> %s</div>\n", subItem.Feedback))
+		}
+	}
+	buf.WriteString("        </div>\n\n")
+}
+
+// processMultimediaItem handles multimedia content like videos
+func (e *HTMLExporter) processMultimediaItem(buf *bytes.Buffer, item models.Item) {
+	buf.WriteString("        <div class=\"item multimedia-item\">\n")
+	buf.WriteString("            <h4>Media Content</h4>\n")
+	for _, subItem := range item.Items {
+		if subItem.Title != "" {
+			buf.WriteString(fmt.Sprintf("            <h5>%s</h5>\n", subItem.Title))
+		}
+		if subItem.Media != nil {
+			if subItem.Media.Video != nil {
+				buf.WriteString("            <div class=\"media-info\">\n")
+				buf.WriteString(fmt.Sprintf("                <p><strong>Video:</strong> %s</p>\n", html.EscapeString(subItem.Media.Video.OriginalUrl)))
+				if subItem.Media.Video.Duration > 0 {
+					buf.WriteString(fmt.Sprintf("                <p><strong>Duration:</strong> %d seconds</p>\n", subItem.Media.Video.Duration))
+				}
+				buf.WriteString("            </div>\n")
+			}
+		}
+		if subItem.Caption != "" {
+			buf.WriteString(fmt.Sprintf("            <div><em>%s</em></div>\n", subItem.Caption))
+		}
+	}
+	buf.WriteString("        </div>\n\n")
+}
+
+// processImageItem handles image content
+func (e *HTMLExporter) processImageItem(buf *bytes.Buffer, item models.Item) {
+	buf.WriteString("        <div class=\"item multimedia-item\">\n")
+	buf.WriteString("            <h4>Image</h4>\n")
+	for _, subItem := range item.Items {
+		if subItem.Media != nil && subItem.Media.Image != nil {
+			buf.WriteString("            <div class=\"media-info\">\n")
+			buf.WriteString(fmt.Sprintf("                <p><strong>Image:</strong> %s</p>\n", html.EscapeString(subItem.Media.Image.OriginalUrl)))
+			buf.WriteString("            </div>\n")
+		}
+		if subItem.Caption != "" {
+			buf.WriteString(fmt.Sprintf("            <div><em>%s</em></div>\n", subItem.Caption))
+		}
+	}
+	buf.WriteString("        </div>\n\n")
+}
+
+// processInteractiveItem handles interactive content
+func (e *HTMLExporter) processInteractiveItem(buf *bytes.Buffer, item models.Item) {
+	buf.WriteString("        <div class=\"item interactive-item\">\n")
+	buf.WriteString("            <h4>Interactive Content</h4>\n")
+	for _, subItem := range item.Items {
+		if subItem.Title != "" {
+			buf.WriteString(fmt.Sprintf("            <p><strong>%s</strong></p>\n", subItem.Title))
+		}
+		if subItem.Paragraph != "" {
+			buf.WriteString(fmt.Sprintf("            <div>%s</div>\n", subItem.Paragraph))
+		}
+	}
+	buf.WriteString("        </div>\n\n")
+}
+
+// processDividerItem handles divider elements
+func (e *HTMLExporter) processDividerItem(buf *bytes.Buffer) {
+	buf.WriteString("        <hr>\n\n")
+}
+
+// processUnknownItem handles unknown or unsupported item types
+func (e *HTMLExporter) processUnknownItem(buf *bytes.Buffer, item models.Item) {
+	if len(item.Items) > 0 {
+		buf.WriteString("        <div class=\"item unknown-item\">\n")
+		buf.WriteString(fmt.Sprintf("            <h4>%s Content</h4>\n", strings.Title(item.Type)))
+		for _, subItem := range item.Items {
+			e.processGenericSubItem(buf, subItem)
+		}
+		buf.WriteString("        </div>\n\n")
+	}
+}
+
+// processGenericSubItem processes sub-items for unknown types
+func (e *HTMLExporter) processGenericSubItem(buf *bytes.Buffer, subItem models.SubItem) {
+	if subItem.Title != "" {
+		buf.WriteString(fmt.Sprintf("            <p><strong>%s</strong></p>\n", subItem.Title))
+	}
+	if subItem.Paragraph != "" {
+		buf.WriteString(fmt.Sprintf("            <div>%s</div>\n", subItem.Paragraph))
+	}
+}
+
+// processAnswers processes answer choices for quiz questions
+func (e *HTMLExporter) processAnswers(buf *bytes.Buffer, answers []models.Answer) {
+	buf.WriteString("            <div class=\"answers\">\n")
+	buf.WriteString("                <h5>Answers:</h5>\n")
+	buf.WriteString("                <ol>\n")
+	for _, answer := range answers {
+		cssClass := ""
+		if answer.Correct {
+			cssClass = " class=\"correct-answer\""
+		}
+		buf.WriteString(fmt.Sprintf("                    <li%s>%s</li>\n", cssClass, html.EscapeString(answer.Title)))
+	}
+	buf.WriteString("                </ol>\n")
+	buf.WriteString("            </div>\n")
+}
--- a/internal/exporters/html_test.go
+++ b/internal/exporters/html_test.go
@ -0,0 +1,927 @@
+// Package exporters_test provides tests for the html exporter.
+package exporters
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/kjanat/articulate-parser/internal/models"
+	"github.com/kjanat/articulate-parser/internal/services"
+)
+
+// TestNewHTMLExporter tests the NewHTMLExporter constructor.
+func TestNewHTMLExporter(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewHTMLExporter(htmlCleaner)
+
+	if exporter == nil {
+		t.Fatal("NewHTMLExporter() returned nil")
+	}
+
+	// Type assertion to check internal structure
+	htmlExporter, ok := exporter.(*HTMLExporter)
+	if !ok {
+		t.Fatal("NewHTMLExporter() returned wrong type")
+	}
+
+	if htmlExporter.htmlCleaner == nil {
+		t.Error("htmlCleaner should not be nil")
+	}
+}
+
+// TestHTMLExporter_GetSupportedFormat tests the GetSupportedFormat method.
+func TestHTMLExporter_GetSupportedFormat(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewHTMLExporter(htmlCleaner)
+
+	expected := "html"
+	result := exporter.GetSupportedFormat()
+
+	if result != expected {
+		t.Errorf("Expected format '%s', got '%s'", expected, result)
+	}
+}
+
+// TestHTMLExporter_Export tests the Export method.
+func TestHTMLExporter_Export(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewHTMLExporter(htmlCleaner)
+
+	// Create test course
+	testCourse := createTestCourseForHTML()
+
+	// Create temporary directory and file
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "test-course.html")
+
+	// Test successful export
+	err := exporter.Export(testCourse, outputPath)
+	if err != nil {
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Check that file was created
+	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+		t.Fatal("Output file was not created")
+	}
+
+	// Read and verify content
+	content, err := os.ReadFile(outputPath)
+	if err != nil {
+		t.Fatalf("Failed to read output file: %v", err)
+	}
+
+	contentStr := string(content)
+
+	// Verify HTML structure
+	if !strings.Contains(contentStr, "<!DOCTYPE html>") {
+		t.Error("Output should contain HTML doctype")
+	}
+
+	if !strings.Contains(contentStr, "<html lang=\"en\">") {
+		t.Error("Output should contain HTML tag with lang attribute")
+	}
+
+	if !strings.Contains(contentStr, "<title>Test Course</title>") {
+		t.Error("Output should contain course title in head")
+	}
+
+	// Verify main course title
+	if !strings.Contains(contentStr, "<h1>Test Course</h1>") {
+		t.Error("Output should contain course title as main heading")
+	}
+
+	// Verify course information section
+	if !strings.Contains(contentStr, "Course Information") {
+		t.Error("Output should contain course information section")
+	}
+
+	// Verify course metadata
+	if !strings.Contains(contentStr, "Course ID") {
+		t.Error("Output should contain course ID")
+	}
+
+	if !strings.Contains(contentStr, "Share ID") {
+		t.Error("Output should contain share ID")
+	}
+
+	// Verify lesson content
+	if !strings.Contains(contentStr, "Lesson 1: Test Lesson") {
+		t.Error("Output should contain lesson heading")
+	}
+
+	// Verify CSS is included
+	if !strings.Contains(contentStr, "<style>") {
+		t.Error("Output should contain CSS styles")
+	}
+
+	if !strings.Contains(contentStr, "font-family") {
+		t.Error("Output should contain CSS font-family")
+	}
+}
+
+// TestHTMLExporter_Export_InvalidPath tests export with invalid output path.
+func TestHTMLExporter_Export_InvalidPath(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewHTMLExporter(htmlCleaner)
+
+	testCourse := createTestCourseForHTML()
+
+	// Try to export to invalid path (non-existent directory)
+	invalidPath := "/non/existent/path/test.html"
+	err := exporter.Export(testCourse, invalidPath)
+
+	if err == nil {
+		t.Error("Expected error for invalid output path, but got nil")
+	}
+}
+
+// TestHTMLExporter_ProcessTextItem tests the processTextItem method.
+func TestHTMLExporter_ProcessTextItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &HTMLExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "text",
+		Items: []models.SubItem{
+			{
+				Heading:   "<h1>Test Heading</h1>",
+				Paragraph: "<p>Test paragraph with <strong>bold</strong> text.</p>",
+			},
+			{
+				Paragraph: "<p>Another paragraph.</p>",
+			},
+		},
+	}
+
+	exporter.processTextItem(&buf, item)
+
+	result := buf.String()
+
+	if !strings.Contains(result, "text-item") {
+		t.Error("Should contain text-item CSS class")
+	}
+	if !strings.Contains(result, "Text Content") {
+		t.Error("Should contain text content heading")
+	}
+	if !strings.Contains(result, "<h1>Test Heading</h1>") {
+		t.Error("Should preserve HTML heading")
+	}
+	if !strings.Contains(result, "<strong>bold</strong>") {
+		t.Error("Should preserve HTML formatting in paragraph")
+	}
+}
+
+// TestHTMLExporter_ProcessListItem tests the processListItem method.
+func TestHTMLExporter_ProcessListItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &HTMLExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "list",
+		Items: []models.SubItem{
+			{Paragraph: "<p>First item</p>"},
+			{Paragraph: "<p>Second item with <em>emphasis</em></p>"},
+			{Paragraph: "<p>Third item</p>"},
+		},
+	}
+
+	exporter.processListItem(&buf, item)
+
+	result := buf.String()
+
+	if !strings.Contains(result, "list-item") {
+		t.Error("Should contain list-item CSS class")
+	}
+	if !strings.Contains(result, "<ul>") {
+		t.Error("Should contain unordered list")
+	}
+	if !strings.Contains(result, "<li>First item</li>") {
+		t.Error("Should contain first list item")
+	}
+	if !strings.Contains(result, "<li>Second item with emphasis</li>") {
+		t.Error("Should contain second list item with cleaned HTML")
+	}
+	if !strings.Contains(result, "<li>Third item</li>") {
+		t.Error("Should contain third list item")
+	}
+}
+
+// TestHTMLExporter_ProcessKnowledgeCheckItem tests the processKnowledgeCheckItem method.
+func TestHTMLExporter_ProcessKnowledgeCheckItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &HTMLExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "knowledgeCheck",
+		Items: []models.SubItem{
+			{
+				Title: "<p>What is the correct answer?</p>",
+				Answers: []models.Answer{
+					{Title: "Wrong answer", Correct: false},
+					{Title: "Correct answer", Correct: true},
+					{Title: "Another wrong answer", Correct: false},
+				},
+				Feedback: "<p>Great job! This is the feedback.</p>",
+			},
+		},
+	}
+
+	exporter.processKnowledgeCheckItem(&buf, item)
+
+	result := buf.String()
+
+	if !strings.Contains(result, "knowledge-check") {
+		t.Error("Should contain knowledge-check CSS class")
+	}
+	if !strings.Contains(result, "Knowledge Check") {
+		t.Error("Should contain knowledge check heading")
+	}
+	if !strings.Contains(result, "What is the correct answer?") {
+		t.Error("Should contain question text")
+	}
+	if !strings.Contains(result, "Wrong answer") {
+		t.Error("Should contain first answer")
+	}
+	if !strings.Contains(result, "correct-answer") {
+		t.Error("Should mark correct answer with CSS class")
+	}
+	if !strings.Contains(result, "Feedback") {
+		t.Error("Should contain feedback section")
+	}
+}
+
+// TestHTMLExporter_ProcessMultimediaItem tests the processMultimediaItem method.
+func TestHTMLExporter_ProcessMultimediaItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &HTMLExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "multimedia",
+		Items: []models.SubItem{
+			{
+				Title: "<p>Video Title</p>",
+				Media: &models.Media{
+					Video: &models.VideoMedia{
+						OriginalUrl: "https://example.com/video.mp4",
+						Duration:    120,
+					},
+				},
+				Caption: "<p>Video caption</p>",
+			},
+		},
+	}
+
+	exporter.processMultimediaItem(&buf, item)
+
+	result := buf.String()
+
+	if !strings.Contains(result, "multimedia-item") {
+		t.Error("Should contain multimedia-item CSS class")
+	}
+	if !strings.Contains(result, "Media Content") {
+		t.Error("Should contain media content heading")
+	}
+	if !strings.Contains(result, "Video Title") {
+		t.Error("Should contain video title")
+	}
+	if !strings.Contains(result, "https://example.com/video.mp4") {
+		t.Error("Should contain video URL")
+	}
+	if !strings.Contains(result, "120 seconds") {
+		t.Error("Should contain video duration")
+	}
+	if !strings.Contains(result, "Video caption") {
+		t.Error("Should contain video caption")
+	}
+}
+
+// TestHTMLExporter_ProcessImageItem tests the processImageItem method.
+func TestHTMLExporter_ProcessImageItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &HTMLExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "image",
+		Items: []models.SubItem{
+			{
+				Media: &models.Media{
+					Image: &models.ImageMedia{
+						OriginalUrl: "https://example.com/image.png",
+					},
+				},
+				Caption: "<p>Image caption</p>",
+			},
+		},
+	}
+
+	exporter.processImageItem(&buf, item)
+
+	result := buf.String()
+
+	if !strings.Contains(result, "multimedia-item") {
+		t.Error("Should contain multimedia-item CSS class")
+	}
+	if !strings.Contains(result, "Image") {
+		t.Error("Should contain image heading")
+	}
+	if !strings.Contains(result, "https://example.com/image.png") {
+		t.Error("Should contain image URL")
+	}
+	if !strings.Contains(result, "Image caption") {
+		t.Error("Should contain image caption")
+	}
+}
+
+// TestHTMLExporter_ProcessInteractiveItem tests the processInteractiveItem method.
+func TestHTMLExporter_ProcessInteractiveItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &HTMLExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "interactive",
+		Items: []models.SubItem{
+			{
+				Title:     "<p>Interactive element title</p>",
+				Paragraph: "<p>Interactive content description</p>",
+			},
+		},
+	}
+
+	exporter.processInteractiveItem(&buf, item)
+
+	result := buf.String()
+
+	if !strings.Contains(result, "interactive-item") {
+		t.Error("Should contain interactive-item CSS class")
+	}
+	if !strings.Contains(result, "Interactive Content") {
+		t.Error("Should contain interactive content heading")
+	}
+	if !strings.Contains(result, "Interactive element title") {
+		t.Error("Should contain interactive element title")
+	}
+	if !strings.Contains(result, "Interactive content description") {
+		t.Error("Should contain interactive content description")
+	}
+}
+
+// TestHTMLExporter_ProcessDividerItem tests the processDividerItem method.
+func TestHTMLExporter_ProcessDividerItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &HTMLExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	exporter.processDividerItem(&buf)
+
+	result := buf.String()
+	expected := "        <hr>\n\n"
+
+	if result != expected {
+		t.Errorf("Expected %q, got %q", expected, result)
+	}
+}
+
+// TestHTMLExporter_ProcessUnknownItem tests the processUnknownItem method.
+func TestHTMLExporter_ProcessUnknownItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &HTMLExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "unknown",
+		Items: []models.SubItem{
+			{
+				Title:     "<p>Unknown item title</p>",
+				Paragraph: "<p>Unknown item content</p>",
+			},
+		},
+	}
+
+	exporter.processUnknownItem(&buf, item)
+
+	result := buf.String()
+
+	if !strings.Contains(result, "unknown-item") {
+		t.Error("Should contain unknown-item CSS class")
+	}
+	if !strings.Contains(result, "Unknown Content") {
+		t.Error("Should contain unknown content heading")
+	}
+	if !strings.Contains(result, "Unknown item title") {
+		t.Error("Should contain unknown item title")
+	}
+	if !strings.Contains(result, "Unknown item content") {
+		t.Error("Should contain unknown item content")
+	}
+}
+
+// TestHTMLExporter_ProcessAnswers tests the processAnswers method.
+func TestHTMLExporter_ProcessAnswers(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &HTMLExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	answers := []models.Answer{
+		{Title: "Answer 1", Correct: false},
+		{Title: "Answer 2", Correct: true},
+		{Title: "Answer 3", Correct: false},
+	}
+
+	exporter.processAnswers(&buf, answers)
+
+	result := buf.String()
+
+	if !strings.Contains(result, "answers") {
+		t.Error("Should contain answers CSS class")
+	}
+	if !strings.Contains(result, "<h5>Answers:</h5>") {
+		t.Error("Should contain answers heading")
+	}
+	if !strings.Contains(result, "<ol>") {
+		t.Error("Should contain ordered list")
+	}
+	if !strings.Contains(result, "<li>Answer 1</li>") {
+		t.Error("Should contain first answer")
+	}
+	if !strings.Contains(result, "correct-answer") {
+		t.Error("Should mark correct answer with CSS class")
+	}
+	if !strings.Contains(result, "<li class=\"correct-answer\">Answer 2</li>") {
+		t.Error("Should mark correct answer properly")
+	}
+	if !strings.Contains(result, "<li>Answer 3</li>") {
+		t.Error("Should contain third answer")
+	}
+}
+
+// TestHTMLExporter_ProcessItemToHTML_AllTypes tests all item types.
+func TestHTMLExporter_ProcessItemToHTML_AllTypes(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &HTMLExporter{htmlCleaner: htmlCleaner}
+
+	tests := []struct {
+		name         string
+		itemType     string
+		expectedText string
+	}{
+		{
+			name:         "text item",
+			itemType:     "text",
+			expectedText: "Text Content",
+		},
+		{
+			name:         "list item",
+			itemType:     "list",
+			expectedText: "List",
+		},
+		{
+			name:         "knowledge check item",
+			itemType:     "knowledgeCheck",
+			expectedText: "Knowledge Check",
+		},
+		{
+			name:         "multimedia item",
+			itemType:     "multimedia",
+			expectedText: "Media Content",
+		},
+		{
+			name:         "image item",
+			itemType:     "image",
+			expectedText: "Image",
+		},
+		{
+			name:         "interactive item",
+			itemType:     "interactive",
+			expectedText: "Interactive Content",
+		},
+		{
+			name:         "divider item",
+			itemType:     "divider",
+			expectedText: "<hr>",
+		},
+		{
+			name:         "unknown item",
+			itemType:     "unknown",
+			expectedText: "Unknown Content",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var buf bytes.Buffer
+			item := models.Item{
+				Type: tt.itemType,
+				Items: []models.SubItem{
+					{Title: "Test title", Paragraph: "Test content"},
+				},
+			}
+
+			// Handle empty unknown items
+			if tt.itemType == "unknown" && tt.expectedText == "" {
+				item.Items = []models.SubItem{}
+			}
+
+			exporter.processItemToHTML(&buf, item)
+
+			result := buf.String()
+			if tt.expectedText != "" && !strings.Contains(result, tt.expectedText) {
+				t.Errorf("Expected content to contain: %q\nGot: %q", tt.expectedText, result)
+			}
+		})
+	}
+}
+
+// TestHTMLExporter_ComplexCourse tests export of a complex course structure.
+func TestHTMLExporter_ComplexCourse(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewHTMLExporter(htmlCleaner)
+
+	// Create complex test course
+	course := &models.Course{
+		ShareID: "complex-test-id",
+		Author:  "Test Author",
+		Course: models.CourseInfo{
+			ID:             "complex-course",
+			Title:          "Complex Test Course",
+			Description:    "<p>This is a <strong>complex</strong> course description.</p>",
+			NavigationMode: "menu",
+			ExportSettings: &models.ExportSettings{
+				Format: "scorm",
+			},
+			Lessons: []models.Lesson{
+				{
+					ID:    "section-1",
+					Title: "Course Section",
+					Type:  "section",
+				},
+				{
+					ID:          "lesson-1",
+					Title:       "Introduction Lesson",
+					Type:        "lesson",
+					Description: "<p>Introduction to the course</p>",
+					Items: []models.Item{
+						{
+							Type: "text",
+							Items: []models.SubItem{
+								{
+									Heading:   "<h2>Welcome</h2>",
+									Paragraph: "<p>Welcome to our course!</p>",
+								},
+							},
+						},
+						{
+							Type: "list",
+							Items: []models.SubItem{
+								{Paragraph: "<p>First objective</p>"},
+								{Paragraph: "<p>Second objective</p>"},
+							},
+						},
+						{
+							Type: "knowledgeCheck",
+							Items: []models.SubItem{
+								{
+									Title: "<p>What will you learn?</p>",
+									Answers: []models.Answer{
+										{Title: "Nothing", Correct: false},
+										{Title: "Everything", Correct: true},
+									},
+									Feedback: "<p>Great choice!</p>",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	// Create temporary output file
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "complex-course.html")
+
+	// Export course
+	err := exporter.Export(course, outputPath)
+	if err != nil {
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Read and verify content
+	content, err := os.ReadFile(outputPath)
+	if err != nil {
+		t.Fatalf("Failed to read output file: %v", err)
+	}
+
+	contentStr := string(content)
+
+	// Verify various elements are present
+	checks := []string{
+		"<title>Complex Test Course</title>",
+		"<h1>Complex Test Course</h1>",
+		"This is a <strong>complex</strong> course description.",
+		"Course Information",
+		"complex-course",
+		"complex-test-id",
+		"menu",
+		"scorm",
+		"Course Section",
+		"Lesson 1: Introduction Lesson",
+		"Introduction to the course",
+		"<h2>Welcome</h2>",
+		"Welcome to our course!",
+		"First objective",
+		"Second objective",
+		"Knowledge Check",
+		"What will you learn?",
+		"Nothing",
+		"Everything",
+		"correct-answer",
+		"Great choice!",
+	}
+
+	for _, check := range checks {
+		if !strings.Contains(contentStr, check) {
+			t.Errorf("Output should contain: %q", check)
+		}
+	}
+
+	// Verify HTML structure
+	structureChecks := []string{
+		"<!DOCTYPE html>",
+		"<html lang=\"en\">",
+		"<head>",
+		"<body>",
+		"</html>",
+		"<style>",
+		"font-family",
+	}
+
+	for _, check := range structureChecks {
+		if !strings.Contains(contentStr, check) {
+			t.Errorf("Output should contain HTML structure element: %q", check)
+		}
+	}
+}
+
+// TestHTMLExporter_EmptyCourse tests export of an empty course.
+func TestHTMLExporter_EmptyCourse(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewHTMLExporter(htmlCleaner)
+
+	// Create minimal course
+	course := &models.Course{
+		ShareID: "empty-id",
+		Course: models.CourseInfo{
+			ID:      "empty-course",
+			Title:   "Empty Course",
+			Lessons: []models.Lesson{},
+		},
+	}
+
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "empty-course.html")
+
+	err := exporter.Export(course, outputPath)
+	if err != nil {
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Verify file was created
+	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+		t.Fatal("Output file was not created")
+	}
+
+	// Read and verify basic structure
+	content, err := os.ReadFile(outputPath)
+	if err != nil {
+		t.Fatalf("Failed to read output file: %v", err)
+	}
+
+	contentStr := string(content)
+
+	// Verify basic HTML structure even for empty course
+	if !strings.Contains(contentStr, "<!DOCTYPE html>") {
+		t.Error("Output should contain HTML doctype")
+	}
+	if !strings.Contains(contentStr, "<title>Empty Course</title>") {
+		t.Error("Output should contain course title")
+	}
+	if !strings.Contains(contentStr, "<h1>Empty Course</h1>") {
+		t.Error("Output should contain course heading")
+	}
+}
+
+// TestHTMLExporter_HTMLCleaning tests that HTML content is properly handled.
+func TestHTMLExporter_HTMLCleaning(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewHTMLExporter(htmlCleaner)
+
+	// Create course with HTML content that needs cleaning in some places
+	course := &models.Course{
+		ShareID: "html-test-id",
+		Course: models.CourseInfo{
+			ID:          "html-test-course",
+			Title:       "HTML Test Course",
+			Description: "<p>Description with <script>alert('xss')</script> and <b>bold</b> text.</p>",
+			Lessons: []models.Lesson{
+				{
+					ID:          "lesson-1",
+					Title:       "Test Lesson",
+					Type:        "lesson",
+					Description: "<div>Lesson description with <span style='color:red'>styled</span> content.</div>",
+					Items: []models.Item{
+						{
+							Type: "text",
+							Items: []models.SubItem{
+								{
+									Heading:   "<h1>Heading with <em>emphasis</em> and &amp; entities</h1>",
+									Paragraph: "<p>Paragraph with &lt;code&gt; entities and <strong>formatting</strong>.</p>",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "html-test.html")
+
+	err := exporter.Export(course, outputPath)
+	if err != nil {
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Verify file was created (basic check that HTML handling didn't break export)
+	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+		t.Fatal("Output file was not created")
+	}
+
+	// Read content and verify some HTML is preserved (descriptions, headings, paragraphs)
+	// while list items are cleaned for safety
+	content, err := os.ReadFile(outputPath)
+	if err != nil {
+		t.Fatalf("Failed to read output file: %v", err)
+	}
+
+	contentStr := string(content)
+
+	// HTML should be preserved in some places
+	if !strings.Contains(contentStr, "<b>bold</b>") {
+		t.Error("Should preserve HTML formatting in descriptions")
+	}
+	if !strings.Contains(contentStr, "<h1>Heading with <em>emphasis</em>") {
+		t.Error("Should preserve HTML in headings")
+	}
+	if !strings.Contains(contentStr, "<strong>formatting</strong>") {
+		t.Error("Should preserve HTML in paragraphs")
+	}
+}
+
+// createTestCourseForHTML creates a test course for HTML export testing.
+func createTestCourseForHTML() *models.Course {
+	return &models.Course{
+		ShareID: "test-share-id",
+		Course: models.CourseInfo{
+			ID:             "test-course-id",
+			Title:          "Test Course",
+			Description:    "<p>Test course description with <strong>formatting</strong>.</p>",
+			NavigationMode: "free",
+			Lessons: []models.Lesson{
+				{
+					ID:    "section-1",
+					Title: "Test Section",
+					Type:  "section",
+				},
+				{
+					ID:          "lesson-1",
+					Title:       "Test Lesson",
+					Type:        "lesson",
+					Description: "<p>Test lesson description</p>",
+					Items: []models.Item{
+						{
+							Type: "text",
+							Items: []models.SubItem{
+								{
+									Heading:   "<h2>Test Heading</h2>",
+									Paragraph: "<p>Test paragraph content.</p>",
+								},
+							},
+						},
+						{
+							Type: "list",
+							Items: []models.SubItem{
+								{Paragraph: "<p>First list item</p>"},
+								{Paragraph: "<p>Second list item</p>"},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+// BenchmarkHTMLExporter_Export benchmarks the Export method.
+func BenchmarkHTMLExporter_Export(b *testing.B) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewHTMLExporter(htmlCleaner)
+	course := createTestCourseForHTML()
+
+	// Create temporary directory
+	tempDir := b.TempDir()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		outputPath := filepath.Join(tempDir, "benchmark-course.html")
+		_ = exporter.Export(course, outputPath)
+		// Clean up for next iteration
+		os.Remove(outputPath)
+	}
+}
+
+// BenchmarkHTMLExporter_ProcessTextItem benchmarks text item processing.
+func BenchmarkHTMLExporter_ProcessTextItem(b *testing.B) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &HTMLExporter{htmlCleaner: htmlCleaner}
+
+	item := models.Item{
+		Type: "text",
+		Items: []models.SubItem{
+			{
+				Heading:   "<h1>Benchmark Heading</h1>",
+				Paragraph: "<p>Benchmark paragraph with <strong>formatting</strong>.</p>",
+			},
+		},
+	}
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		var buf bytes.Buffer
+		exporter.processTextItem(&buf, item)
+	}
+}
+
+// BenchmarkHTMLExporter_ComplexCourse benchmarks export of a complex course.
+func BenchmarkHTMLExporter_ComplexCourse(b *testing.B) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewHTMLExporter(htmlCleaner)
+
+	// Create complex course for benchmarking
+	course := &models.Course{
+		ShareID: "benchmark-id",
+		Course: models.CourseInfo{
+			ID:          "benchmark-course",
+			Title:       "Benchmark Course",
+			Description: "<p>Complex course for performance testing</p>",
+			Lessons:     make([]models.Lesson, 10), // 10 lessons
+		},
+	}
+
+	// Fill with test data
+	for i := 0; i < 10; i++ {
+		lesson := models.Lesson{
+			ID:    "lesson-" + string(rune(i)),
+			Title: "Lesson " + string(rune(i)),
+			Type:  "lesson",
+			Items: make([]models.Item, 5), // 5 items per lesson
+		}
+
+		for j := 0; j < 5; j++ {
+			item := models.Item{
+				Type:  "text",
+				Items: make([]models.SubItem, 3), // 3 sub-items per item
+			}
+
+			for k := 0; k < 3; k++ {
+				item.Items[k] = models.SubItem{
+					Heading:   "<h3>Heading " + string(rune(k)) + "</h3>",
+					Paragraph: "<p>Paragraph content with <strong>formatting</strong> for performance testing.</p>",
+				}
+			}
+
+			lesson.Items[j] = item
+		}
+
+		course.Course.Lessons[i] = lesson
+	}
+
+	tempDir := b.TempDir()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		outputPath := filepath.Join(tempDir, "benchmark-complex.html")
+		_ = exporter.Export(course, outputPath)
+		os.Remove(outputPath)
+	}
+}
--- a/internal/exporters/markdown.go
+++ b/internal/exporters/markdown.go
@ -65,13 +65,15 @@ func (e *MarkdownExporter) Export(course *models.Course, outputPath string) erro
 	buf.WriteString("\n---\n\n")

 	// Process lessons
-	for i, lesson := range course.Course.Lessons {
+	lessonCounter := 0
+	for _, lesson := range course.Course.Lessons {
 		if lesson.Type == "section" {
 			buf.WriteString(fmt.Sprintf("# %s\n\n", lesson.Title))
 			continue
 		}

-		buf.WriteString(fmt.Sprintf("## Lesson %d: %s\n\n", i+1, lesson.Title))
+		lessonCounter++
+		buf.WriteString(fmt.Sprintf("## Lesson %d: %s\n\n", lessonCounter, lesson.Title))

 		if lesson.Description != "" {
 			buf.WriteString(fmt.Sprintf("%s\n\n", e.htmlCleaner.CleanHTML(lesson.Description)))
@ -110,6 +112,26 @@ func (e *MarkdownExporter) processItemToMarkdown(buf *bytes.Buffer, item models.

 	switch item.Type {
 	case "text":
+		e.processTextItem(buf, item, headingPrefix)
+	case "list":
+		e.processListItem(buf, item)
+	case "multimedia":
+		e.processMultimediaItem(buf, item, headingPrefix)
+	case "image":
+		e.processImageItem(buf, item, headingPrefix)
+	case "knowledgeCheck":
+		e.processKnowledgeCheckItem(buf, item, headingPrefix)
+	case "interactive":
+		e.processInteractiveItem(buf, item, headingPrefix)
+	case "divider":
+		e.processDividerItem(buf)
+	default:
+		e.processUnknownItem(buf, item, headingPrefix)
+	}
+}
+
+// processTextItem handles text content with headings and paragraphs
+func (e *MarkdownExporter) processTextItem(buf *bytes.Buffer, item models.Item, headingPrefix string) {
 	for _, subItem := range item.Items {
 		if subItem.Heading != "" {
 			heading := e.htmlCleaner.CleanHTML(subItem.Heading)
@ -124,8 +146,10 @@ func (e *MarkdownExporter) processItemToMarkdown(buf *bytes.Buffer, item models.
 			}
 		}
 	}
+}

-	case "list":
+// processListItem handles list items with bullet points
+func (e *MarkdownExporter) processListItem(buf *bytes.Buffer, item models.Item) {
 	for _, subItem := range item.Items {
 		if subItem.Paragraph != "" {
 			paragraph := e.htmlCleaner.CleanHTML(subItem.Paragraph)
@ -135,29 +159,48 @@ func (e *MarkdownExporter) processItemToMarkdown(buf *bytes.Buffer, item models.
 		}
 	}
 	buf.WriteString("\n")
+}

-	case "multimedia":
+// processMultimediaItem handles multimedia content including videos and images
+func (e *MarkdownExporter) processMultimediaItem(buf *bytes.Buffer, item models.Item, headingPrefix string) {
 	buf.WriteString(fmt.Sprintf("%s Media Content\n\n", headingPrefix))
 	for _, subItem := range item.Items {
+		e.processMediaSubItem(buf, subItem)
+	}
+	buf.WriteString("\n")
+}
+
+// processMediaSubItem processes individual media items (video/image)
+func (e *MarkdownExporter) processMediaSubItem(buf *bytes.Buffer, subItem models.SubItem) {
 	if subItem.Media != nil {
-				if subItem.Media.Video != nil {
-					buf.WriteString(fmt.Sprintf("**Video**: %s\n", subItem.Media.Video.OriginalUrl))
-					if subItem.Media.Video.Duration > 0 {
-						buf.WriteString(fmt.Sprintf("**Duration**: %d seconds\n", subItem.Media.Video.Duration))
-					}
-				}
-				if subItem.Media.Image != nil {
-					buf.WriteString(fmt.Sprintf("**Image**: %s\n", subItem.Media.Image.OriginalUrl))
-				}
+		e.processVideoMedia(buf, subItem.Media)
+		e.processImageMedia(buf, subItem.Media)
 	}
 	if subItem.Caption != "" {
 		caption := e.htmlCleaner.CleanHTML(subItem.Caption)
 		buf.WriteString(fmt.Sprintf("*%s*\n", caption))
 	}
-		}
-		buf.WriteString("\n")
+}

-	case "image":
+// processVideoMedia processes video media content
+func (e *MarkdownExporter) processVideoMedia(buf *bytes.Buffer, media *models.Media) {
+	if media.Video != nil {
+		buf.WriteString(fmt.Sprintf("**Video**: %s\n", media.Video.OriginalUrl))
+		if media.Video.Duration > 0 {
+			buf.WriteString(fmt.Sprintf("**Duration**: %d seconds\n", media.Video.Duration))
+		}
+	}
+}
+
+// processImageMedia processes image media content
+func (e *MarkdownExporter) processImageMedia(buf *bytes.Buffer, media *models.Media) {
+	if media.Image != nil {
+		buf.WriteString(fmt.Sprintf("**Image**: %s\n", media.Image.OriginalUrl))
+	}
+}
+
+// processImageItem handles standalone image items
+func (e *MarkdownExporter) processImageItem(buf *bytes.Buffer, item models.Item, headingPrefix string) {
 	buf.WriteString(fmt.Sprintf("%s Image\n\n", headingPrefix))
 	for _, subItem := range item.Items {
 		if subItem.Media != nil && subItem.Media.Image != nil {
@ -169,32 +212,46 @@ func (e *MarkdownExporter) processItemToMarkdown(buf *bytes.Buffer, item models.
 		}
 	}
 	buf.WriteString("\n")
+}

-	case "knowledgeCheck":
+// processKnowledgeCheckItem handles quiz questions and knowledge checks
+func (e *MarkdownExporter) processKnowledgeCheckItem(buf *bytes.Buffer, item models.Item, headingPrefix string) {
 	buf.WriteString(fmt.Sprintf("%s Knowledge Check\n\n", headingPrefix))
 	for _, subItem := range item.Items {
+		e.processQuestionSubItem(buf, subItem)
+	}
+	buf.WriteString("\n")
+}
+
+// processQuestionSubItem processes individual question items
+func (e *MarkdownExporter) processQuestionSubItem(buf *bytes.Buffer, subItem models.SubItem) {
 	if subItem.Title != "" {
 		title := e.htmlCleaner.CleanHTML(subItem.Title)
 		buf.WriteString(fmt.Sprintf("**Question**: %s\n\n", title))
 	}

+	e.processAnswers(buf, subItem.Answers)
+
+	if subItem.Feedback != "" {
+		feedback := e.htmlCleaner.CleanHTML(subItem.Feedback)
+		buf.WriteString(fmt.Sprintf("\n**Feedback**: %s\n", feedback))
+	}
+}
+
+// processAnswers processes answer choices for quiz questions
+func (e *MarkdownExporter) processAnswers(buf *bytes.Buffer, answers []models.Answer) {
 	buf.WriteString("**Answers**:\n")
-			for i, answer := range subItem.Answers {
+	for i, answer := range answers {
 		correctMark := ""
 		if answer.Correct {
 			correctMark = " ✓"
 		}
 		buf.WriteString(fmt.Sprintf("%d. %s%s\n", i+1, answer.Title, correctMark))
 	}
+}

-			if subItem.Feedback != "" {
-				feedback := e.htmlCleaner.CleanHTML(subItem.Feedback)
-				buf.WriteString(fmt.Sprintf("\n**Feedback**: %s\n", feedback))
-			}
-		}
-		buf.WriteString("\n")
-
-	case "interactive":
+// processInteractiveItem handles interactive content
+func (e *MarkdownExporter) processInteractiveItem(buf *bytes.Buffer, item models.Item, headingPrefix string) {
 	buf.WriteString(fmt.Sprintf("%s Interactive Content\n\n", headingPrefix))
 	for _, subItem := range item.Items {
 		if subItem.Title != "" {
@ -202,15 +259,25 @@ func (e *MarkdownExporter) processItemToMarkdown(buf *bytes.Buffer, item models.
 			buf.WriteString(fmt.Sprintf("**%s**\n\n", title))
 		}
 	}
+}

-	case "divider":
+// processDividerItem handles divider elements
+func (e *MarkdownExporter) processDividerItem(buf *bytes.Buffer) {
 	buf.WriteString("---\n\n")
+}

-	default:
-		// Handle unknown types
+// processUnknownItem handles unknown or unsupported item types
+func (e *MarkdownExporter) processUnknownItem(buf *bytes.Buffer, item models.Item, headingPrefix string) {
 	if len(item.Items) > 0 {
 		buf.WriteString(fmt.Sprintf("%s %s Content\n\n", headingPrefix, strings.Title(item.Type)))
 		for _, subItem := range item.Items {
+			e.processGenericSubItem(buf, subItem)
+		}
+	}
+}
+
+// processGenericSubItem processes sub-items for unknown types
+func (e *MarkdownExporter) processGenericSubItem(buf *bytes.Buffer, subItem models.SubItem) {
 	if subItem.Title != "" {
 		title := e.htmlCleaner.CleanHTML(subItem.Title)
 		buf.WriteString(fmt.Sprintf("**%s**\n\n", title))
@ -219,7 +286,4 @@ func (e *MarkdownExporter) processItemToMarkdown(buf *bytes.Buffer, item models.
 		paragraph := e.htmlCleaner.CleanHTML(subItem.Paragraph)
 		buf.WriteString(fmt.Sprintf("%s\n\n", paragraph))
 	}
-			}
-		}
-	}
 }
--- a/internal/exporters/markdown_test.go
+++ b/internal/exporters/markdown_test.go
@ -0,0 +1,693 @@
+// Package exporters_test provides tests for the markdown exporter.
+package exporters
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/kjanat/articulate-parser/internal/models"
+	"github.com/kjanat/articulate-parser/internal/services"
+)
+
+// TestNewMarkdownExporter tests the NewMarkdownExporter constructor.
+func TestNewMarkdownExporter(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewMarkdownExporter(htmlCleaner)
+
+	if exporter == nil {
+		t.Fatal("NewMarkdownExporter() returned nil")
+	}
+
+	// Type assertion to check internal structure
+	markdownExporter, ok := exporter.(*MarkdownExporter)
+	if !ok {
+		t.Fatal("NewMarkdownExporter() returned wrong type")
+	}
+
+	if markdownExporter.htmlCleaner == nil {
+		t.Error("htmlCleaner should not be nil")
+	}
+}
+
+// TestMarkdownExporter_GetSupportedFormat tests the GetSupportedFormat method.
+func TestMarkdownExporter_GetSupportedFormat(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewMarkdownExporter(htmlCleaner)
+
+	expected := "markdown"
+	result := exporter.GetSupportedFormat()
+
+	if result != expected {
+		t.Errorf("Expected format '%s', got '%s'", expected, result)
+	}
+}
+
+// TestMarkdownExporter_Export tests the Export method.
+func TestMarkdownExporter_Export(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewMarkdownExporter(htmlCleaner)
+
+	// Create test course
+	testCourse := createTestCourseForMarkdown()
+
+	// Create temporary directory and file
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "test-course.md")
+
+	// Test successful export
+	err := exporter.Export(testCourse, outputPath)
+	if err != nil {
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Check that file was created
+	if _, err := os.Stat(outputPath); os.IsNotExist(err) {
+		t.Fatal("Output file was not created")
+	}
+
+	// Read and verify content
+	content, err := os.ReadFile(outputPath)
+	if err != nil {
+		t.Fatalf("Failed to read output file: %v", err)
+	}
+
+	contentStr := string(content)
+
+	// Verify main course title
+	if !strings.Contains(contentStr, "# Test Course") {
+		t.Error("Output should contain course title as main heading")
+	}
+
+	// Verify course information section
+	if !strings.Contains(contentStr, "## Course Information") {
+		t.Error("Output should contain course information section")
+	}
+
+	// Verify course metadata
+	if !strings.Contains(contentStr, "- **Course ID**: test-course-id") {
+		t.Error("Output should contain course ID")
+	}
+
+	if !strings.Contains(contentStr, "- **Share ID**: test-share-id") {
+		t.Error("Output should contain share ID")
+	}
+
+	// Verify lesson content
+	if !strings.Contains(contentStr, "## Lesson 1: Test Lesson") {
+		t.Error("Output should contain lesson heading")
+	}
+
+	// Verify section handling
+	if !strings.Contains(contentStr, "# Test Section") {
+		t.Error("Output should contain section as main heading")
+	}
+}
+
+// TestMarkdownExporter_Export_InvalidPath tests export with invalid output path.
+func TestMarkdownExporter_Export_InvalidPath(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewMarkdownExporter(htmlCleaner)
+
+	testCourse := createTestCourseForMarkdown()
+
+	// Try to write to invalid path
+	invalidPath := "/invalid/path/that/does/not/exist/file.md"
+	err := exporter.Export(testCourse, invalidPath)
+
+	if err == nil {
+		t.Fatal("Expected error for invalid path, got nil")
+	}
+}
+
+// TestMarkdownExporter_ProcessTextItem tests the processTextItem method.
+func TestMarkdownExporter_ProcessTextItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "text",
+		Items: []models.SubItem{
+			{
+				Heading:   "<h1>Test Heading</h1>",
+				Paragraph: "<p>Test paragraph with <strong>bold</strong> text.</p>",
+			},
+			{
+				Paragraph: "<p>Another paragraph.</p>",
+			},
+		},
+	}
+
+	exporter.processTextItem(&buf, item, "###")
+
+	result := buf.String()
+	expected := "### Test Heading\n\nTest paragraph with bold text.\n\nAnother paragraph.\n\n"
+
+	if result != expected {
+		t.Errorf("Expected:\n%q\nGot:\n%q", expected, result)
+	}
+}
+
+// TestMarkdownExporter_ProcessListItem tests the processListItem method.
+func TestMarkdownExporter_ProcessListItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "list",
+		Items: []models.SubItem{
+			{Paragraph: "<p>First item</p>"},
+			{Paragraph: "<p>Second item with <em>emphasis</em></p>"},
+			{Paragraph: "<p>Third item</p>"},
+		},
+	}
+
+	exporter.processListItem(&buf, item)
+
+	result := buf.String()
+	expected := "- First item\n- Second item with emphasis\n- Third item\n\n"
+
+	if result != expected {
+		t.Errorf("Expected:\n%q\nGot:\n%q", expected, result)
+	}
+}
+
+// TestMarkdownExporter_ProcessMultimediaItem tests the processMultimediaItem method.
+func TestMarkdownExporter_ProcessMultimediaItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "multimedia",
+		Items: []models.SubItem{
+			{
+				Media: &models.Media{
+					Video: &models.VideoMedia{
+						OriginalUrl: "https://example.com/video.mp4",
+						Duration:    120,
+					},
+				},
+				Caption: "<p>Video caption</p>",
+			},
+		},
+	}
+
+	exporter.processMultimediaItem(&buf, item, "###")
+
+	result := buf.String()
+
+	if !strings.Contains(result, "### Media Content") {
+		t.Error("Should contain media content heading")
+	}
+	if !strings.Contains(result, "**Video**: https://example.com/video.mp4") {
+		t.Error("Should contain video URL")
+	}
+	if !strings.Contains(result, "**Duration**: 120 seconds") {
+		t.Error("Should contain video duration")
+	}
+	if !strings.Contains(result, "*Video caption*") {
+		t.Error("Should contain video caption")
+	}
+}
+
+// TestMarkdownExporter_ProcessImageItem tests the processImageItem method.
+func TestMarkdownExporter_ProcessImageItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "image",
+		Items: []models.SubItem{
+			{
+				Media: &models.Media{
+					Image: &models.ImageMedia{
+						OriginalUrl: "https://example.com/image.jpg",
+					},
+				},
+				Caption: "<p>Image caption</p>",
+			},
+		},
+	}
+
+	exporter.processImageItem(&buf, item, "###")
+
+	result := buf.String()
+
+	if !strings.Contains(result, "### Image") {
+		t.Error("Should contain image heading")
+	}
+	if !strings.Contains(result, "**Image**: https://example.com/image.jpg") {
+		t.Error("Should contain image URL")
+	}
+	if !strings.Contains(result, "*Image caption*") {
+		t.Error("Should contain image caption")
+	}
+}
+
+// TestMarkdownExporter_ProcessKnowledgeCheckItem tests the processKnowledgeCheckItem method.
+func TestMarkdownExporter_ProcessKnowledgeCheckItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "knowledgeCheck",
+		Items: []models.SubItem{
+			{
+				Title: "<p>What is the capital of France?</p>",
+				Answers: []models.Answer{
+					{Title: "London", Correct: false},
+					{Title: "Paris", Correct: true},
+					{Title: "Berlin", Correct: false},
+				},
+				Feedback: "<p>Paris is the capital of France.</p>",
+			},
+		},
+	}
+
+	exporter.processKnowledgeCheckItem(&buf, item, "###")
+
+	result := buf.String()
+
+	if !strings.Contains(result, "### Knowledge Check") {
+		t.Error("Should contain knowledge check heading")
+	}
+	if !strings.Contains(result, "**Question**: What is the capital of France?") {
+		t.Error("Should contain question")
+	}
+	if !strings.Contains(result, "**Answers**:") {
+		t.Error("Should contain answers heading")
+	}
+	if !strings.Contains(result, "2. Paris ✓") {
+		t.Error("Should mark correct answer")
+	}
+	if !strings.Contains(result, "**Feedback**: Paris is the capital of France.") {
+		t.Error("Should contain feedback")
+	}
+}
+
+// TestMarkdownExporter_ProcessInteractiveItem tests the processInteractiveItem method.
+func TestMarkdownExporter_ProcessInteractiveItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "interactive",
+		Items: []models.SubItem{
+			{Title: "<p>Interactive element title</p>"},
+		},
+	}
+
+	exporter.processInteractiveItem(&buf, item, "###")
+
+	result := buf.String()
+
+	if !strings.Contains(result, "### Interactive Content") {
+		t.Error("Should contain interactive content heading")
+	}
+	if !strings.Contains(result, "**Interactive element title**") {
+		t.Error("Should contain interactive element title")
+	}
+}
+
+// TestMarkdownExporter_ProcessDividerItem tests the processDividerItem method.
+func TestMarkdownExporter_ProcessDividerItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	exporter.processDividerItem(&buf)
+
+	result := buf.String()
+	expected := "---\n\n"
+
+	if result != expected {
+		t.Errorf("Expected %q, got %q", expected, result)
+	}
+}
+
+// TestMarkdownExporter_ProcessUnknownItem tests the processUnknownItem method.
+func TestMarkdownExporter_ProcessUnknownItem(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	item := models.Item{
+		Type: "unknown",
+		Items: []models.SubItem{
+			{
+				Title:     "<p>Unknown item title</p>",
+				Paragraph: "<p>Unknown item content</p>",
+			},
+		},
+	}
+
+	exporter.processUnknownItem(&buf, item, "###")
+
+	result := buf.String()
+
+	if !strings.Contains(result, "### Unknown Content") {
+		t.Error("Should contain unknown content heading")
+	}
+	if !strings.Contains(result, "**Unknown item title**") {
+		t.Error("Should contain unknown item title")
+	}
+	if !strings.Contains(result, "Unknown item content") {
+		t.Error("Should contain unknown item content")
+	}
+}
+
+// TestMarkdownExporter_ProcessVideoMedia tests the processVideoMedia method.
+func TestMarkdownExporter_ProcessVideoMedia(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	media := &models.Media{
+		Video: &models.VideoMedia{
+			OriginalUrl: "https://example.com/video.mp4",
+			Duration:    300,
+		},
+	}
+
+	exporter.processVideoMedia(&buf, media)
+
+	result := buf.String()
+
+	if !strings.Contains(result, "**Video**: https://example.com/video.mp4") {
+		t.Error("Should contain video URL")
+	}
+	if !strings.Contains(result, "**Duration**: 300 seconds") {
+		t.Error("Should contain video duration")
+	}
+}
+
+// TestMarkdownExporter_ProcessImageMedia tests the processImageMedia method.
+func TestMarkdownExporter_ProcessImageMedia(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	media := &models.Media{
+		Image: &models.ImageMedia{
+			OriginalUrl: "https://example.com/image.jpg",
+		},
+	}
+
+	exporter.processImageMedia(&buf, media)
+
+	result := buf.String()
+	expected := "**Image**: https://example.com/image.jpg\n"
+
+	if result != expected {
+		t.Errorf("Expected %q, got %q", expected, result)
+	}
+}
+
+// TestMarkdownExporter_ProcessAnswers tests the processAnswers method.
+func TestMarkdownExporter_ProcessAnswers(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	var buf bytes.Buffer
+	answers := []models.Answer{
+		{Title: "Answer 1", Correct: false},
+		{Title: "Answer 2", Correct: true},
+		{Title: "Answer 3", Correct: false},
+	}
+
+	exporter.processAnswers(&buf, answers)
+
+	result := buf.String()
+
+	if !strings.Contains(result, "**Answers**:") {
+		t.Error("Should contain answers heading")
+	}
+	if !strings.Contains(result, "1. Answer 1") {
+		t.Error("Should contain first answer")
+	}
+	if !strings.Contains(result, "2. Answer 2 ✓") {
+		t.Error("Should mark correct answer")
+	}
+	if !strings.Contains(result, "3. Answer 3") {
+		t.Error("Should contain third answer")
+	}
+}
+
+// TestMarkdownExporter_ProcessItemToMarkdown_AllTypes tests all item types.
+func TestMarkdownExporter_ProcessItemToMarkdown_AllTypes(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	tests := []struct {
+		name         string
+		itemType     string
+		expectedText string
+	}{
+		{
+			name:         "text item",
+			itemType:     "text",
+			expectedText: "", // processTextItem handles empty items
+		},
+		{
+			name:         "list item",
+			itemType:     "list",
+			expectedText: "\n", // Empty list adds newline
+		},
+		{
+			name:         "multimedia item",
+			itemType:     "multimedia",
+			expectedText: "### Media Content",
+		},
+		{
+			name:         "image item",
+			itemType:     "image",
+			expectedText: "### Image",
+		},
+		{
+			name:         "knowledgeCheck item",
+			itemType:     "knowledgeCheck",
+			expectedText: "### Knowledge Check",
+		},
+		{
+			name:         "interactive item",
+			itemType:     "interactive",
+			expectedText: "### Interactive Content",
+		},
+		{
+			name:         "divider item",
+			itemType:     "divider",
+			expectedText: "---",
+		},
+		{
+			name:         "unknown item",
+			itemType:     "unknown",
+			expectedText: "", // Empty unknown items don't add content
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			var buf bytes.Buffer
+			item := models.Item{Type: tt.itemType}
+
+			exporter.processItemToMarkdown(&buf, item, 3)
+
+			result := buf.String()
+			if tt.expectedText != "" && !strings.Contains(result, tt.expectedText) {
+				t.Errorf("Expected result to contain %q, got %q", tt.expectedText, result)
+			}
+		})
+	}
+}
+
+// TestMarkdownExporter_ComplexCourse tests export of a complex course structure.
+func TestMarkdownExporter_ComplexCourse(t *testing.T) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewMarkdownExporter(htmlCleaner)
+
+	// Create complex test course
+	course := &models.Course{
+		ShareID: "complex-test-id",
+		Author:  "Test Author",
+		Course: models.CourseInfo{
+			ID:             "complex-course",
+			Title:          "Complex Test Course",
+			Description:    "<p>This is a <strong>complex</strong> course description.</p>",
+			NavigationMode: "menu",
+			ExportSettings: &models.ExportSettings{
+				Format: "scorm",
+			},
+			Lessons: []models.Lesson{
+				{
+					ID:    "section-1",
+					Title: "Course Section",
+					Type:  "section",
+				},
+				{
+					ID:          "lesson-1",
+					Title:       "Introduction Lesson",
+					Type:        "lesson",
+					Description: "<p>Introduction to the course</p>",
+					Items: []models.Item{
+						{
+							Type: "text",
+							Items: []models.SubItem{
+								{
+									Heading:   "<h2>Welcome</h2>",
+									Paragraph: "<p>Welcome to our course!</p>",
+								},
+							},
+						},
+						{
+							Type: "list",
+							Items: []models.SubItem{
+								{Paragraph: "<p>First objective</p>"},
+								{Paragraph: "<p>Second objective</p>"},
+							},
+						},
+						{
+							Type: "knowledgeCheck",
+							Items: []models.SubItem{
+								{
+									Title: "<p>What will you learn?</p>",
+									Answers: []models.Answer{
+										{Title: "Nothing", Correct: false},
+										{Title: "Everything", Correct: true},
+									},
+									Feedback: "<p>Great choice!</p>",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	// Create temporary output file
+	tempDir := t.TempDir()
+	outputPath := filepath.Join(tempDir, "complex-course.md")
+
+	// Export course
+	err := exporter.Export(course, outputPath)
+	if err != nil {
+		t.Fatalf("Export failed: %v", err)
+	}
+
+	// Read and verify content
+	content, err := os.ReadFile(outputPath)
+	if err != nil {
+		t.Fatalf("Failed to read output file: %v", err)
+	}
+
+	contentStr := string(content)
+
+	// Verify various elements are present
+	checks := []string{
+		"# Complex Test Course",
+		"This is a complex course description.",
+		"- **Export Format**: scorm",
+		"# Course Section",
+		"## Lesson 1: Introduction Lesson",
+		"Introduction to the course",
+		"### Welcome",
+		"Welcome to our course!",
+		"- First objective",
+		"- Second objective",
+		"### Knowledge Check",
+		"**Question**: What will you learn?",
+		"2. Everything ✓",
+		"**Feedback**: Great choice!",
+	}
+
+	for _, check := range checks {
+		if !strings.Contains(contentStr, check) {
+			t.Errorf("Output should contain: %q", check)
+		}
+	}
+}
+
+// createTestCourseForMarkdown creates a test course for markdown export testing.
+func createTestCourseForMarkdown() *models.Course {
+	return &models.Course{
+		ShareID: "test-share-id",
+		Author:  "Test Author",
+		Course: models.CourseInfo{
+			ID:             "test-course-id",
+			Title:          "Test Course",
+			Description:    "Test course description",
+			NavigationMode: "menu",
+			Lessons: []models.Lesson{
+				{
+					ID:    "section-1",
+					Title: "Test Section",
+					Type:  "section",
+				},
+				{
+					ID:    "lesson-1",
+					Title: "Test Lesson",
+					Type:  "lesson",
+					Items: []models.Item{
+						{
+							Type: "text",
+							Items: []models.SubItem{
+								{
+									Heading:   "Test Heading",
+									Paragraph: "Test paragraph content",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+// BenchmarkMarkdownExporter_Export benchmarks the Export method.
+func BenchmarkMarkdownExporter_Export(b *testing.B) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := NewMarkdownExporter(htmlCleaner)
+	course := createTestCourseForMarkdown()
+
+	// Create temporary directory
+	tempDir := b.TempDir()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		outputPath := filepath.Join(tempDir, "benchmark-course.md")
+		_ = exporter.Export(course, outputPath)
+		// Clean up for next iteration
+		os.Remove(outputPath)
+	}
+}
+
+// BenchmarkMarkdownExporter_ProcessTextItem benchmarks the processTextItem method.
+func BenchmarkMarkdownExporter_ProcessTextItem(b *testing.B) {
+	htmlCleaner := services.NewHTMLCleaner()
+	exporter := &MarkdownExporter{htmlCleaner: htmlCleaner}
+
+	item := models.Item{
+		Type: "text",
+		Items: []models.SubItem{
+			{
+				Heading:   "<h1>Benchmark Heading</h1>",
+				Paragraph: "<p>Benchmark paragraph with <strong>bold</strong> text.</p>",
+			},
+		},
+	}
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		var buf bytes.Buffer
+		exporter.processTextItem(&buf, item, "###")
+	}
+}
--- a/internal/models/models_test.go
+++ b/internal/models/models_test.go
@ -0,0 +1,790 @@
+// Package models_test provides tests for the data models.
+package models
+
+import (
+	"encoding/json"
+	"reflect"
+	"testing"
+)
+
+// TestCourse_JSONMarshalUnmarshal tests JSON marshaling and unmarshaling of Course.
+func TestCourse_JSONMarshalUnmarshal(t *testing.T) {
+	original := Course{
+		ShareID: "test-share-id",
+		Author:  "Test Author",
+		Course: CourseInfo{
+			ID:             "course-123",
+			Title:          "Test Course",
+			Description:    "A test course description",
+			Color:          "#FF5733",
+			NavigationMode: "menu",
+			Lessons: []Lesson{
+				{
+					ID:          "lesson-1",
+					Title:       "First Lesson",
+					Description: "Lesson description",
+					Type:        "lesson",
+					Icon:        "icon-1",
+					Ready:       true,
+					CreatedAt:   "2023-01-01T00:00:00Z",
+					UpdatedAt:   "2023-01-02T00:00:00Z",
+				},
+			},
+			ExportSettings: &ExportSettings{
+				Title:  "Export Title",
+				Format: "scorm",
+			},
+		},
+		LabelSet: LabelSet{
+			ID:   "labelset-1",
+			Name: "Test Labels",
+		},
+	}
+
+	// Marshal to JSON
+	jsonData, err := json.Marshal(original)
+	if err != nil {
+		t.Fatalf("Failed to marshal Course to JSON: %v", err)
+	}
+
+	// Unmarshal from JSON
+	var unmarshaled Course
+	err = json.Unmarshal(jsonData, &unmarshaled)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal Course from JSON: %v", err)
+	}
+
+	// Compare structures
+	if !reflect.DeepEqual(original, unmarshaled) {
+		t.Errorf("Marshaled and unmarshaled Course structs do not match")
+		t.Logf("Original: %+v", original)
+		t.Logf("Unmarshaled: %+v", unmarshaled)
+	}
+}
+
+// TestCourseInfo_JSONMarshalUnmarshal tests JSON marshaling and unmarshaling of CourseInfo.
+func TestCourseInfo_JSONMarshalUnmarshal(t *testing.T) {
+	original := CourseInfo{
+		ID:             "course-456",
+		Title:          "Another Test Course",
+		Description:    "Another test description",
+		Color:          "#33FF57",
+		NavigationMode: "linear",
+		Lessons: []Lesson{
+			{
+				ID:    "lesson-2",
+				Title: "Second Lesson",
+				Type:  "section",
+				Items: []Item{
+					{
+						ID:      "item-1",
+						Type:    "text",
+						Family:  "text",
+						Variant: "paragraph",
+						Items: []SubItem{
+							{
+								Title:     "Sub Item Title",
+								Heading:   "Sub Item Heading",
+								Paragraph: "Sub item paragraph content",
+							},
+						},
+					},
+				},
+			},
+		},
+		CoverImage: &Media{
+			Image: &ImageMedia{
+				Key:         "img-123",
+				Type:        "jpg",
+				Width:       800,
+				Height:      600,
+				OriginalUrl: "https://example.com/image.jpg",
+			},
+		},
+	}
+
+	// Marshal to JSON
+	jsonData, err := json.Marshal(original)
+	if err != nil {
+		t.Fatalf("Failed to marshal CourseInfo to JSON: %v", err)
+	}
+
+	// Unmarshal from JSON
+	var unmarshaled CourseInfo
+	err = json.Unmarshal(jsonData, &unmarshaled)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal CourseInfo from JSON: %v", err)
+	}
+
+	// Compare structures
+	if !reflect.DeepEqual(original, unmarshaled) {
+		t.Errorf("Marshaled and unmarshaled CourseInfo structs do not match")
+	}
+}
+
+// TestLesson_JSONMarshalUnmarshal tests JSON marshaling and unmarshaling of Lesson.
+func TestLesson_JSONMarshalUnmarshal(t *testing.T) {
+	original := Lesson{
+		ID:          "lesson-test",
+		Title:       "Test Lesson",
+		Description: "Test lesson description",
+		Type:        "lesson",
+		Icon:        "lesson-icon",
+		Ready:       true,
+		CreatedAt:   "2023-06-01T12:00:00Z",
+		UpdatedAt:   "2023-06-01T13:00:00Z",
+		Position:    map[string]interface{}{"x": 1, "y": 2},
+		Items: []Item{
+			{
+				ID:      "item-test",
+				Type:    "multimedia",
+				Family:  "media",
+				Variant: "video",
+				Items: []SubItem{
+					{
+						Caption: "Video caption",
+						Media: &Media{
+							Video: &VideoMedia{
+								Key:         "video-123",
+								URL:         "https://example.com/video.mp4",
+								Type:        "mp4",
+								Duration:    120,
+								OriginalUrl: "https://example.com/video.mp4",
+							},
+						},
+					},
+				},
+				Settings: map[string]interface{}{"autoplay": false},
+				Data:     map[string]interface{}{"metadata": "test"},
+			},
+		},
+	}
+
+	// Marshal to JSON
+	jsonData, err := json.Marshal(original)
+	if err != nil {
+		t.Fatalf("Failed to marshal Lesson to JSON: %v", err)
+	}
+
+	// Unmarshal from JSON
+	var unmarshaled Lesson
+	err = json.Unmarshal(jsonData, &unmarshaled)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal Lesson from JSON: %v", err)
+	}
+
+	// Compare structures
+	if !compareLessons(original, unmarshaled) {
+		t.Errorf("Marshaled and unmarshaled Lesson structs do not match")
+	}
+}
+
+// TestItem_JSONMarshalUnmarshal tests JSON marshaling and unmarshaling of Item.
+func TestItem_JSONMarshalUnmarshal(t *testing.T) {
+	original := Item{
+		ID:      "item-json-test",
+		Type:    "knowledgeCheck",
+		Family:  "assessment",
+		Variant: "multipleChoice",
+		Items: []SubItem{
+			{
+				Title: "What is the answer?",
+				Answers: []Answer{
+					{Title: "Option A", Correct: false},
+					{Title: "Option B", Correct: true},
+					{Title: "Option C", Correct: false},
+				},
+				Feedback: "Well done!",
+			},
+		},
+		Settings: map[string]interface{}{
+			"allowRetry": true,
+			"showAnswer": true,
+		},
+		Data: map[string]interface{}{
+			"points": 10,
+			"weight": 1.5,
+		},
+	}
+
+	// Marshal to JSON
+	jsonData, err := json.Marshal(original)
+	if err != nil {
+		t.Fatalf("Failed to marshal Item to JSON: %v", err)
+	}
+
+	// Unmarshal from JSON
+	var unmarshaled Item
+	err = json.Unmarshal(jsonData, &unmarshaled)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal Item from JSON: %v", err)
+	}
+
+	// Compare structures
+	if !compareItem(original, unmarshaled) {
+		t.Errorf("Marshaled and unmarshaled Item structs do not match")
+	}
+}
+
+// TestSubItem_JSONMarshalUnmarshal tests JSON marshaling and unmarshaling of SubItem.
+func TestSubItem_JSONMarshalUnmarshal(t *testing.T) {
+	original := SubItem{
+		Title:     "Test SubItem Title",
+		Heading:   "Test SubItem Heading",
+		Paragraph: "Test paragraph with content",
+		Caption:   "Test caption",
+		Feedback:  "Test feedback message",
+		Answers: []Answer{
+			{Title: "First answer", Correct: true},
+			{Title: "Second answer", Correct: false},
+		},
+		Media: &Media{
+			Image: &ImageMedia{
+				Key:           "subitem-img",
+				Type:          "png",
+				Width:         400,
+				Height:        300,
+				OriginalUrl:   "https://example.com/subitem.png",
+				CrushedKey:    "crushed-123",
+				UseCrushedKey: true,
+			},
+		},
+	}
+
+	// Marshal to JSON
+	jsonData, err := json.Marshal(original)
+	if err != nil {
+		t.Fatalf("Failed to marshal SubItem to JSON: %v", err)
+	}
+
+	// Unmarshal from JSON
+	var unmarshaled SubItem
+	err = json.Unmarshal(jsonData, &unmarshaled)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal SubItem from JSON: %v", err)
+	}
+
+	// Compare structures
+	if !reflect.DeepEqual(original, unmarshaled) {
+		t.Errorf("Marshaled and unmarshaled SubItem structs do not match")
+	}
+}
+
+// TestAnswer_JSONMarshalUnmarshal tests JSON marshaling and unmarshaling of Answer.
+func TestAnswer_JSONMarshalUnmarshal(t *testing.T) {
+	original := Answer{
+		Title:   "Test answer text",
+		Correct: true,
+	}
+
+	// Marshal to JSON
+	jsonData, err := json.Marshal(original)
+	if err != nil {
+		t.Fatalf("Failed to marshal Answer to JSON: %v", err)
+	}
+
+	// Unmarshal from JSON
+	var unmarshaled Answer
+	err = json.Unmarshal(jsonData, &unmarshaled)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal Answer from JSON: %v", err)
+	}
+
+	// Compare structures
+	if !reflect.DeepEqual(original, unmarshaled) {
+		t.Errorf("Marshaled and unmarshaled Answer structs do not match")
+	}
+}
+
+// TestMedia_JSONMarshalUnmarshal tests JSON marshaling and unmarshaling of Media.
+func TestMedia_JSONMarshalUnmarshal(t *testing.T) {
+	// Test with Image
+	originalImage := Media{
+		Image: &ImageMedia{
+			Key:           "media-img-test",
+			Type:          "jpeg",
+			Width:         1200,
+			Height:        800,
+			OriginalUrl:   "https://example.com/media.jpg",
+			CrushedKey:    "crushed-media",
+			UseCrushedKey: false,
+		},
+	}
+
+	jsonData, err := json.Marshal(originalImage)
+	if err != nil {
+		t.Fatalf("Failed to marshal Media with Image to JSON: %v", err)
+	}
+
+	var unmarshaledImage Media
+	err = json.Unmarshal(jsonData, &unmarshaledImage)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal Media with Image from JSON: %v", err)
+	}
+
+	if !reflect.DeepEqual(originalImage, unmarshaledImage) {
+		t.Errorf("Marshaled and unmarshaled Media with Image do not match")
+	}
+
+	// Test with Video
+	originalVideo := Media{
+		Video: &VideoMedia{
+			Key:         "media-video-test",
+			URL:         "https://example.com/media.mp4",
+			Type:        "mp4",
+			Duration:    300,
+			Poster:      "https://example.com/poster.jpg",
+			Thumbnail:   "https://example.com/thumb.jpg",
+			InputKey:    "input-123",
+			OriginalUrl: "https://example.com/original.mp4",
+		},
+	}
+
+	jsonData, err = json.Marshal(originalVideo)
+	if err != nil {
+		t.Fatalf("Failed to marshal Media with Video to JSON: %v", err)
+	}
+
+	var unmarshaledVideo Media
+	err = json.Unmarshal(jsonData, &unmarshaledVideo)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal Media with Video from JSON: %v", err)
+	}
+
+	if !reflect.DeepEqual(originalVideo, unmarshaledVideo) {
+		t.Errorf("Marshaled and unmarshaled Media with Video do not match")
+	}
+}
+
+// TestImageMedia_JSONMarshalUnmarshal tests JSON marshaling and unmarshaling of ImageMedia.
+func TestImageMedia_JSONMarshalUnmarshal(t *testing.T) {
+	original := ImageMedia{
+		Key:           "image-media-test",
+		Type:          "gif",
+		Width:         640,
+		Height:        480,
+		OriginalUrl:   "https://example.com/image.gif",
+		CrushedKey:    "crushed-gif",
+		UseCrushedKey: true,
+	}
+
+	// Marshal to JSON
+	jsonData, err := json.Marshal(original)
+	if err != nil {
+		t.Fatalf("Failed to marshal ImageMedia to JSON: %v", err)
+	}
+
+	// Unmarshal from JSON
+	var unmarshaled ImageMedia
+	err = json.Unmarshal(jsonData, &unmarshaled)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal ImageMedia from JSON: %v", err)
+	}
+
+	// Compare structures
+	if !reflect.DeepEqual(original, unmarshaled) {
+		t.Errorf("Marshaled and unmarshaled ImageMedia structs do not match")
+	}
+}
+
+// TestVideoMedia_JSONMarshalUnmarshal tests JSON marshaling and unmarshaling of VideoMedia.
+func TestVideoMedia_JSONMarshalUnmarshal(t *testing.T) {
+	original := VideoMedia{
+		Key:         "video-media-test",
+		URL:         "https://example.com/video.webm",
+		Type:        "webm",
+		Duration:    450,
+		Poster:      "https://example.com/poster.jpg",
+		Thumbnail:   "https://example.com/thumbnail.jpg",
+		InputKey:    "upload-456",
+		OriginalUrl: "https://example.com/original.webm",
+	}
+
+	// Marshal to JSON
+	jsonData, err := json.Marshal(original)
+	if err != nil {
+		t.Fatalf("Failed to marshal VideoMedia to JSON: %v", err)
+	}
+
+	// Unmarshal from JSON
+	var unmarshaled VideoMedia
+	err = json.Unmarshal(jsonData, &unmarshaled)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal VideoMedia from JSON: %v", err)
+	}
+
+	// Compare structures
+	if !reflect.DeepEqual(original, unmarshaled) {
+		t.Errorf("Marshaled and unmarshaled VideoMedia structs do not match")
+	}
+}
+
+// TestExportSettings_JSONMarshalUnmarshal tests JSON marshaling and unmarshaling of ExportSettings.
+func TestExportSettings_JSONMarshalUnmarshal(t *testing.T) {
+	original := ExportSettings{
+		Title:  "Custom Export Title",
+		Format: "xAPI",
+	}
+
+	// Marshal to JSON
+	jsonData, err := json.Marshal(original)
+	if err != nil {
+		t.Fatalf("Failed to marshal ExportSettings to JSON: %v", err)
+	}
+
+	// Unmarshal from JSON
+	var unmarshaled ExportSettings
+	err = json.Unmarshal(jsonData, &unmarshaled)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal ExportSettings from JSON: %v", err)
+	}
+
+	// Compare structures
+	if !reflect.DeepEqual(original, unmarshaled) {
+		t.Errorf("Marshaled and unmarshaled ExportSettings structs do not match")
+	}
+}
+
+// TestLabelSet_JSONMarshalUnmarshal tests JSON marshaling and unmarshaling of LabelSet.
+func TestLabelSet_JSONMarshalUnmarshal(t *testing.T) {
+	original := LabelSet{
+		ID:   "labelset-test",
+		Name: "Test Label Set",
+	}
+
+	// Marshal to JSON
+	jsonData, err := json.Marshal(original)
+	if err != nil {
+		t.Fatalf("Failed to marshal LabelSet to JSON: %v", err)
+	}
+
+	// Unmarshal from JSON
+	var unmarshaled LabelSet
+	err = json.Unmarshal(jsonData, &unmarshaled)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal LabelSet from JSON: %v", err)
+	}
+
+	// Compare structures
+	if !reflect.DeepEqual(original, unmarshaled) {
+		t.Errorf("Marshaled and unmarshaled LabelSet structs do not match")
+	}
+}
+
+// TestEmptyStructures tests marshaling and unmarshaling of empty structures.
+func TestEmptyStructures(t *testing.T) {
+	testCases := []struct {
+		name string
+		data interface{}
+	}{
+		{"Empty Course", Course{}},
+		{"Empty CourseInfo", CourseInfo{}},
+		{"Empty Lesson", Lesson{}},
+		{"Empty Item", Item{}},
+		{"Empty SubItem", SubItem{}},
+		{"Empty Answer", Answer{}},
+		{"Empty Media", Media{}},
+		{"Empty ImageMedia", ImageMedia{}},
+		{"Empty VideoMedia", VideoMedia{}},
+		{"Empty ExportSettings", ExportSettings{}},
+		{"Empty LabelSet", LabelSet{}},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			// Marshal to JSON
+			jsonData, err := json.Marshal(tc.data)
+			if err != nil {
+				t.Fatalf("Failed to marshal %s to JSON: %v", tc.name, err)
+			}
+
+			// Unmarshal from JSON
+			result := reflect.New(reflect.TypeOf(tc.data)).Interface()
+			err = json.Unmarshal(jsonData, result)
+			if err != nil {
+				t.Fatalf("Failed to unmarshal %s from JSON: %v", tc.name, err)
+			}
+
+			// Basic validation that no errors occurred
+			if len(jsonData) == 0 {
+				t.Errorf("%s should produce some JSON output", tc.name)
+			}
+		})
+	}
+}
+
+// TestNilPointerSafety tests that nil pointers in optional fields are handled correctly.
+func TestNilPointerSafety(t *testing.T) {
+	course := Course{
+		ShareID: "nil-test",
+		Course: CourseInfo{
+			ID:             "nil-course",
+			Title:          "Nil Pointer Test",
+			CoverImage:     nil, // Test nil pointer
+			ExportSettings: nil, // Test nil pointer
+			Lessons: []Lesson{
+				{
+					ID:    "lesson-nil",
+					Title: "Lesson with nil media",
+					Items: []Item{
+						{
+							ID:   "item-nil",
+							Type: "text",
+							Items: []SubItem{
+								{
+									Title: "SubItem with nil media",
+									Media: nil, // Test nil pointer
+								},
+							},
+							Media: nil, // Test nil pointer
+						},
+					},
+				},
+			},
+		},
+	}
+
+	// Marshal to JSON
+	jsonData, err := json.Marshal(course)
+	if err != nil {
+		t.Fatalf("Failed to marshal Course with nil pointers to JSON: %v", err)
+	}
+
+	// Unmarshal from JSON
+	var unmarshaled Course
+	err = json.Unmarshal(jsonData, &unmarshaled)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal Course with nil pointers from JSON: %v", err)
+	}
+
+	// Basic validation
+	if unmarshaled.ShareID != "nil-test" {
+		t.Error("ShareID should be preserved")
+	}
+	if unmarshaled.Course.Title != "Nil Pointer Test" {
+		t.Error("Course title should be preserved")
+	}
+}
+
+// TestJSONTagsPresence tests that JSON tags are properly defined.
+func TestJSONTagsPresence(t *testing.T) {
+	// Test that important fields have JSON tags
+	courseType := reflect.TypeOf(Course{})
+	if courseType.Kind() == reflect.Struct {
+		field, found := courseType.FieldByName("ShareID")
+		if !found {
+			t.Error("ShareID field not found")
+		} else {
+			tag := field.Tag.Get("json")
+			if tag == "" {
+				t.Error("ShareID should have json tag")
+			}
+			if tag != "shareId" {
+				t.Errorf("ShareID json tag should be 'shareId', got '%s'", tag)
+			}
+		}
+	}
+
+	// Test CourseInfo
+	courseInfoType := reflect.TypeOf(CourseInfo{})
+	if courseInfoType.Kind() == reflect.Struct {
+		field, found := courseInfoType.FieldByName("NavigationMode")
+		if !found {
+			t.Error("NavigationMode field not found")
+		} else {
+			tag := field.Tag.Get("json")
+			if tag == "" {
+				t.Error("NavigationMode should have json tag")
+			}
+		}
+	}
+}
+
+// BenchmarkCourse_JSONMarshal benchmarks JSON marshaling of Course.
+func BenchmarkCourse_JSONMarshal(b *testing.B) {
+	course := Course{
+		ShareID: "benchmark-id",
+		Author:  "Benchmark Author",
+		Course: CourseInfo{
+			ID:    "benchmark-course",
+			Title: "Benchmark Course",
+			Lessons: []Lesson{
+				{
+					ID:    "lesson-1",
+					Title: "Lesson 1",
+					Items: []Item{
+						{
+							ID:   "item-1",
+							Type: "text",
+							Items: []SubItem{
+								{Title: "SubItem 1"},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, _ = json.Marshal(course)
+	}
+}
+
+// BenchmarkCourse_JSONUnmarshal benchmarks JSON unmarshaling of Course.
+func BenchmarkCourse_JSONUnmarshal(b *testing.B) {
+	course := Course{
+		ShareID: "benchmark-id",
+		Author:  "Benchmark Author",
+		Course: CourseInfo{
+			ID:    "benchmark-course",
+			Title: "Benchmark Course",
+			Lessons: []Lesson{
+				{
+					ID:    "lesson-1",
+					Title: "Lesson 1",
+					Items: []Item{
+						{
+							ID:   "item-1",
+							Type: "text",
+							Items: []SubItem{
+								{Title: "SubItem 1"},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	jsonData, _ := json.Marshal(course)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		var result Course
+		_ = json.Unmarshal(jsonData, &result)
+	}
+}
+
+// compareMaps compares two interface{} values that should be maps
+func compareMaps(original, unmarshaled interface{}) bool {
+	origMap, origOk := original.(map[string]interface{})
+	unMap, unOk := unmarshaled.(map[string]interface{})
+
+	if !origOk || !unOk {
+		// If not maps, use deep equal
+		return reflect.DeepEqual(original, unmarshaled)
+	}
+
+	if len(origMap) != len(unMap) {
+		return false
+	}
+
+	for key, origVal := range origMap {
+		unVal, exists := unMap[key]
+		if !exists {
+			return false
+		}
+
+		// Handle numeric type conversion from JSON
+		switch origVal := origVal.(type) {
+		case int:
+			if unFloat, ok := unVal.(float64); ok {
+				if float64(origVal) != unFloat {
+					return false
+				}
+			} else {
+				return false
+			}
+		case float64:
+			if unFloat, ok := unVal.(float64); ok {
+				if origVal != unFloat {
+					return false
+				}
+			} else {
+				return false
+			}
+		default:
+			if !reflect.DeepEqual(origVal, unVal) {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// compareLessons compares two Lesson structs accounting for JSON type conversion
+func compareLessons(original, unmarshaled Lesson) bool {
+	// Compare all fields except Position and Items
+	if original.ID != unmarshaled.ID ||
+		original.Title != unmarshaled.Title ||
+		original.Description != unmarshaled.Description ||
+		original.Type != unmarshaled.Type ||
+		original.Icon != unmarshaled.Icon ||
+		original.Ready != unmarshaled.Ready ||
+		original.CreatedAt != unmarshaled.CreatedAt ||
+		original.UpdatedAt != unmarshaled.UpdatedAt {
+		return false
+	}
+
+	// Compare Position
+	if !compareMaps(original.Position, unmarshaled.Position) {
+		return false
+	}
+
+	// Compare Items
+	return compareItems(original.Items, unmarshaled.Items)
+}
+
+// compareItems compares two Item slices accounting for JSON type conversion
+func compareItems(original, unmarshaled []Item) bool {
+	if len(original) != len(unmarshaled) {
+		return false
+	}
+
+	for i := range original {
+		if !compareItem(original[i], unmarshaled[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// compareItem compares two Item structs accounting for JSON type conversion
+func compareItem(original, unmarshaled Item) bool {
+	// Compare basic fields
+	if original.ID != unmarshaled.ID ||
+		original.Type != unmarshaled.Type ||
+		original.Family != unmarshaled.Family ||
+		original.Variant != unmarshaled.Variant {
+		return false
+	}
+
+	// Compare Settings and Data
+	if !compareMaps(original.Settings, unmarshaled.Settings) {
+		return false
+	}
+
+	if !compareMaps(original.Data, unmarshaled.Data) {
+		return false
+	}
+
+	// Compare Items (SubItems)
+	if len(original.Items) != len(unmarshaled.Items) {
+		return false
+	}
+
+	for i := range original.Items {
+		if !reflect.DeepEqual(original.Items[i], unmarshaled.Items[i]) {
+			return false
+		}
+	}
+
+	// Compare Media
+	if !reflect.DeepEqual(original.Media, unmarshaled.Media) {
+		return false
+	}
+
+	return true
+}
--- a/internal/services/app_test.go
+++ b/internal/services/app_test.go
@ -0,0 +1,353 @@
+// Package services_test provides tests for the services package.
+package services
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/kjanat/articulate-parser/internal/interfaces"
+	"github.com/kjanat/articulate-parser/internal/models"
+)
+
+// MockCourseParser is a mock implementation of interfaces.CourseParser for testing.
+type MockCourseParser struct {
+	mockFetchCourse        func(uri string) (*models.Course, error)
+	mockLoadCourseFromFile func(filePath string) (*models.Course, error)
+}
+
+func (m *MockCourseParser) FetchCourse(uri string) (*models.Course, error) {
+	if m.mockFetchCourse != nil {
+		return m.mockFetchCourse(uri)
+	}
+	return nil, errors.New("not implemented")
+}
+
+func (m *MockCourseParser) LoadCourseFromFile(filePath string) (*models.Course, error) {
+	if m.mockLoadCourseFromFile != nil {
+		return m.mockLoadCourseFromFile(filePath)
+	}
+	return nil, errors.New("not implemented")
+}
+
+// MockExporter is a mock implementation of interfaces.Exporter for testing.
+type MockExporter struct {
+	mockExport             func(course *models.Course, outputPath string) error
+	mockGetSupportedFormat func() string
+}
+
+func (m *MockExporter) Export(course *models.Course, outputPath string) error {
+	if m.mockExport != nil {
+		return m.mockExport(course, outputPath)
+	}
+	return nil
+}
+
+func (m *MockExporter) GetSupportedFormat() string {
+	if m.mockGetSupportedFormat != nil {
+		return m.mockGetSupportedFormat()
+	}
+	return "mock"
+}
+
+// MockExporterFactory is a mock implementation of interfaces.ExporterFactory for testing.
+type MockExporterFactory struct {
+	mockCreateExporter      func(format string) (*MockExporter, error)
+	mockGetSupportedFormats func() []string
+}
+
+func (m *MockExporterFactory) CreateExporter(format string) (interfaces.Exporter, error) {
+	if m.mockCreateExporter != nil {
+		exporter, err := m.mockCreateExporter(format)
+		return exporter, err
+	}
+	return &MockExporter{}, nil
+}
+
+func (m *MockExporterFactory) GetSupportedFormats() []string {
+	if m.mockGetSupportedFormats != nil {
+		return m.mockGetSupportedFormats()
+	}
+	return []string{"mock"}
+}
+
+// createTestCourse creates a sample course for testing purposes.
+func createTestCourse() *models.Course {
+	return &models.Course{
+		ShareID: "test-share-id",
+		Author:  "Test Author",
+		Course: models.CourseInfo{
+			ID:          "test-course-id",
+			Title:       "Test Course",
+			Description: "This is a test course",
+			Lessons: []models.Lesson{
+				{
+					ID:    "lesson-1",
+					Title: "Test Lesson",
+					Type:  "lesson",
+					Items: []models.Item{
+						{
+							ID:   "item-1",
+							Type: "text",
+							Items: []models.SubItem{
+								{
+									ID:        "subitem-1",
+									Title:     "Test Title",
+									Paragraph: "Test paragraph content",
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+// TestNewApp tests the NewApp constructor.
+func TestNewApp(t *testing.T) {
+	parser := &MockCourseParser{}
+	factory := &MockExporterFactory{}
+
+	app := NewApp(parser, factory)
+
+	if app == nil {
+		t.Fatal("NewApp() returned nil")
+	}
+
+	if app.parser != parser {
+		t.Error("App parser was not set correctly")
+	}
+
+	// Test that the factory is set (we can't directly compare interface values)
+	formats := app.GetSupportedFormats()
+	if len(formats) == 0 {
+		t.Error("App exporterFactory was not set correctly - no supported formats")
+	}
+}
+
+// TestApp_ProcessCourseFromFile tests the ProcessCourseFromFile method.
+func TestApp_ProcessCourseFromFile(t *testing.T) {
+	testCourse := createTestCourse()
+
+	tests := []struct {
+		name          string
+		filePath      string
+		format        string
+		outputPath    string
+		setupMocks    func(*MockCourseParser, *MockExporterFactory, *MockExporter)
+		expectedError string
+	}{
+		{
+			name:       "successful processing",
+			filePath:   "test.json",
+			format:     "markdown",
+			outputPath: "output.md",
+			setupMocks: func(parser *MockCourseParser, factory *MockExporterFactory, exporter *MockExporter) {
+				parser.mockLoadCourseFromFile = func(filePath string) (*models.Course, error) {
+					if filePath != "test.json" {
+						t.Errorf("Expected filePath 'test.json', got '%s'", filePath)
+					}
+					return testCourse, nil
+				}
+
+				factory.mockCreateExporter = func(format string) (*MockExporter, error) {
+					if format != "markdown" {
+						t.Errorf("Expected format 'markdown', got '%s'", format)
+					}
+					return exporter, nil
+				}
+
+				exporter.mockExport = func(course *models.Course, outputPath string) error {
+					if outputPath != "output.md" {
+						t.Errorf("Expected outputPath 'output.md', got '%s'", outputPath)
+					}
+					if course != testCourse {
+						t.Error("Expected course to match testCourse")
+					}
+					return nil
+				}
+			},
+		},
+		{
+			name:       "file loading error",
+			filePath:   "nonexistent.json",
+			format:     "markdown",
+			outputPath: "output.md",
+			setupMocks: func(parser *MockCourseParser, factory *MockExporterFactory, exporter *MockExporter) {
+				parser.mockLoadCourseFromFile = func(filePath string) (*models.Course, error) {
+					return nil, errors.New("file not found")
+				}
+			},
+			expectedError: "failed to load course from file",
+		},
+		{
+			name:       "exporter creation error",
+			filePath:   "test.json",
+			format:     "unsupported",
+			outputPath: "output.txt",
+			setupMocks: func(parser *MockCourseParser, factory *MockExporterFactory, exporter *MockExporter) {
+				parser.mockLoadCourseFromFile = func(filePath string) (*models.Course, error) {
+					return testCourse, nil
+				}
+
+				factory.mockCreateExporter = func(format string) (*MockExporter, error) {
+					return nil, errors.New("unsupported format")
+				}
+			},
+			expectedError: "failed to create exporter",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			parser := &MockCourseParser{}
+			exporter := &MockExporter{}
+			factory := &MockExporterFactory{}
+
+			tt.setupMocks(parser, factory, exporter)
+
+			app := NewApp(parser, factory)
+			err := app.ProcessCourseFromFile(tt.filePath, tt.format, tt.outputPath)
+
+			if tt.expectedError != "" {
+				if err == nil {
+					t.Fatalf("Expected error containing '%s', got nil", tt.expectedError)
+				}
+				if !contains(err.Error(), tt.expectedError) {
+					t.Errorf("Expected error containing '%s', got '%s'", tt.expectedError, err.Error())
+				}
+			} else {
+				if err != nil {
+					t.Errorf("Expected no error, got: %v", err)
+				}
+			}
+		})
+	}
+}
+
+// TestApp_ProcessCourseFromURI tests the ProcessCourseFromURI method.
+func TestApp_ProcessCourseFromURI(t *testing.T) {
+	testCourse := createTestCourse()
+
+	tests := []struct {
+		name          string
+		uri           string
+		format        string
+		outputPath    string
+		setupMocks    func(*MockCourseParser, *MockExporterFactory, *MockExporter)
+		expectedError string
+	}{
+		{
+			name:       "successful processing",
+			uri:        "https://rise.articulate.com/share/test123",
+			format:     "docx",
+			outputPath: "output.docx",
+			setupMocks: func(parser *MockCourseParser, factory *MockExporterFactory, exporter *MockExporter) {
+				parser.mockFetchCourse = func(uri string) (*models.Course, error) {
+					if uri != "https://rise.articulate.com/share/test123" {
+						t.Errorf("Expected uri 'https://rise.articulate.com/share/test123', got '%s'", uri)
+					}
+					return testCourse, nil
+				}
+
+				factory.mockCreateExporter = func(format string) (*MockExporter, error) {
+					if format != "docx" {
+						t.Errorf("Expected format 'docx', got '%s'", format)
+					}
+					return exporter, nil
+				}
+
+				exporter.mockExport = func(course *models.Course, outputPath string) error {
+					if outputPath != "output.docx" {
+						t.Errorf("Expected outputPath 'output.docx', got '%s'", outputPath)
+					}
+					return nil
+				}
+			},
+		},
+		{
+			name:       "fetch error",
+			uri:        "invalid-uri",
+			format:     "docx",
+			outputPath: "output.docx",
+			setupMocks: func(parser *MockCourseParser, factory *MockExporterFactory, exporter *MockExporter) {
+				parser.mockFetchCourse = func(uri string) (*models.Course, error) {
+					return nil, errors.New("network error")
+				}
+			},
+			expectedError: "failed to fetch course",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			parser := &MockCourseParser{}
+			exporter := &MockExporter{}
+			factory := &MockExporterFactory{}
+
+			tt.setupMocks(parser, factory, exporter)
+
+			app := NewApp(parser, factory)
+			err := app.ProcessCourseFromURI(tt.uri, tt.format, tt.outputPath)
+
+			if tt.expectedError != "" {
+				if err == nil {
+					t.Fatalf("Expected error containing '%s', got nil", tt.expectedError)
+				}
+				if !contains(err.Error(), tt.expectedError) {
+					t.Errorf("Expected error containing '%s', got '%s'", tt.expectedError, err.Error())
+				}
+			} else {
+				if err != nil {
+					t.Errorf("Expected no error, got: %v", err)
+				}
+			}
+		})
+	}
+}
+
+// TestApp_GetSupportedFormats tests the GetSupportedFormats method.
+func TestApp_GetSupportedFormats(t *testing.T) {
+	expectedFormats := []string{"markdown", "docx", "pdf"}
+
+	parser := &MockCourseParser{}
+	factory := &MockExporterFactory{
+		mockGetSupportedFormats: func() []string {
+			return expectedFormats
+		},
+	}
+
+	app := NewApp(parser, factory)
+	formats := app.GetSupportedFormats()
+
+	if len(formats) != len(expectedFormats) {
+		t.Errorf("Expected %d formats, got %d", len(expectedFormats), len(formats))
+	}
+
+	for i, format := range formats {
+		if format != expectedFormats[i] {
+			t.Errorf("Expected format '%s' at index %d, got '%s'", expectedFormats[i], i, format)
+		}
+	}
+}
+
+// contains checks if a string contains a substring.
+func contains(s, substr string) bool {
+	return len(s) >= len(substr) &&
+		(len(substr) == 0 ||
+			s == substr ||
+			(len(s) > len(substr) &&
+				(s[:len(substr)] == substr ||
+					s[len(s)-len(substr):] == substr ||
+					containsSubstring(s, substr))))
+}
+
+// containsSubstring checks if s contains substr as a substring.
+func containsSubstring(s, substr string) bool {
+	for i := 0; i <= len(s)-len(substr); i++ {
+		if s[i:i+len(substr)] == substr {
+			return true
+		}
+	}
+	return false
+}
--- a/internal/services/html_cleaner_test.go
+++ b/internal/services/html_cleaner_test.go
@ -0,0 +1,325 @@
+// Package services_test provides tests for the HTML cleaner service.
+package services
+
+import (
+	"strings"
+	"testing"
+)
+
+// TestNewHTMLCleaner tests the NewHTMLCleaner constructor.
+func TestNewHTMLCleaner(t *testing.T) {
+	cleaner := NewHTMLCleaner()
+
+	if cleaner == nil {
+		t.Fatal("NewHTMLCleaner() returned nil")
+	}
+}
+
+// TestHTMLCleaner_CleanHTML tests the CleanHTML method with various HTML inputs.
+func TestHTMLCleaner_CleanHTML(t *testing.T) {
+	cleaner := NewHTMLCleaner()
+
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "plain text (no HTML)",
+			input:    "This is plain text",
+			expected: "This is plain text",
+		},
+		{
+			name:     "empty string",
+			input:    "",
+			expected: "",
+		},
+		{
+			name:     "simple HTML tag",
+			input:    "<p>Hello world</p>",
+			expected: "Hello world",
+		},
+		{
+			name:     "multiple HTML tags",
+			input:    "<h1>Title</h1><p>Paragraph text</p>",
+			expected: "TitleParagraph text",
+		},
+		{
+			name:     "nested HTML tags",
+			input:    "<div><h1>Title</h1><p>Paragraph with <strong>bold</strong> text</p></div>",
+			expected: "TitleParagraph with bold text",
+		},
+		{
+			name:     "HTML with attributes",
+			input:    "<p class=\"test\" id=\"para1\">Text with attributes</p>",
+			expected: "Text with attributes",
+		},
+		{
+			name:     "self-closing tags",
+			input:    "Line 1<br/>Line 2<hr/>End",
+			expected: "Line 1Line 2End",
+		},
+		{
+			name:     "HTML entities - basic",
+			input:    "AT&amp;T &lt;company&gt; &quot;quoted&quot; &nbsp; text",
+			expected: "AT&T <company> \"quoted\" text",
+		},
+		{
+			name:     "HTML entities - apostrophe",
+			input:    "It&#39;s a test",
+			expected: "It's a test",
+		},
+		{
+			name:     "HTML entities - special characters",
+			input:    "&iuml;ber &euml;lite &eacute;cart&eacute;",
+			expected: "ïber ëlite écarté",
+		},
+		{
+			name:     "HTML entities - nbsp",
+			input:    "Word1&nbsp;&nbsp;&nbsp;Word2",
+			expected: "Word1 Word2",
+		},
+		{
+			name:     "mixed HTML and entities",
+			input:    "<p>Hello &amp; welcome to <strong>our</strong> site!</p>",
+			expected: "Hello & welcome to our site!",
+		},
+		{
+			name:     "multiple whitespace",
+			input:    "Text   with\t\tmultiple\n\nspaces",
+			expected: "Text with multiple spaces",
+		},
+		{
+			name:     "whitespace with HTML",
+			input:    "<p>  Text  with  </p>  <div>  spaces  </div>  ",
+			expected: "Text with spaces",
+		},
+		{
+			name:     "complex content",
+			input:    "<div class=\"content\"><h1>Course Title</h1><p>This is a <em>great</em> course about &amp; HTML entities like &nbsp; and &quot;quotes&quot;.</p></div>",
+			expected: "Course TitleThis is a great course about & HTML entities like and \"quotes\".",
+		},
+		{
+			name:     "malformed HTML",
+			input:    "<p>Unclosed paragraph<div>Another <span>tag</p></div>",
+			expected: "Unclosed paragraphAnother tag",
+		},
+		{
+			name:     "HTML comments (should be removed)",
+			input:    "Text before<!-- This is a comment -->Text after",
+			expected: "Text beforeText after",
+		},
+		{
+			name:     "script and style tags content",
+			input:    "<script>alert('test');</script>Content<style>body{color:red;}</style>",
+			expected: "alert('test');Contentbody{color:red;}",
+		},
+		{
+			name:     "line breaks and formatting",
+			input:    "<p>Line 1</p>\n<p>Line 2</p>\n<p>Line 3</p>",
+			expected: "Line 1 Line 2 Line 3",
+		},
+		{
+			name:     "only whitespace",
+			input:    "   \t\n   ",
+			expected: "",
+		},
+		{
+			name:     "only HTML tags",
+			input:    "<div><p></p></div>",
+			expected: "",
+		},
+		{
+			name:     "HTML with newlines",
+			input:    "<p>\n  Paragraph with\n  line breaks\n</p>",
+			expected: "Paragraph with line breaks",
+		},
+		{
+			name:     "complex nested structure",
+			input:    "<article><header><h1>Title</h1></header><section><p>First paragraph with <a href=\"#\">link</a>.</p><ul><li>Item 1</li><li>Item 2</li></ul></section></article>",
+			expected: "TitleFirst paragraph with link.Item 1Item 2",
+		},
+		{
+			name:     "entities in attributes (should still be processed)",
+			input:    "<p title=\"AT&amp;T\">Content</p>",
+			expected: "Content",
+		},
+		{
+			name:     "special HTML5 entities",
+			input:    "Left arrow &larr; Right arrow &rarr;",
+			expected: "Left arrow &larr; Right arrow &rarr;", // These are not handled by the cleaner
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := cleaner.CleanHTML(tt.input)
+			if result != tt.expected {
+				t.Errorf("CleanHTML(%q) = %q, want %q", tt.input, result, tt.expected)
+			}
+		})
+	}
+}
+
+// TestHTMLCleaner_CleanHTML_LargeContent tests the CleanHTML method with large content.
+func TestHTMLCleaner_CleanHTML_LargeContent(t *testing.T) {
+	cleaner := NewHTMLCleaner()
+
+	// Create a large HTML string
+	var builder strings.Builder
+	builder.WriteString("<html><body>")
+	for i := 0; i < 1000; i++ {
+		builder.WriteString("<p>Paragraph ")
+		builder.WriteString(string(rune('0' + i%10)))
+		builder.WriteString(" with some content &amp; entities.</p>")
+	}
+	builder.WriteString("</body></html>")
+
+	input := builder.String()
+	result := cleaner.CleanHTML(input)
+
+	// Check that HTML tags are removed
+	if strings.Contains(result, "<") || strings.Contains(result, ">") {
+		t.Error("Result should not contain HTML tags")
+	}
+
+	// Check that content is preserved
+	if !strings.Contains(result, "Paragraph") {
+		t.Error("Result should contain paragraph content")
+	}
+
+	// Check that entities are converted
+	if strings.Contains(result, "&amp;") {
+		t.Error("Result should not contain unconverted HTML entities")
+	}
+	if !strings.Contains(result, "&") {
+		t.Error("Result should contain converted ampersand")
+	}
+}
+
+// TestHTMLCleaner_CleanHTML_EdgeCases tests edge cases for the CleanHTML method.
+func TestHTMLCleaner_CleanHTML_EdgeCases(t *testing.T) {
+	cleaner := NewHTMLCleaner()
+
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "only entities",
+			input:    "&amp;&lt;&gt;&quot;&#39;&nbsp;",
+			expected: "&<>\"'",
+		},
+		{
+			name:     "repeated entities",
+			input:    "&amp;&amp;&amp;",
+			expected: "&&&",
+		},
+		{
+			name:     "entities without semicolon (should not be converted)",
+			input:    "&amp test &lt test",
+			expected: "&amp test &lt test",
+		},
+		{
+			name:     "mixed valid and invalid entities",
+			input:    "&amp; &invalid; &lt; &fake;",
+			expected: "& &invalid; < &fake;",
+		},
+		{
+			name:     "unclosed tag at end",
+			input:    "Content <p>with unclosed",
+			expected: "Content with unclosed",
+		},
+		{
+			name:     "tag with no closing bracket",
+			input:    "Content <p class='test' with no closing bracket",
+			expected: "Content <p class='test' with no closing bracket",
+		},
+		{
+			name:     "extremely nested tags",
+			input:    "<div><div><div><div><div>Deep content</div></div></div></div></div>",
+			expected: "Deep content",
+		},
+		{
+			name:     "empty tags with whitespace",
+			input:    "<p>   </p><div>\t\n</div>",
+			expected: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := cleaner.CleanHTML(tt.input)
+			if result != tt.expected {
+				t.Errorf("CleanHTML(%q) = %q, want %q", tt.input, result, tt.expected)
+			}
+		})
+	}
+}
+
+// TestHTMLCleaner_CleanHTML_Unicode tests Unicode content handling.
+func TestHTMLCleaner_CleanHTML_Unicode(t *testing.T) {
+	cleaner := NewHTMLCleaner()
+
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "unicode characters",
+			input:    "<p>Hello 世界! Café naïve résumé</p>",
+			expected: "Hello 世界! Café naïve résumé",
+		},
+		{
+			name:     "unicode with entities",
+			input:    "<p>Unicode: 你好 &amp; emoji: 🌍</p>",
+			expected: "Unicode: 你好 & emoji: 🌍",
+		},
+		{
+			name:     "mixed scripts",
+			input:    "<div>English العربية русский 日本語</div>",
+			expected: "English العربية русский 日本語",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := cleaner.CleanHTML(tt.input)
+			if result != tt.expected {
+				t.Errorf("CleanHTML(%q) = %q, want %q", tt.input, result, tt.expected)
+			}
+		})
+	}
+}
+
+// BenchmarkHTMLCleaner_CleanHTML benchmarks the CleanHTML method.
+func BenchmarkHTMLCleaner_CleanHTML(b *testing.B) {
+	cleaner := NewHTMLCleaner()
+	input := "<div class=\"content\"><h1>Course Title</h1><p>This is a <em>great</em> course about &amp; HTML entities like &nbsp; and &quot;quotes&quot;.</p><ul><li>Item 1</li><li>Item 2</li></ul></div>"
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		cleaner.CleanHTML(input)
+	}
+}
+
+// BenchmarkHTMLCleaner_CleanHTML_Large benchmarks the CleanHTML method with large content.
+func BenchmarkHTMLCleaner_CleanHTML_Large(b *testing.B) {
+	cleaner := NewHTMLCleaner()
+
+	// Create a large HTML string
+	var builder strings.Builder
+	for i := 0; i < 100; i++ {
+		builder.WriteString("<p>Paragraph ")
+		builder.WriteString(string(rune('0' + i%10)))
+		builder.WriteString(" with some content &amp; entities &lt;test&gt;.</p>")
+	}
+	input := builder.String()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		cleaner.CleanHTML(input)
+	}
+}
--- a/internal/services/parser.go
+++ b/internal/services/parser.go
@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/url"
 	"os"
 	"regexp"
 	"time"
@ -112,6 +113,17 @@ func (p *ArticulateParser) LoadCourseFromFile(filePath string) (*models.Course,
 //   - The share ID string if found
 //   - An error if the share ID can't be extracted from the URI
 func (p *ArticulateParser) extractShareID(uri string) (string, error) {
+	// Parse the URL to validate the domain
+	parsedURL, err := url.Parse(uri)
+	if err != nil {
+		return "", fmt.Errorf("invalid URI: %s", uri)
+	}
+
+	// Validate that it's an Articulate Rise domain
+	if parsedURL.Host != "rise.articulate.com" {
+		return "", fmt.Errorf("invalid domain for Articulate Rise URI: %s", parsedURL.Host)
+	}
+
 	re := regexp.MustCompile(`/share/([a-zA-Z0-9_-]+)`)
 	matches := re.FindStringSubmatch(uri)
 	if len(matches) < 2 {
--- a/internal/services/parser_test.go
+++ b/internal/services/parser_test.go
@ -0,0 +1,440 @@
+// Package services_test provides tests for the parser service.
+package services
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/kjanat/articulate-parser/internal/models"
+)
+
+// TestNewArticulateParser tests the NewArticulateParser constructor.
+func TestNewArticulateParser(t *testing.T) {
+	parser := NewArticulateParser()
+
+	if parser == nil {
+		t.Fatal("NewArticulateParser() returned nil")
+	}
+
+	// Type assertion to check internal structure
+	articulateParser, ok := parser.(*ArticulateParser)
+	if !ok {
+		t.Fatal("NewArticulateParser() returned wrong type")
+	}
+
+	expectedBaseURL := "https://rise.articulate.com"
+	if articulateParser.BaseURL != expectedBaseURL {
+		t.Errorf("Expected BaseURL '%s', got '%s'", expectedBaseURL, articulateParser.BaseURL)
+	}
+
+	if articulateParser.Client == nil {
+		t.Error("Client should not be nil")
+	}
+
+	expectedTimeout := 30 * time.Second
+	if articulateParser.Client.Timeout != expectedTimeout {
+		t.Errorf("Expected timeout %v, got %v", expectedTimeout, articulateParser.Client.Timeout)
+	}
+}
+
+// TestArticulateParser_FetchCourse tests the FetchCourse method.
+func TestArticulateParser_FetchCourse(t *testing.T) {
+	// Create a test course object
+	testCourse := &models.Course{
+		ShareID: "test-share-id",
+		Author:  "Test Author",
+		Course: models.CourseInfo{
+			ID:          "test-course-id",
+			Title:       "Test Course",
+			Description: "Test Description",
+		},
+	}
+
+	// Create test server
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// Check request path
+		expectedPath := "/api/rise-runtime/boot/share/test-share-id"
+		if r.URL.Path != expectedPath {
+			t.Errorf("Expected path '%s', got '%s'", expectedPath, r.URL.Path)
+		}
+
+		// Check request method
+		if r.Method != http.MethodGet {
+			t.Errorf("Expected method GET, got %s", r.Method)
+		}
+
+		// Return mock response
+		w.Header().Set("Content-Type", "application/json")
+		if err := json.NewEncoder(w).Encode(testCourse); err != nil {
+			t.Fatalf("Failed to encode test course: %v", err)
+		}
+	}))
+	defer server.Close()
+
+	// Create parser with test server URL
+	parser := &ArticulateParser{
+		BaseURL: server.URL,
+		Client: &http.Client{
+			Timeout: 5 * time.Second,
+		},
+	}
+
+	tests := []struct {
+		name          string
+		uri           string
+		expectedError string
+	}{
+		{
+			name: "valid articulate rise URI",
+			uri:  "https://rise.articulate.com/share/test-share-id#/",
+		},
+		{
+			name: "valid articulate rise URI without fragment",
+			uri:  "https://rise.articulate.com/share/test-share-id",
+		},
+		{
+			name:          "invalid URI format",
+			uri:           "invalid-uri",
+			expectedError: "invalid domain for Articulate Rise URI:",
+		},
+		{
+			name:          "empty URI",
+			uri:           "",
+			expectedError: "invalid domain for Articulate Rise URI:",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			course, err := parser.FetchCourse(tt.uri)
+
+			if tt.expectedError != "" {
+				if err == nil {
+					t.Fatalf("Expected error containing '%s', got nil", tt.expectedError)
+				}
+				if !strings.Contains(err.Error(), tt.expectedError) {
+					t.Errorf("Expected error containing '%s', got '%s'", tt.expectedError, err.Error())
+				}
+			} else {
+				if err != nil {
+					t.Fatalf("Expected no error, got: %v", err)
+				}
+				if course == nil {
+					t.Fatal("Expected course, got nil")
+				}
+				if course.ShareID != testCourse.ShareID {
+					t.Errorf("Expected ShareID '%s', got '%s'", testCourse.ShareID, course.ShareID)
+				}
+			}
+		})
+	}
+}
+
+// TestArticulateParser_FetchCourse_NetworkError tests network error handling.
+func TestArticulateParser_FetchCourse_NetworkError(t *testing.T) {
+	// Create parser with invalid URL to simulate network error
+	parser := &ArticulateParser{
+		BaseURL: "http://localhost:99999", // Invalid port
+		Client: &http.Client{
+			Timeout: 1 * time.Millisecond, // Very short timeout
+		},
+	}
+
+	_, err := parser.FetchCourse("https://rise.articulate.com/share/test-share-id")
+	if err == nil {
+		t.Fatal("Expected network error, got nil")
+	}
+
+	if !strings.Contains(err.Error(), "failed to fetch course data") {
+		t.Errorf("Expected error to contain 'failed to fetch course data', got '%s'", err.Error())
+	}
+}
+
+// TestArticulateParser_FetchCourse_InvalidJSON tests invalid JSON response handling.
+func TestArticulateParser_FetchCourse_InvalidJSON(t *testing.T) {
+	// Create test server that returns invalid JSON
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte("invalid json"))
+	}))
+	defer server.Close()
+
+	parser := &ArticulateParser{
+		BaseURL: server.URL,
+		Client: &http.Client{
+			Timeout: 5 * time.Second,
+		},
+	}
+
+	_, err := parser.FetchCourse("https://rise.articulate.com/share/test-share-id")
+	if err == nil {
+		t.Fatal("Expected JSON parsing error, got nil")
+	}
+
+	if !strings.Contains(err.Error(), "failed to unmarshal JSON") {
+		t.Errorf("Expected error to contain 'failed to unmarshal JSON', got '%s'", err.Error())
+	}
+}
+
+// TestArticulateParser_LoadCourseFromFile tests the LoadCourseFromFile method.
+func TestArticulateParser_LoadCourseFromFile(t *testing.T) {
+	// Create a temporary test file
+	testCourse := &models.Course{
+		ShareID: "file-test-share-id",
+		Author:  "File Test Author",
+		Course: models.CourseInfo{
+			ID:          "file-test-course-id",
+			Title:       "File Test Course",
+			Description: "File Test Description",
+		},
+	}
+
+	// Create temporary directory and file
+	tempDir := t.TempDir()
+	tempFile := filepath.Join(tempDir, "test-course.json")
+
+	// Write test data to file
+	data, err := json.Marshal(testCourse)
+	if err != nil {
+		t.Fatalf("Failed to marshal test course: %v", err)
+	}
+
+	if err := os.WriteFile(tempFile, data, 0644); err != nil {
+		t.Fatalf("Failed to write test file: %v", err)
+	}
+
+	parser := NewArticulateParser()
+
+	tests := []struct {
+		name          string
+		filePath      string
+		expectedError string
+	}{
+		{
+			name:     "valid file",
+			filePath: tempFile,
+		},
+		{
+			name:          "nonexistent file",
+			filePath:      filepath.Join(tempDir, "nonexistent.json"),
+			expectedError: "failed to read file",
+		},
+		{
+			name:          "empty path",
+			filePath:      "",
+			expectedError: "failed to read file",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			course, err := parser.LoadCourseFromFile(tt.filePath)
+
+			if tt.expectedError != "" {
+				if err == nil {
+					t.Fatalf("Expected error containing '%s', got nil", tt.expectedError)
+				}
+				if !strings.Contains(err.Error(), tt.expectedError) {
+					t.Errorf("Expected error containing '%s', got '%s'", tt.expectedError, err.Error())
+				}
+			} else {
+				if err != nil {
+					t.Fatalf("Expected no error, got: %v", err)
+				}
+				if course == nil {
+					t.Fatal("Expected course, got nil")
+				}
+				if course.ShareID != testCourse.ShareID {
+					t.Errorf("Expected ShareID '%s', got '%s'", testCourse.ShareID, course.ShareID)
+				}
+			}
+		})
+	}
+}
+
+// TestArticulateParser_LoadCourseFromFile_InvalidJSON tests invalid JSON file handling.
+func TestArticulateParser_LoadCourseFromFile_InvalidJSON(t *testing.T) {
+	// Create temporary file with invalid JSON
+	tempDir := t.TempDir()
+	tempFile := filepath.Join(tempDir, "invalid.json")
+
+	if err := os.WriteFile(tempFile, []byte("invalid json content"), 0644); err != nil {
+		t.Fatalf("Failed to write test file: %v", err)
+	}
+
+	parser := NewArticulateParser()
+	_, err := parser.LoadCourseFromFile(tempFile)
+
+	if err == nil {
+		t.Fatal("Expected JSON parsing error, got nil")
+	}
+
+	if !strings.Contains(err.Error(), "failed to unmarshal JSON") {
+		t.Errorf("Expected error to contain 'failed to unmarshal JSON', got '%s'", err.Error())
+	}
+}
+
+// TestExtractShareID tests the extractShareID method.
+func TestExtractShareID(t *testing.T) {
+	parser := &ArticulateParser{}
+
+	tests := []struct {
+		name     string
+		uri      string
+		expected string
+		hasError bool
+	}{
+		{
+			name:     "standard articulate rise URI with fragment",
+			uri:      "https://rise.articulate.com/share/N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO#/",
+			expected: "N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO",
+		},
+		{
+			name:     "standard articulate rise URI without fragment",
+			uri:      "https://rise.articulate.com/share/N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO",
+			expected: "N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO",
+		},
+		{
+			name:     "URI with trailing slash",
+			uri:      "https://rise.articulate.com/share/N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO/",
+			expected: "N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO",
+		},
+		{
+			name:     "short share ID",
+			uri:      "https://rise.articulate.com/share/abc123",
+			expected: "abc123",
+		},
+		{
+			name:     "share ID with hyphens and underscores",
+			uri:      "https://rise.articulate.com/share/test_ID-123_abc",
+			expected: "test_ID-123_abc",
+		},
+		{
+			name:     "invalid URI - no share path",
+			uri:      "https://rise.articulate.com/",
+			hasError: true,
+		},
+		{
+			name:     "invalid URI - wrong domain",
+			uri:      "https://example.com/share/test123",
+			hasError: true,
+		},
+		{
+			name:     "invalid URI - no share ID",
+			uri:      "https://rise.articulate.com/share/",
+			hasError: true,
+		},
+		{
+			name:     "empty URI",
+			uri:      "",
+			hasError: true,
+		},
+		{
+			name:     "malformed URI",
+			uri:      "not-a-uri",
+			hasError: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := parser.extractShareID(tt.uri)
+
+			if tt.hasError {
+				if err == nil {
+					t.Fatalf("Expected error for URI '%s', got nil", tt.uri)
+				}
+			} else {
+				if err != nil {
+					t.Fatalf("Expected no error for URI '%s', got: %v", tt.uri, err)
+				}
+				if result != tt.expected {
+					t.Errorf("Expected share ID '%s', got '%s'", tt.expected, result)
+				}
+			}
+		})
+	}
+}
+
+// TestBuildAPIURL tests the buildAPIURL method.
+func TestBuildAPIURL(t *testing.T) {
+	parser := &ArticulateParser{
+		BaseURL: "https://rise.articulate.com",
+	}
+
+	tests := []struct {
+		name     string
+		shareID  string
+		expected string
+	}{
+		{
+			name:     "standard share ID",
+			shareID:  "N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO",
+			expected: "https://rise.articulate.com/api/rise-runtime/boot/share/N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO",
+		},
+		{
+			name:     "short share ID",
+			shareID:  "abc123",
+			expected: "https://rise.articulate.com/api/rise-runtime/boot/share/abc123",
+		},
+		{
+			name:     "share ID with special characters",
+			shareID:  "test_ID-123_abc",
+			expected: "https://rise.articulate.com/api/rise-runtime/boot/share/test_ID-123_abc",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := parser.buildAPIURL(tt.shareID)
+			if result != tt.expected {
+				t.Errorf("Expected URL '%s', got '%s'", tt.expected, result)
+			}
+		})
+	}
+}
+
+// TestBuildAPIURL_DifferentBaseURL tests buildAPIURL with different base URLs.
+func TestBuildAPIURL_DifferentBaseURL(t *testing.T) {
+	parser := &ArticulateParser{
+		BaseURL: "https://custom.domain.com",
+	}
+
+	shareID := "test123"
+	expected := "https://custom.domain.com/api/rise-runtime/boot/share/test123"
+	result := parser.buildAPIURL(shareID)
+
+	if result != expected {
+		t.Errorf("Expected URL '%s', got '%s'", expected, result)
+	}
+}
+
+// BenchmarkExtractShareID benchmarks the extractShareID method.
+func BenchmarkExtractShareID(b *testing.B) {
+	parser := &ArticulateParser{}
+	uri := "https://rise.articulate.com/share/N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO#/"
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, _ = parser.extractShareID(uri)
+	}
+}
+
+// BenchmarkBuildAPIURL benchmarks the buildAPIURL method.
+func BenchmarkBuildAPIURL(b *testing.B) {
+	parser := &ArticulateParser{
+		BaseURL: "https://rise.articulate.com",
+	}
+	shareID := "N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO"
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = parser.buildAPIURL(shareID)
+	}
+}
--- a/internal/version/version.go
+++ b/internal/version/version.go
@ -5,7 +5,7 @@ package version
 // Version information.
 var (
 	// Version is the current version of the application.
-	Version = "0.1.1"
+	Version = "0.3.1"

 	// BuildTime is the time the binary was built.
 	BuildTime = "unknown"
--- a/main.go
+++ b/main.go
@ -16,6 +16,12 @@ import (
 // It handles command-line arguments, sets up dependencies,
 // and coordinates the parsing and exporting of courses.
 func main() {
+	os.Exit(run(os.Args))
+}
+
+// run contains the main application logic and returns an exit code.
+// This function is testable as it doesn't call os.Exit directly.
+func run(args []string) int {
 	// Dependency injection setup
 	htmlCleaner := services.NewHTMLCleaner()
 	parser := services.NewArticulateParser()
@ -23,20 +29,20 @@ func main() {
 	app := services.NewApp(parser, exporterFactory)

 	// Check for required command-line arguments
-	if len(os.Args) < 4 {
-		fmt.Printf("Usage: %s <source> <format> <output>\n", os.Args[0])
+	if len(args) < 4 {
+		fmt.Printf("Usage: %s <source> <format> <output>\n", args[0])
 		fmt.Printf("  source: URI or file path to the course\n")
 		fmt.Printf("  format: export format (%s)\n", joinStrings(app.GetSupportedFormats(), ", "))
 		fmt.Printf("  output: output file path\n")
 		fmt.Println("\nExample:")
-		fmt.Printf("  %s articulate-sample.json markdown output.md\n", os.Args[0])
-		fmt.Printf("  %s https://rise.articulate.com/share/xyz docx output.docx\n", os.Args[0])
-		os.Exit(1)
+		fmt.Printf("  %s articulate-sample.json markdown output.md\n", args[0])
+		fmt.Printf("  %s https://rise.articulate.com/share/xyz docx output.docx\n", args[0])
+		return 1
 	}

-	source := os.Args[1]
-	format := os.Args[2]
-	output := os.Args[3]
+	source := args[1]
+	format := args[2]
+	output := args[3]

 	var err error

@ -48,10 +54,12 @@ func main() {
 	}

 	if err != nil {
-		log.Fatalf("Error processing course: %v", err)
+		log.Printf("Error processing course: %v", err)
+		return 1
 	}

 	fmt.Printf("Successfully exported course to %s\n", output)
+	return 0
 }

 // isURI checks if a string is a URI by looking for http:// or https:// prefixes.
--- a/main_test.go
+++ b/main_test.go
@ -0,0 +1,478 @@
+// Package main_test provides tests for the main package utility functions.
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"strings"
+	"testing"
+)
+
+// TestIsURI tests the isURI function with various input scenarios.
+func TestIsURI(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected bool
+	}{
+		{
+			name:     "valid HTTP URI",
+			input:    "http://example.com",
+			expected: true,
+		},
+		{
+			name:     "valid HTTPS URI",
+			input:    "https://example.com",
+			expected: true,
+		},
+		{
+			name:     "valid Articulate Rise URI",
+			input:    "https://rise.articulate.com/share/N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO#/",
+			expected: true,
+		},
+		{
+			name:     "local file path",
+			input:    "C:\\Users\\test\\file.json",
+			expected: false,
+		},
+		{
+			name:     "relative file path",
+			input:    "./sample.json",
+			expected: false,
+		},
+		{
+			name:     "filename only",
+			input:    "sample.json",
+			expected: false,
+		},
+		{
+			name:     "empty string",
+			input:    "",
+			expected: false,
+		},
+		{
+			name:     "short string",
+			input:    "http",
+			expected: false,
+		},
+		{
+			name:     "malformed URI",
+			input:    "htp://example.com",
+			expected: false,
+		},
+		{
+			name:     "FTP URI",
+			input:    "ftp://example.com",
+			expected: false,
+		},
+		{
+			name:     "HTTP with extra characters",
+			input:    "xhttp://example.com",
+			expected: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := isURI(tt.input)
+			if result != tt.expected {
+				t.Errorf("isURI(%q) = %v, want %v", tt.input, result, tt.expected)
+			}
+		})
+	}
+}
+
+// TestJoinStrings tests the joinStrings function with various input scenarios.
+func TestJoinStrings(t *testing.T) {
+	tests := []struct {
+		name      string
+		strs      []string
+		separator string
+		expected  string
+	}{
+		{
+			name:      "empty slice",
+			strs:      []string{},
+			separator: ", ",
+			expected:  "",
+		},
+		{
+			name:      "single string",
+			strs:      []string{"hello"},
+			separator: ", ",
+			expected:  "hello",
+		},
+		{
+			name:      "two strings with comma separator",
+			strs:      []string{"markdown", "docx"},
+			separator: ", ",
+			expected:  "markdown, docx",
+		},
+		{
+			name:      "three strings with comma separator",
+			strs:      []string{"markdown", "md", "docx"},
+			separator: ", ",
+			expected:  "markdown, md, docx",
+		},
+		{
+			name:      "multiple strings with pipe separator",
+			strs:      []string{"option1", "option2", "option3"},
+			separator: " | ",
+			expected:  "option1 | option2 | option3",
+		},
+		{
+			name:      "strings with no separator",
+			strs:      []string{"a", "b", "c"},
+			separator: "",
+			expected:  "abc",
+		},
+		{
+			name:      "strings with newline separator",
+			strs:      []string{"line1", "line2", "line3"},
+			separator: "\n",
+			expected:  "line1\nline2\nline3",
+		},
+		{
+			name:      "empty strings in slice",
+			strs:      []string{"", "middle", ""},
+			separator: "-",
+			expected:  "-middle-",
+		},
+		{
+			name:      "nil slice",
+			strs:      nil,
+			separator: ", ",
+			expected:  "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := joinStrings(tt.strs, tt.separator)
+			if result != tt.expected {
+				t.Errorf("joinStrings(%v, %q) = %q, want %q", tt.strs, tt.separator, result, tt.expected)
+			}
+		})
+	}
+}
+
+// BenchmarkIsURI benchmarks the isURI function performance.
+func BenchmarkIsURI(b *testing.B) {
+	testStr := "https://rise.articulate.com/share/N_APNg40Vr2CSH2xNz-ZLATM5kNviDIO#/"
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		isURI(testStr)
+	}
+}
+
+// BenchmarkJoinStrings benchmarks the joinStrings function performance.
+func BenchmarkJoinStrings(b *testing.B) {
+	strs := []string{"markdown", "md", "docx", "word", "pdf", "html"}
+	separator := ", "
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		joinStrings(strs, separator)
+	}
+}
+
+// TestRunWithInsufficientArgs tests the run function with insufficient command-line arguments.
+func TestRunWithInsufficientArgs(t *testing.T) {
+	tests := []struct {
+		name string
+		args []string
+	}{
+		{
+			name: "no arguments",
+			args: []string{"articulate-parser"},
+		},
+		{
+			name: "one argument",
+			args: []string{"articulate-parser", "source"},
+		},
+		{
+			name: "two arguments",
+			args: []string{"articulate-parser", "source", "format"},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Capture stdout
+			oldStdout := os.Stdout
+			r, w, _ := os.Pipe()
+			os.Stdout = w
+
+			// Run the function
+			exitCode := run(tt.args)
+
+			// Restore stdout
+			w.Close()
+			os.Stdout = oldStdout
+
+			// Read captured output
+			var buf bytes.Buffer
+			io.Copy(&buf, r)
+			output := buf.String()
+
+			// Verify exit code
+			if exitCode != 1 {
+				t.Errorf("Expected exit code 1, got %d", exitCode)
+			}
+
+			// Verify usage message is displayed
+			if !strings.Contains(output, "Usage:") {
+				t.Errorf("Expected usage message in output, got: %s", output)
+			}
+
+			if !strings.Contains(output, "export format") {
+				t.Errorf("Expected format information in output, got: %s", output)
+			}
+		})
+	}
+}
+
+// TestRunWithInvalidFile tests the run function with a non-existent file.
+func TestRunWithInvalidFile(t *testing.T) {
+	// Capture stdout and stderr
+	oldStdout := os.Stdout
+	oldStderr := os.Stderr
+	
+	stdoutR, stdoutW, _ := os.Pipe()
+	stderrR, stderrW, _ := os.Pipe()
+	
+	os.Stdout = stdoutW
+	os.Stderr = stderrW
+
+	// Also need to redirect log output
+	oldLogOutput := log.Writer()
+	log.SetOutput(stderrW)
+
+	// Run with non-existent file
+	args := []string{"articulate-parser", "nonexistent-file.json", "markdown", "output.md"}
+	exitCode := run(args)
+
+	// Restore stdout/stderr and log output
+	stdoutW.Close()
+	stderrW.Close()
+	os.Stdout = oldStdout
+	os.Stderr = oldStderr
+	log.SetOutput(oldLogOutput)
+
+	// Read captured output
+	var stdoutBuf, stderrBuf bytes.Buffer
+	io.Copy(&stdoutBuf, stdoutR)
+	io.Copy(&stderrBuf, stderrR)
+	
+	stdoutR.Close()
+	stderrR.Close()
+
+	// Verify exit code
+	if exitCode != 1 {
+		t.Errorf("Expected exit code 1 for non-existent file, got %d", exitCode)
+	}
+
+	// Should have error output
+	errorOutput := stderrBuf.String()
+	if !strings.Contains(errorOutput, "Error processing course") {
+		t.Errorf("Expected error message about processing course, got: %s", errorOutput)
+	}
+}
+
+// TestRunWithInvalidURI tests the run function with an invalid URI.
+func TestRunWithInvalidURI(t *testing.T) {
+	// Capture stdout and stderr
+	oldStdout := os.Stdout
+	oldStderr := os.Stderr
+	
+	stdoutR, stdoutW, _ := os.Pipe()
+	stderrR, stderrW, _ := os.Pipe()
+	
+	os.Stdout = stdoutW
+	os.Stderr = stderrW
+
+	// Also need to redirect log output
+	oldLogOutput := log.Writer()
+	log.SetOutput(stderrW)
+
+	// Run with invalid URI (will fail because we can't actually fetch)
+	args := []string{"articulate-parser", "https://example.com/invalid", "markdown", "output.md"}
+	exitCode := run(args)
+
+	// Restore stdout/stderr and log output
+	stdoutW.Close()
+	stderrW.Close()
+	os.Stdout = oldStdout
+	os.Stderr = oldStderr
+	log.SetOutput(oldLogOutput)
+
+	// Read captured output
+	var stdoutBuf, stderrBuf bytes.Buffer
+	io.Copy(&stdoutBuf, stdoutR)
+	io.Copy(&stderrBuf, stderrR)
+	
+	stdoutR.Close()
+	stderrR.Close()
+
+	// Should fail because the URI is invalid/unreachable
+	if exitCode != 1 {
+		t.Errorf("Expected failure (exit code 1) for invalid URI, got %d", exitCode)
+	}
+
+	// Should have error output
+	errorOutput := stderrBuf.String()
+	if !strings.Contains(errorOutput, "Error processing course") {
+		t.Errorf("Expected error message about processing course, got: %s", errorOutput)
+	}
+}
+
+// TestRunWithValidJSONFile tests the run function with a valid JSON file.
+func TestRunWithValidJSONFile(t *testing.T) {
+	// Create a temporary test JSON file
+	testContent := `{
+		"title": "Test Course",
+		"lessons": [
+			{
+				"id": "lesson1",
+				"title": "Test Lesson",
+				"blocks": [
+					{
+						"type": "text",
+						"id": "block1",
+						"data": {
+							"text": "Test content"
+						}
+					}
+				]
+			}
+		]
+	}`
+
+	tmpFile, err := os.CreateTemp("", "test-course-*.json")
+	if err != nil {
+		t.Fatalf("Failed to create temp file: %v", err)
+	}
+	defer os.Remove(tmpFile.Name())
+
+	if _, err := tmpFile.WriteString(testContent); err != nil {
+		t.Fatalf("Failed to write test content: %v", err)
+	}
+	tmpFile.Close()
+
+	// Test successful run with valid file
+	outputFile := "test-output.md"
+	defer os.Remove(outputFile)
+
+	// Save original stdout
+	originalStdout := os.Stdout
+	defer func() { os.Stdout = originalStdout }()
+
+	// Capture stdout
+	r, w, _ := os.Pipe()
+	os.Stdout = w
+
+	args := []string{"articulate-parser", tmpFile.Name(), "markdown", outputFile}
+	exitCode := run(args)
+
+	// Close write end and restore stdout
+	w.Close()
+	os.Stdout = originalStdout
+
+	// Read captured output
+	var buf bytes.Buffer
+	io.Copy(&buf, r)
+	output := buf.String()
+
+	// Verify successful execution
+	if exitCode != 0 {
+		t.Errorf("Expected successful execution (exit code 0), got %d", exitCode)
+	}
+
+	// Verify success message
+	expectedMsg := fmt.Sprintf("Successfully exported course to %s", outputFile)
+	if !strings.Contains(output, expectedMsg) {
+		t.Errorf("Expected success message '%s' in output, got: %s", expectedMsg, output)
+	}
+
+	// Verify output file was created
+	if _, err := os.Stat(outputFile); os.IsNotExist(err) {
+		t.Errorf("Expected output file %s to be created", outputFile)
+	}
+}
+
+// TestRunIntegration tests the run function with different output formats using sample file.
+func TestRunIntegration(t *testing.T) {
+	// Skip if sample file doesn't exist
+	if _, err := os.Stat("articulate-sample.json"); os.IsNotExist(err) {
+		t.Skip("Skipping integration test: articulate-sample.json not found")
+	}
+
+	formats := []struct {
+		format string
+		output string
+	}{
+		{"markdown", "test-output.md"},
+		{"html", "test-output.html"},
+		{"docx", "test-output.docx"},
+	}
+
+	for _, format := range formats {
+		t.Run("format_"+format.format, func(t *testing.T) {
+			// Capture stdout
+			oldStdout := os.Stdout
+			r, w, _ := os.Pipe()
+			os.Stdout = w
+
+			// Run the function
+			args := []string{"articulate-parser", "articulate-sample.json", format.format, format.output}
+			exitCode := run(args)
+
+			// Restore stdout
+			w.Close()
+			os.Stdout = oldStdout
+
+			// Read captured output
+			var buf bytes.Buffer
+			io.Copy(&buf, r)
+			output := buf.String()
+
+			// Clean up test file
+			defer os.Remove(format.output)
+
+			// Verify successful execution
+			if exitCode != 0 {
+				t.Errorf("Expected successful execution (exit code 0), got %d", exitCode)
+			}
+
+			// Verify success message
+			expectedMsg := "Successfully exported course to " + format.output
+			if !strings.Contains(output, expectedMsg) {
+				t.Errorf("Expected success message '%s' in output, got: %s", expectedMsg, output)
+			}
+
+			// Verify output file was created
+			if _, err := os.Stat(format.output); os.IsNotExist(err) {
+				t.Errorf("Expected output file %s to be created", format.output)
+			}
+		})
+	}
+}
+
+// TestMainFunction tests that the main function exists and is properly structured.
+// We can't test os.Exit behavior directly, but we can verify the main function
+// calls the run function correctly by testing run function behavior.
+func TestMainFunction(t *testing.T) {
+	// Test that insufficient args return exit code 1
+	exitCode := run([]string{"program"})
+	if exitCode != 1 {
+		t.Errorf("Expected run to return exit code 1 for insufficient args, got %d", exitCode)
+	}
+
+	// Test that main function exists (this is mainly for coverage)
+	// The main function just calls os.Exit(run(os.Args)), which we can't test directly
+	// but we've tested the run function thoroughly above.
+}
--- a/scripts/build.ps1
+++ b/scripts/build.ps1
@ -531,6 +531,11 @@ try {
 	if ($Failed -gt 0) {
 		exit 1
 	}
+
+	# Clean up environment variables to avoid contaminating future builds
+	Remove-Item Env:GOOS -ErrorAction SilentlyContinue
+	Remove-Item Env:GOARCH -ErrorAction SilentlyContinue
+	Remove-Item Env:CGO_ENABLED -ErrorAction SilentlyContinue
 } finally {
 	Pop-Location
 }
--- a/scripts/build.sh
+++ b/scripts/build.sh
@ -217,6 +217,14 @@ if [ "$SHOW_TARGETS" = true ]; then
    exit 0
 fi

+# Validate Go installation
+if ! command -v go >/dev/null 2>&1; then
+    echo "Error: Go is not installed or not in PATH"
+    echo "Please install Go from https://golang.org/dl/"
+    echo "Or if running on Windows, use the PowerShell script: scripts\\build.ps1"
+    exit 1
+fi
+
 # Validate entry point exists
 if [ ! -f "$ENTRYPOINT" ]; then
    echo "Error: Entry point file '$ENTRYPOINT' does not exist"
@ -315,7 +323,7 @@ for idx in "${!TARGETS[@]}"; do
        fi
        build_cmd+=("${GO_BUILD_FLAGS_ARRAY[@]}" -o "$OUTDIR/$BIN" "$ENTRYPOINT")

-        if CGO_ENABLED=1 GOOS="$os" GOARCH="$arch" "${build_cmd[@]}" 2>"$OUTDIR/$BIN.log"; then
+        if CGO_ENABLED=0 GOOS="$os" GOARCH="$arch" "${build_cmd[@]}" 2>"$OUTDIR/$BIN.log"; then
            update_status $((idx + 1)) '✔' "$BIN done"
            rm -f "$OUTDIR/$BIN.log"
        else
@ -356,3 +364,6 @@ if [ "$VERBOSE" = true ]; then
    echo "  ────────────────────────────────────────────────"
    printf "  Total: %d/%d successful, %s total size\n" "$success_count" "${#TARGETS[@]}" "$(numfmt --to=iec-i --suffix=B $total_size 2>/dev/null || echo "${total_size} bytes")"
 fi
+
+# Clean up environment variables to avoid contaminating future builds
+unset GOOS GOARCH CGO_ENABLED
Author	SHA1	Message	Date
Kaj Kowalski	1c1460ff04	Refactors main function and enhances test suite Refactors the main function for improved testability by extracting the core logic into a new run function. Updates argument handling and error reporting to use return codes instead of os.Exit. Adds comprehensive test coverage for main functionality, including integration tests and validation against edge cases. Enhances README with updated code coverage and feature improvement lists. Addresses improved maintainability and testability of the application. Bumps version to 0.3.1	2025-05-28 14:23:56 +02:00
Kaj Kowalski	1b945ca2bc	Updates version and improves diagram styling Bumps application version to 0.3.0 for new features or fixes. Enhances README diagram styling for better readability in both light and dark GitHub themes by adjusting colors and adding text color contrast.	2025-05-28 13:26:33 +02:00
Kaj Kowalski	fb343f9a23	Merge pull request #2 Merge pull request #2: Add HTML export functionality and fix build system cross-compilation issues	2025-05-28 13:23:45 +02:00
Kaj Kowalski	ce5b5c20bb	Enhances README and script improvements Updates README to include HTML format, architecture overview, and comprehensive feature descriptions. Improves build scripts by adding cleanup of environment variables and validating Go installation, reducing cross-platform build issues. Fixes README inconsistencies and improves script reliability.	2025-05-28 13:17:08 +02:00
Kaj Kowalski	cc11d2fd84	feat: Add HTML export functionality and GitHub workflow - Implement HTMLExporter with professional styling and embedded CSS - Add comprehensive test suite for HTML export functionality - Update factory to support HTML format ('html' and 'htm') - Add autofix.ci GitHub workflow for code formatting - Support all content types: text, lists, quizzes, multimedia, etc. - Include proper HTML escaping for security - Add benchmark tests for performance validation	2025-05-28 13:00:27 +02:00
Kaj Kowalski	b01260e765	Add comprehensive unit tests for services and main package - Implement tests for the app service, including course processing from file and URI. - Create mock implementations for CourseParser and Exporter to facilitate testing. - Add tests for HTML cleaner service to validate HTML content cleaning functionality. - Develop tests for the parser service, covering course fetching and loading from files. - Introduce tests for utility functions in the main package, ensuring URI validation and string joining. - Include benchmarks for performance evaluation of key functions.	2025-05-25 15:46:10 +02:00