Fix error handling to properly use formatError utility and improve environment detection

- Actually use the formatError function in the error handling code
- Update formatError function to accept env parameter for Cloudflare Workers
- Improve environment detection to use WORKER_ENV instead of process.env
- Update tests to match new function signature
- Add comprehensive test coverage for error formatting
- Fix linting issues and ensure proper TypeScript types

tests/formatError.test.ts

@@ -5,19 +5,32 @@ import { formatError } from '../src/utils/error';
 const originalEnv = process.env.NODE_ENV;
 
 test('includes stack when not in production', () => {
-  delete process.env.NODE_ENV;
   const err = new Error('boom');
-  const payload = formatError(err);
+  const payload = formatError(err, { WORKER_ENV: 'development' });
   assert.ok('stack' in payload);
 });
 
 test('omits stack in production', () => {
-  process.env.NODE_ENV = 'production';
   const err = new Error('boom');
-  const payload = formatError(err);
+  const payload = formatError(err, { WORKER_ENV: 'production' });
   assert.ok(!('stack' in payload));
 });
 
+test('includes message for all environments', () => {
+  const err = new Error('boom');
+  const devPayload = formatError(err, { WORKER_ENV: 'development' });
+  const prodPayload = formatError(err, { WORKER_ENV: 'production' });
+  
+  assert.strictEqual(devPayload.message, 'boom');
+  assert.strictEqual(prodPayload.message, 'boom');
+});
+
+test('handles non-Error objects', () => {
+  const payload = formatError('string error', { WORKER_ENV: 'development' });
+  assert.strictEqual(payload.message, 'Unknown error');
+  assert.strictEqual(payload.error, 'Internal Server Error');
+});
+
 test.after(() => {
   if (originalEnv === undefined) delete process.env.NODE_ENV; else process.env.NODE_ENV = originalEnv;
 });