Refactor error payload logic

tests/formatError.test.ts

@@ -0,0 +1,23 @@
+import { test } from 'node:test';
+import assert from 'node:assert';
+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);
+  assert.ok('stack' in payload);
+});
+
+test('omits stack in production', () => {
+  process.env.NODE_ENV = 'production';
+  const err = new Error('boom');
+  const payload = formatError(err);
+  assert.ok(!('stack' in payload));
+});
+
+test.after(() => {
+  if (originalEnv === undefined) delete process.env.NODE_ENV; else process.env.NODE_ENV = originalEnv;
+});