feat: add Jest tests and migrate to pnpm

[bensabic]

• Install jest as dev dependency
• Add test script to package.json
• Create unit tests for storage.js
• Verify tests pass

@bentossell @factory-ben

[factory-ben]

@droid review

[github-actions]

Code Review: feat: add Jest tests and migrate to pnpm

✅ Overall Assessment

This is a solid PR that adds Jest testing infrastructure and migrates the package manager from npm to pnpm. The tests pass and the changes are well-organized.

👍 What's Good

1. Test Coverage: Good coverage of the storage.js module with tests for filterNewItems, saveFeed, and initStorage
2. Clean Mocking: Proper use of jest.mock for fs operations
3. Documentation Updates: All docs (AGENTS.md, CONTRIBUTING.md, README.md) updated consistently from npm to pnpm
4. CI/CD: GitHub Actions workflow properly updated to use pnpm with pnpm/action-setup@v4

🔧 Suggestions for Improvement

1. Unused imports in test file (minor):

   • path is imported but never used
   • saveSeen and loadFeed are imported but not tested

2. Missing test for loadFeed: The function is imported but has no tests. Consider adding a test case.

3. Missing test for loadSeen: This function isn't even imported but should be tested.

4. Missing test for saveSeen: Imported but not tested.

5. Edge case coverage: Consider adding tests for:

   • Empty array input to filterNewItems
   • saveFeed with less than 100 items (to ensure no trimming issues)
   • Error handling paths in storage functions

📝 Code Snippet Issue

In the test file, there's an unused import that could be cleaned up:

// Line 1-2: fs and path are imported but only fs is used via jest.mock
const fs = require('fs').promises;  // Used (for mock reference)
const path = require('path');        // Not used - can be removed

✅ Approval

The PR is ready to merge as-is. The suggestions above are optional improvements that could be addressed in a follow-up PR.

All 5 tests pass:

• filterNewItems - 3 tests ✓
• saveFeed - 1 test ✓
• initStorage - 1 test ✓