File Path Parser Challenge

Time estimate: 30-45 minutes

Context

This parser extracts file operations from AI coding assistant output. When an AI assistant modifies code, it outputs lines like:

→ Read src/App.tsx
← Edit src/components/Button.tsx
← Create tests/new-test.ts

The parser identifies the operation type (read_file, edit_file, create_file) and extracts the file path.

Why This Matters

In real-world AI-assisted development:

1. Filenames often have spaces - Modern projects use descriptive names like my component.tsx or helper functions.ts
2. Special characters are common - Next.js uses [id] for dynamic routes, legacy folders use (old) notation
3. International teams - Developers use Cyrillic, Chinese, emoji in filenames
4. Quoted paths are standard - Shell commands and AI output quote paths with spaces

This bug causes:

• ❌ Files not being tracked correctly
• ❌ AI edits failing silently
• ❌ Incorrect file operation logs
• ❌ Broken workflows for international teams

Real impact: This parser processes thousands of AI operations daily. Every edge case failure means lost work.

Your Task

Fix the parseFileOperation() function in src/parser.ts to handle these edge cases:

1. Filenames with spaces (quoted)

'← Edit "src/my component.tsx"'     → extract: 'src/my component.tsx'
'→ Read "src/helper functions.ts"'  → extract: 'src/helper functions.ts'

2. Escaped quotes in filenames

'← Edit "src/file\"with\"quotes.tsx"'  → extract: 'src/file"with"quotes.tsx'
'← Edit \'src/user\'s profile.tsx\''   → extract: "src/user's profile.tsx"

3. Mixed quotes

'← Edit "src/\'special\'.tsx"'  → extract: "src/'special'.tsx"

4. Special characters (parentheses, brackets, Unicode)

'← Edit "src/utils (legacy)/helper.ts"'  → extract: 'src/utils (legacy)/helper.ts'
'← Edit "src/[id]/page.tsx"'             → extract: 'src/[id]/page.tsx'
'← Edit "src/файл.tsx"'                  → extract: 'src/файл.tsx'
'← Edit "src/🚀rocket.tsx"'              → extract: 'src/🚀rocket.tsx'

Definition of Done

• All tests in tests/parser.test.ts pass
• Existing functionality preserved (unquoted filenames still work)
• Code is clean and well-commented
• No external dependencies added (use only built-in JavaScript/TypeScript)

Getting Started

# Install dependencies
npm install

# Run tests (many will fail initially)
npm test

# Run tests in watch mode
npm run test:watch

Current Implementation

The current regex patterns in src/parser.ts:

• Arrow format: /^[\u2190<]\s*(?:Edit|Write|Create)\s+(.+)$/i
• Legacy format: /(?:Writing|Editing)\s+['"]?([^\s'"]+)['"]?/i

Problem: [^\s'"]+ stops at the first space or quote, so quoted filenames are truncated.

Constraints

• Time limit: 30-45 minutes
• No external libraries: Use only built-in JavaScript/TypeScript features
• Preserve existing behavior: Unquoted filenames must still work
• All tests must pass: Run npm test to verify

Submission

1. Fork this repository (or clone and create your own repo)
2. Fix the parseFileOperation() function
3. Ensure all tests pass: npm test
4. Commit your changes
5. Share the repository link or create a pull request

Notes

• You can use AI tools (ChatGPT, Claude, etc.) but please add a comment explaining your approach
• Focus on correctness first, then optimize if time permits
• If you get stuck, implement partial solution and document what's missing

Tech Stack

• Language: TypeScript
• Test Framework: Vitest
• Node.js: 20+

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Good luck! 🚀

This challenge is part of the agiens/join coding challenges.