# Project Conventions

## Language
- TypeScript strict mode, no `any` types
- Prefer const over let, never use var
- Use template literals over string concatenation

## Architecture
- Feature-based folder structure under src/features/
- Each feature exports through an index.ts barrel file
- Shared utilities go in src/lib/

## Error Handling
- Use Result<T, E> pattern for expected failures
- Throw only for programmer errors
- Always log errors with structured context

## Testing
- Colocate tests next to source files (*.test.ts)
- Use factories for test data, not fixtures
- Integration tests in __tests__/ directories

---
trigger: glob
globs: "**/*.test.ts"
---

# Testing Conventions

- Use Vitest as the test runner
- Colocate test files next to source files
- Use describe blocks organized by function/component name
- Prefer userEvent over fireEvent in component tests
- Mock external services; never hit real APIs in unit tests