grammarly-mcp: Instructions file for Claude Code

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Commands

pnpm build          # Compile TypeScript to dist/
pnpm start          # Run the MCP server (requires env vars)
pnpm type-check     # TypeScript type checking only
pnpm biome:check    # Lint + format check (no writes)
pnpm biome:fix      # Auto-fix lint + format issues
pnpm check-all      # Run type-check && biome:check

# Testing
pnpm test           # Run tests in watch mode
pnpm test:run       # Run tests once
pnpm test:coverage  # Run tests with coverage report
pnpm test:unit      # Run unit tests only
pnpm test:integration  # Run integration tests (forks pool)
pnpm test:ci        # CI mode with coverage + JSON reporter

Testing

Framework: Vitest with V8 coverage provider.

Coverage thresholds (enforced in CI):

• Lines: 85%
• Functions: 85%
• Branches: 75%
• Statements: 85%

Test structure:

tests/
├── setup.ts              # Global test setup
├── unit/                 # Fast, isolated unit tests
│   ├── config.test.ts
│   ├── server.test.ts
│   ├── schemas.test.ts
│   ├── grammarlyOptimizer.test.ts
│   ├── browser/
│   │   ├── provider.test.ts
│   │   ├── browserUseProvider.test.ts
│   │   ├── grammarlyTask.test.ts
│   │   └── stagehand/
│   │       ├── sessionManager.test.ts
│   │       ├── stagehandProvider.test.ts
│   │       └── grammarlyTask.test.ts
│   └── llm/
│       ├── rewriteClient.test.ts
│       └── stagehandLlm.test.ts
└── integration/          # Tests requiring more isolation
    └── stagehandProvider.test.ts

Mock patterns:

• Use vi.mock() for module mocks; import after mocking
• Use vi.fn() for function mocks with mockResolvedValue/mockRejectedValue
• Use vi.useFakeTimers() for retry/backoff tests
• Stub setTimeout globally to skip sleep() delays in Stagehand tests

Key conventions:

• All tests are synchronous by default; async only when awaiting promises
• Mock at module boundaries (SDK clients, external services)
• Use test.each() for parameterized edge cases
• Attach catch handlers before advancing fake timers to prevent unhandled rejections