MCP Printer Server

# MCP Printer Tests Unit tests for the MCP Printer server, focusing on pure functions, configuration parsing, and security validation. ## Running Tests ```bash # Run tests once pnpm test # Run tests in watch mode (re-runs on file changes) pnpm test:watch # Open Vitest UI (browser-based test interface) pnpm test:ui # Run tests with coverage report pnpm test:coverage ``` ## Test Structure ### Unit Tests (`tests/unit/`) - **`utils.test.ts`** - Pure utility functions - String parsing (`parseDelimitedString`) - Language mapping (`getLanguageFromExtension`) - HTML manipulation (`fixMultilineSpans`) - Response formatting (`formatPrintResponse`) - **`file-detection.test.ts`** - File type detection logic - Markdown rendering detection (`shouldRenderToPdf`) - Code syntax highlighting detection (`shouldRenderCode`) - Extension handling and exclusions - **`security.test.ts`** - Security validation - File path validation (`validateFilePath`) - Allowed/denied path enforcement - .env file blocking - Sensitive directory protection - **`config.test.ts`** - Configuration parsing - Environment variable parsing - Default values - Boolean/array/path parsing - Configuration merging ## Coverage Goals Current coverage targets (unit tests only): - ✅ Pure functions: 90%+ coverage - ✅ Security validation: High coverage on critical paths - ✅ Configuration parsing: 100% coverage Note: Integration-heavy code (server, tools, renderers) that depends on external systems (CUPS, Chrome, pandoc) is intentionally excluded from unit tests. ## Future Enhancements Potential additions for comprehensive testing: 1. **Integration tests** - Mock external commands (lpr, lpstat, pandoc, chrome) 2. **Renderer tests** - Test markdown and code PDF generation with mocked Chrome 3. **Tool tests** - Test MCP tool implementations with mocked CUPS commands ## Test Helpers The `tests/helpers/` directory is available for shared test utilities as the test suite grows. Temporary test files are written to `tests/tmp/` (not tracked in git).