inspector/clients/cli/__tests__

CLI Tests

Running Tests

# Run all tests (pretest builds test-servers + the CLI binary)
npm test

# Run all tests under the per-file coverage gate
npm run test:coverage

# Run in watch mode (useful for test file changes)
npm run test:watch

# Run specific test file
npm run test:cli          # cli.test.ts
npm run test:cli-tools   # tools.test.ts
npm run test:cli-headers # headers.test.ts
npm run test:cli-metadata # metadata.test.ts

How the CLI is exercised

Most tests run the CLI in-process: helpers/cli-runner.ts imports runCli() from ../src/cli.ts and invokes it directly, capturing process.stdout/stderr and mapping thrown errors to an exit code. This is what lets vitest's v8 coverage instrument clients/cli/src (#1484). Because commander uses .exitOverride(), a parse/usage error throws instead of calling process.exit and tearing down the worker.

e2e.test.ts is the deliberately thin out-of-process layer: it spawns the built build/index.js as a real subprocess to cover the shebang, the index.ts isMain bootstrap, and the actual process.exit codes — the only parts the in-process runner can't reach. (scripts/smoke-cli.mjs at the repo root provides a further end-to-end check of the binary.)

Test Files

• cli.test.ts - Basic CLI functionality: CLI mode, environment variables, config files, resources, prompts, logging, transport types
• tools.test.ts - Tool-related tests: Tool discovery, JSON argument parsing, error handling, prompts
• headers.test.ts - Header parsing and validation
• metadata.test.ts - Metadata functionality: General metadata, tool-specific metadata, parsing, merging, validation
• methods.test.ts - Method/option-validation paths not covered elsewhere (resource templates, missing/invalid options, the -- target separator)
• error-handler.test.ts - The binary's handleError error sink, exercised in-process with process.exit stubbed
• e2e.test.ts - Out-of-process spawn of the built binary (exit codes + boot)

Helpers

The helpers/ directory contains shared utilities:

• cli-runner.ts - Invokes runCli() in-process and captures stdout/stderr + exit code
• assertions.ts - Custom assertion helpers for CLI output validation
• fixtures.ts - Test config/catalog file generators and temporary directory management

HTTP/SSE test servers (for transport tests) come from the @modelcontextprotocol/inspector-test-server package (createTestServerHttp), and the bundled stdio server is launched via getTestMcpServerCommand().

Notes

• Test files run in separate forked processes (pool: 'forks'), so the in-process runner's process.std*.write patching never overlaps across files; tests within a file run sequentially
• Config files use crypto.randomUUID() for uniqueness
• HTTP/SSE servers use dynamic port allocation to avoid conflicts
• Coverage is enforced per-file (lines ≥ 90, statements ≥ 85, functions ≥ 80, branches ≥ 50). src/index.ts (the binary bootstrap) is excluded because it only runs in the spawned binary, which coverage can't instrument
• All tests use the built-in MCP test servers — no external/registry dependencies