Vitest Extension Testing

Vitest Extension Testing

Use when running, debugging, or interpreting Vitest test results in the claude-skills-deployer extension (extension/ directory).

Test File Naming Conventions

Common Failures and Fixes

Cannot find module 'vscode' Extension tests mock the vscode API. If this fires unexpectedly, check src/test/ for the mock setup.

Cannot find module './foo' Run npm run compile first — the .ts files must be compiled before Vitest can resolve them via the tsconfig paths.

xvfb-run: not found (Linux/WSL)

sudo apt-get install -y xvfb

Bench p95 regression Benchmarks in *.bench.test.ts report min / avg / p95 / max. A p95 regression (>50ms for read_file, >200ms for tools/list) usually indicates blocking I/O or a synchronous loop in the hot path of index.js.

Parallel timeout in *.solo.test.ts These tests must run with --pool=forks to prevent shared state corruption. If they timeout in the default thread pool, run:

npx vitest run --pool=forks src/foo.solo.test.ts

ENOENT on temp dir after test afterAll cleanup with fs.rmSync(dir, { recursive: true, force: true }) — ensure tmpDir is created in beforeAll not at module level.

Run Commands

# All unit tests (fastest feedback loop)
cd extension && npm test

# Single file
npx vitest run src/mcpUsageLog.test.ts

# Benchmark (spawns MCP server subprocess)
npx vitest run src/mcpFilesystemServer.bench.test.ts

# Integration (VS Code Extension Host — requires display)
npm run test:integration                    # Windows
xvfb-run -a npm run test:integration       # Linux/WSL/CI

Test Coverage Hotspots

Files with the most test coverage to check when refactoring:

• src/mcpUsageLog.ts — mcpUsageLog.test.ts
• src/skillLifecycle.ts — skillLifecycle.test.ts
• src/taskSkillProposals.ts — taskSkillProposals.test.ts
• src/costPipeline.ts — costPipeline.test.ts
• extension/resources/mcp-servers/filesystem/index.js — mcpFilesystemServer.bench.test.ts

Adding a New Test

1. Create src/myModule.test.ts
2. Import from vitest: import { describe, expect, it } from "vitest"
3. Use fs.mkdtempSync for temp dirs; clean up in afterAll
4. Run npm test to confirm it appears in the suite output