---

name: test-runner description: "Know exactly what failed, where, and why. No output parsing." allowed-tools: mcp__test-runner__run_tests, mcp__test-runner__get_test_failures, mcp__test-runner__list_test_files, mcp__test-runner__rerun_failed, mcp__test-runner__find_tests_for, mcp__test-runner__run_related_tests

test-runner

Tests that tell you WHAT failed, WHERE (with source maps), and WHY (expected vs actual).

First: run_tests

After any code change:

Copyrun_tests({})

Why This Wins

Quick Reference

Common Workflows

Smart Edit-Test Cycle (Recommended)

Copy// BEFORE editing - know what tests exist
find_tests_for({ source_file: 'src/api.ts' })

// ... make your changes ...

// AFTER editing - run only the relevant tests (fast!)
run_related_tests({ source_file: 'src/api.ts' })

Why this workflow?

• find_tests_for tells you what's covered BEFORE you edit
• run_related_tests is faster than run_tests({}) - only runs relevant tests
• Multiple discovery strategies: naming convention, import analysis, co-location

After Making Changes

Copyrun_tests({})

Fixing Failing Tests

Copyrun_tests({})
get_test_failures({})  // Shows expected vs actual, source locations
// ... fix code ...
rerun_failed({})  // Verify fix without running all tests

Run Specific Tests

Copyrun_tests({ files: ['src/auth.test.ts'] })
run_tests({ testNamePattern: 'should validate' })

Targeted Testing After Edits

Copy// Edited server.ts? Find and run its tests:
run_related_tests({ source_file: 'src/server.ts' })

Integration

Run run_tests after using syntax.edit_symbol and types.get_diagnostics to verify behavior unchanged.

Supports

Vitest, Jest (auto-detected)