test-map

name	test-map
description	Maps source files to their test files so only relevant tests run after a change. Use after modifying source files or when asked which tests cover a file.

Test Map Skill

Purpose

Map test files to source features so Claude can run targeted tests after modifying code, instead of running the full test suite or guessing which tests are relevant.

Activation

• Generate: On first use or when user says "refresh test map"
• Query: After modifying source files, to find which tests to run
• Update: Incrementally when new test files are created

---

How It Works

A compact test-to-feature mapping is maintained at: .claude/idev/test-map/map.json

This maps: feature/source file → [test files that cover it]

---

Phase 1: Detect Test Framework

Auto-detect the testing setup:

JavaScript/TypeScript:
  package.json scripts containing "test" → detect runner
  jest.config.* → Jest
  vitest.config.* → Vitest
  .mocharc.* → Mocha
  karma.conf.* → Karma
  playwright.config.* → Playwright (E2E)
  cypress.config.* → Cypress (E2E)

.NET:
  Glob for *.Tests.csproj or *.Test.csproj → xUnit/NUnit/MSTest
  Read .csproj for <PackageReference Include="xunit|NUnit|MSTest">

Python:
  pytest.ini or pyproject.toml [tool.pytest] → pytest
  Glob for test_*.py or *_test.py

Java:
  src/test/ directory → JUnit
  Glob for *Test.java or *Tests.java

Go:
  Glob for *_test.go → built-in testing

Ruby:
  spec/ directory → RSpec
  test/ directory → Minitest

---

Phase 2: Discover Test Files

Scan for test files using detected patterns:

.NET:
  Glob: **/*.Tests/**/*Test*.cs
  Glob: **/*.Test/**/*Test*.cs
  Convention: {Service}Tests.cs tests {Service}.cs

JavaScript/TypeScript:
  Glob: **/*.test.ts, **/*.test.tsx, **/*.spec.ts, **/*.spec.tsx
  Glob: **/__tests__/**/*.ts
  Convention: {Component}.test.tsx tests {Component}.tsx

Python:
  Glob: **/test_*.py, **/*_test.py
  Glob: tests/**/*.py

Go:
  Glob: **/*_test.go
  Convention: {file}_test.go tests {file}.go

---

Phase 3: Map Tests to Features

By naming convention:

OrderServiceTests.cs → tests OrderService.cs → feature: Orders
OrdersDashboard.test.tsx → tests OrdersDashboard.tsx → feature: Orders

By import analysis:

Read test file imports:
  import { OrderService } from "../../services/OrderService"
  → This test covers OrderService
  → Feature: Orders

By directory structure:

Tests in same feature folder:
  features/Orders/__tests__/ → covers Orders feature

Tests in parallel test project:
  Services.Test/Orders/ → covers Services/Orders/

---

Phase 4: Map Format

Write to .claude/idev/test-map/map.json:

{
  "generated": "YYYY-MM-DD",
  "testFrameworks": {
    "backend": {
      "framework": "xunit|nunit|mstest",
      "testProject": "relative/path/to/test/project",
      "runCommand": "dotnet test path/to/Tests.csproj",
      "runFilteredCommand": "dotnet test --filter {TestClassName}",
      "runSingleCommand": "dotnet test --filter FullyQualifiedName~{TestName}"
    },
    "frontend": {
      "framework": "jest|vitest",
      "runCommand": "npm test -- --watchAll=false",
      "runFilteredCommand": "npm test -- --testPathPattern={pattern} --watchAll=false",
      "runSingleCommand": "npm test -- {testFile} --watchAll=false"
    },
    "e2e": {
      "framework": "playwright|cypress",
      "runCommand": "npx playwright test",
      "runFilteredCommand": "npx playwright test {testFile}"
    }
  },
  "featureToTests": {
    "Orders": {
      "backend": [
        {
          "testFile": "relative/path/to/OrderServiceTests.cs",
          "covers": ["OrderService.cs"],
          "testCount": 12
        }
      ],
      "frontend": [
        {
          "testFile": "relative/path/to/OrdersDashboard.test.tsx",
          "covers": ["OrdersDashboard.tsx"],
          "testCount": 8
        }
      ]
    }
  },
  "sourceToTests": {
    "relative/path/to/OrderService.cs": ["relative/path/to/OrderServiceTests.cs"],
    "relative/path/to/OrdersDashboard.tsx": ["relative/path/to/OrdersDashboard.test.tsx"]
  },
  "untestedFiles": [
    "relative/path/to/file/with/no/tests.ts"
  ]
}

Notes on the format:

• testCount and untestedFiles are OPTIONAL fields — they are expensive to compute and rot quickly. Omit them unless cheap to derive.
• Jest's filter flag is version-dependent: older Jest uses --testPathPattern, newer Jest uses --testPathPatterns. If the filtered command fails, check npx jest --help and update the cached command.

---

Phase 5: Usage

After modifying a source file:

1. Load test-map
2. Look up sourceToTests for the modified file
3. Verify the mapped test file still exists before running it (if missing, update the map)
4. If tests exist → run them with the filtered command
5. Report: "3/3 tests passed" or "1 test failed: ..."

After creating a new feature:

1. Check if test files should be created
2. Suggest test file names following project convention
3. If user wants tests → create them using detected patterns

When user says "run tests":

1. Determine scope:
   - "run tests" → run all tests
   - "run tests for Orders" → use featureToTests mapping
   - "run tests for OrderService" → use sourceToTests mapping
2. Use the appropriate run command from testFrameworks
3. Report results

---

Phase 6: Targeted Test Running

Run only affected tests after a change:

Modified: OrderService.cs
  → sourceToTests → OrderServiceTests.cs
  → Command: dotnet test --filter OrderServiceTests
  → Result in ~10 seconds instead of full suite (~2 minutes)

Run feature tests after multi-file change:

Modified: 5 files in Orders
  → featureToTests.Orders → all test files
  → Command: dotnet test --filter "Namespace~Orders"
  → Result in ~30 seconds instead of full suite

---

Anti-Patterns

1. Do NOT run the full test suite when targeted tests are available
2. Do NOT skip tests after modifying code — always check
3. Do NOT track test-to-test dependencies (only source-to-test)
4. Do NOT include test helper/fixture files in the map
5. Do NOT run E2E tests for unit-level changes