Imported from majiayu000/claude-skill-registry (skills/testing/test-fundamentals/SKILL.md). Install upstream with npx skills add majiayu000/claude-skill-registry --skill test-fundamentals. Copyright stays with the author.

Testing Core Rules

General testing principles that apply to ALL tests (unit and integration).

See code-comment-style skill for comment guidelines

🚨 CRITICAL RULES (Immediate Failure)

1. Zero Test Failure Tolerance

🚨 CRITICAL: ANY existing test failure STOPS the update process

• ANY existing test failure STOPS the update process
• NO excuses for test failures
• Determine cause and fix immediately
• Never disable or skip tests to proceed

RULE: Before starting any work, run existing tests and ensure they ALL pass.

# Check current state
npm run test

# If ANY test fails:
# 1. STOP all work
# 2. Analyze the failure
# 3. Fix the implementation
# 4. Re-run tests until ALL pass

Why:

• Prevents introducing new bugs
• Maintains code quality
• Ensures reliable baseline

2. Test Coverage Requirements

🚨 CRITICAL: ALL new operations MUST have test coverage

• ALL new operations MUST have unit test coverage
• ALL new operations MUST have integration tests
• Integration tests run when credentials available, fail naturally when not
• Never use .skip() on individual tests
• Tests should be written and ready to work

Requirements:

• ✅ Every operation has unit tests
• ✅ Every operation has integration tests
• ✅ Both success and error cases tested
• ✅ 100% pass rate for available tests

Example:

// ✅ CORRECT: Both unit and integration tests
test/unit/UserProducerTest.ts       // Unit test with nock
test/integration/UserProducerTest.ts // Integration test with real API

// ❌ WRONG: Only one test type
test/unit/UserProducerTest.ts       // Missing integration test

3. Test Preservation

🚨 CRITICAL: EXISTING tests must pass throughout entire workflow

• EXISTING tests must pass throughout entire workflow
• NEVER modify existing tests during updates
• Add new tests separately

Why:

• Prevents breaking existing functionality
• Maintains test suite integrity
• Ensures backward compatibility

Exceptions: Only in 'fix' workflow when API has breaking changes (see Exceptions section)

4. API Validation Before Implementation

🚨 CRITICAL: Test every operation with curl/Node.js FIRST

Before implementing any operation:

1. Test with curl or Node.js script
2. Capture real API responses
3. Save as test fixtures
4. Verify credentials work

# Example: Test API endpoint before implementing
curl -X GET "https://api.example.com/users/123" \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json"

# Capture response, sanitize PII, save as fixture
# THEN implement the operation

Why:

• Verifies API works as documented
• Captures real response structure
• Identifies auth issues early
• Provides fixtures for unit tests

5. Test Failure Resolution Protocol

🚨 CRITICAL: MANDATORY when tests fail

When tests fail, follow this protocol:

1. ANALYZE the failure - understand why
2. FIX THE IMPLEMENTATION - correct bugs in src/
3. NEVER SKIP TESTS - no .skip(), .only(), or comments
4. NEVER MODIFY GENERATED FILES
5. RE-RUN TESTS - execute until ALL pass
6. REPEAT UNTIL ZERO FAILURES

PROHIBITED:

• Using .skip() on individual tests
• Using .only() to run only passing tests
• Commenting out failing tests
• Accepting any failures as "expected"
• Modifying test expectations to match wrong behavior

Required Pass Rates:

• Unit Tests: 100% pass rate
• Integration Tests: 100% when credentials available
• Lint: Zero errors, zero warnings
• Build: Exit code 0

Example of CORRECT approach:

// Test fails: expected 'John' but got 'John Doe'

// ❌ WRONG: Skip the test
it.skip('should get user name', async () => { ... });

// ❌ WRONG: Change expectation
expect(user.name).to.equal('John Doe'); // Changed to match wrong output

// ✅ CORRECT: Fix the implementation
// Fix the mapping in src/Mappers.ts to extract first name correctly
// Re-run test until it passes

🟡 STANDARD RULES

Test Naming

Use descriptive test names explaining the scenario:

// ✅ GOOD - Clear, specific
it('should retrieve user by ID with correct type mapping', async () => { ... });
it('should throw NoSuchObjectError when user not found', async () => { ... });
it('should map email string to Email type', async () => { ... });

// ❌ BAD - Vague, unclear
it('should work', async () => { ... });
it('test get user', async () => { ... });

Use 'should' for expected behaviors:

• ✅ "should retrieve user by ID"
• ✅ "should throw error when invalid ID"
• ✅ "should map API response to core types"

Include failure cases:

• ✅ "should throw error when user not found"
• ✅ "should handle authentication failure"
• ✅ "should return empty array when no results"

Test Execution Order

Run tests in this order:

1. Unit tests first (fast feedback)

   npm run test:unit

2. Integration tests with credentials

   npm run test:integration

3. Lint and build

   npm run lint
   npm run build

4. All must pass for task completion

Why this order:

• Unit tests are fast, catch most issues
• Integration tests verify real API behavior
• Lint catches style issues
• Build verifies TypeScript compilation

Test Structure

Standard describe/it structure:

describe('{ClassName}', () => {
  describe('{methodName}', () => {
    it('should {expected behavior}', async () => {
      // Arrange - Set up test data
      // Act - Execute the method
      // Assert - Verify the result
    });

    it('should {handle error case}', async () => {
      // Arrange - Set up error condition
      // Act - Execute the method
      // Assert - Verify error handling
    });
  });
});

Key elements:

• ✅ Outer describe for class/module
• ✅ Inner describe for method
• ✅ Multiple it() for different scenarios
• ✅ Arrange/Act/Assert pattern

🟡 STANDARD RULES

Debug Logging (MANDATORY for Integration Tests)

ALL integration tests MUST include debug logging to enable:

• Runtime mapper validation
• Test failure debugging
• API response verification

Standard Pattern:

import { getLogger } from '@auditmation/util-logger';

const logger = getLogger('console', {}, process.env.LOG_LEVEL || 'info');

describe('User Producer Tests', function() {
  it('should list users', async function() {
    const result = await userApi.list(organizationId);

    // MANDATORY: Log operation and result
    logger.debug(`userApi.list(${organizationId})`, JSON.stringify(result, null, 2));

    expect(result).to.not.be.null;
    // ... assertions
  });
});

Requirements:

• ✅ Import logger from @auditmation/util-logger
• ✅ Create logger with LOG_LEVEL from environment
• ✅ Log AFTER every API operation call
• ✅ Include operation name and parameters in log
• ✅ Include full result as JSON.stringify

Visibility:

# Normal run - no debug output
npm run test:integration

# Debug run - full logging
env LOG_LEVEL=debug npm run test:integration

Benefits:

• Enables runtime mapper field validation
• Quick debugging of test failures
• Documents actual API behavior
• Verifies responses match expectations

RULE: Integration tests without debug logging are INCOMPLETE.

🟢 GUIDELINES

Documentation

Document test setup in USERGUIDE.md:

## Testing

### Unit Tests

Unit tests run without credentials and use mocked HTTP interactions:

\`\`\`bash
npm run test:unit
\`\`\`

### Integration Tests

Integration tests require credentials in a `.env` file:

\`\`\`bash
# .env
SERVICE_API_KEY=your-api-key
SERVICE_EMAIL=your-email
SERVICE_PASSWORD=your-password
\`\`\`

Run integration tests:

\`\`\`bash
npm run test:integration

# With debug logging:
LOG_LEVEL=debug npm run test:integration
\`\`\`

### Full Test Suite

Run all tests:

\`\`\`bash
npm test
\`\`\`

Skipped Tests

When tests can be skipped (ONLY for integration test suites):

// ✅ ALLOWED: Skip entire integration suite if no credentials
describe('Service Integration', function () {
  before(function () {
    if (!hasCredentials()) {
      this.skip(); // Skip whole suite
    }
  });
});

// ❌ FORBIDDEN: Skip individual tests
it.skip('should get user', async () => { ... });

Document skipped tests in output:

• Integration tests should log when skipped due to missing credentials
• User should see clear message about how to enable tests

Exceptions

When Tests Can Be Modified

Tests can ONLY be modified in these scenarios:

1. 'fix' workflow (not 'update')

   • When fixing existing bugs
   • When API has breaking changes
   • When correcting incorrect test logic

2. API Breaking Changes

   • When API endpoint changes
   • When response structure changes
   • When authentication method changes

3. Incorrect Test Logic

   • When test expectations were wrong
   • When test setup was incorrect
   • When test assertions don't match requirements

ALWAYS document reason in commit message:

fix: update UserProducer tests for API breaking change

The API changed the user endpoint from /users/:id to /v2/users/:id
and added a required 'version' field in the response.

Updated tests to match new API contract.

Integration Test Exceptions

Integration tests have special skip rules:

• Can skip entire suite if no credentials (using this.skip() in before hook)
• Must document in test output
• Should provide instructions for enabling

before(function () {
  if (!hasCredentials()) {
    console.log('Skipping integration tests: no credentials in .env');
    console.log('Create a .env file with SERVICE_API_KEY to enable');
    this.skip();
  }
});

Validation

Validate general testing rules:

# Check test files exist
ls -lh test/unit/
ls -lh test/integration/

# Run all tests
npm run clean
npm run build
npm run test
npm run test:integration  # If credentials available

# Check for skipped tests (should only be integration suites without creds)
npm test 2>&1 | grep -i "skip"

# Check for test failures (should be none)
npm test 2>&1 | grep -i "fail" && echo "❌ FAIL: Tests failing" || echo "✅ PASS"

# Check build exits with 0
npm run build && echo "✅ PASS: Build successful" || echo "❌ FAIL: Build failed"

# Check lint passes
npm run lint && echo "✅ PASS: Lint successful" || echo "❌ FAIL: Lint failed"

Expected results:

• ✅ All tests pass
• ✅ Only integration suites skip when no credentials
• ✅ No individual tests skipped
• ✅ Build exits with code 0
• ✅ Lint passes with zero errors/warnings

Comment Style for Tests

See code-comment-style skill for complete guidelines

Key Rules for Test Code

NEVER comment obvious assertions:

// ❌ WRONG - Comments restate assertions
// Required fields
expect(entry).to.have.property('id');
expect(entry).to.have.property('name');

// ID should be a string
expect(entry.id).to.be.a('string');

// Validate structure
const groups = groupsResult.items;
expect(groups).to.be.an('array');

// ✅ CORRECT - Assertions are self-documenting
expect(entry).to.have.property('id');
expect(entry).to.have.property('name');
expect(entry.id).to.be.a('string');

const groups = groupsResult.items;
expect(groups).to.be.an('array');

DO comment non-obvious test logic:

// ✅ GOOD - Explains special test case
// Unicode group names require special URL encoding on this endpoint
const result = await groupApi.get(orgId, '测试组');

// ✅ GOOD - Explains API quirk being tested
// API returns 400 for invalid credentials but 404 for missing users
// We normalize both to NotConnectedError for consistent handling
try {
  await userApi.get(invalidUserId);
} catch (error) {
  expect(error).to.be.instanceOf(NotConnectedError);
}

Use Arrange/Act/Assert pattern without comments:

// ❌ WRONG - Structural comments
it('should get user by ID', async () => {
  // Arrange - Set up test data
  const userId = 'test-123';

  // Act - Execute the method
  const result = await userApi.get(orgId, userId);

  // Assert - Verify the result
  expect(result).to.not.be.null;
  expect(result.id).to.equal(userId);
});

// ✅ CORRECT - Blank lines show structure
it('should get user by ID', async () => {
  const userId = 'test-123';

  const result = await userApi.get(orgId, userId);

  expect(result).to.not.be.null;
  expect(result.id).to.equal(userId);
});

Reference: See code-comment-style.md for full guidelines