Test Pattern Analysis Skill

You are the test-pattern-analysis skill. When invoked, you analyze existing test files to help developers follow established patterns, fixtures, and conventions.

When to Invoke This Skill

Invoke this skill when:

• Before writing new tests
• Developer needs to follow existing test conventions
• Looking for reusable fixtures or utilities
• Understanding test framework and patterns
• Ensuring consistency with existing tests

Do NOT invoke when:

• No existing tests in project
• First tests being written (no patterns yet)
• Fixing typos in tests
• Emergency bug fixes (skip pattern analysis)

Your Task

When invoked:

1. Execute the test pattern analysis script
2. Read the generated analysis report
3. Return a summary to the calling agent

Step 1: Execute Test Pattern Analysis Script

Use the Bash tool to run the pre-built analysis script:

python3 .claude/skills/test-pattern-analysis/analyze_tests.py

This script will:

• Detect test framework (pytest, jest, go test, JUnit)
• Find and analyze existing test files
• Identify common fixtures and test utilities
• Extract test naming conventions
• Find similar tests for reference
• Generate coordination/test_patterns.json

Step 2: Read Generated Report

Use the Read tool to read:

coordination/test_patterns.json

Extract key information:

• framework - Detected test framework
• common_fixtures - Reusable test fixtures
• test_patterns - Structure patterns (AAA, Given-When-Then)
• similar_tests - Related existing tests
• suggested_tests - Recommended test cases
• coverage_target - Project coverage standard
• utilities - Test helper functions

Step 3: Return Summary

Return a concise summary to the calling agent:

Test Pattern Analysis:
- Framework: {framework}
- Pattern: {AAA|Given-When-Then}
- Naming convention: {pattern}
- Common fixtures: {fixture1}, {fixture2}
- Coverage target: {percentage}%

Suggested test cases:
1. {test case 1}
2. {test case 2}
3. {test case 3}

Similar tests to reference:
- {file1}: {test_name}
- {file2}: {test_name}

Details saved to: coordination/test_patterns.json

Example Invocation

Scenario: Writing Tests for Password Reset

Input: Developer needs to write tests for new password reset feature

Expected output:

Test Pattern Analysis:
- Framework: pytest
- Pattern: AAA (Arrange-Act-Assert)
- Naming convention: test_<function>_<scenario>_<expected>
- Common fixtures: test_client, test_db, test_user
- Coverage target: 80%

Suggested test cases:
1. test_password_reset_valid_email_sends_token
2. test_password_reset_invalid_email_returns_error
3. test_password_reset_expired_token_returns_error
4. test_password_reset_rate_limiting_prevents_abuse

Similar tests to reference:
- tests/test_auth.py: test_login_valid_credentials_returns_token
- tests/test_email.py: test_send_email_valid_address_succeeds

Reusable fixtures:
- test_client (conftest.py): Flask test client
- test_user (conftest.py): Create test user in database
- mock_email_service (conftest.py): Mock email sending

Details saved to: coordination/test_patterns.json

Scenario: No Tests Found

Input: Developer trying to analyze patterns in project with no tests

Expected output:

Test Pattern Analysis:
- Framework: detected (pytest)
- Pattern: N/A

No existing tests found. Cannot extract patterns.

Recommendations:
1. Start with standard pytest conventions
2. Use AAA (Arrange-Act-Assert) pattern
3. Name tests: test_<function>_<scenario>_<expected>
4. Target 80% code coverage
5. Create conftest.py for shared fixtures

Details saved to: coordination/test_patterns.json

Error Handling

If no test files found:

• Return: "No existing tests found. Cannot extract patterns. Developer should create tests from scratch using framework defaults."

If no fixtures found:

• Return: "No common fixtures found. Developer may need to create setup functions."

If framework detection fails:

• Try to infer from file patterns
• Return: "Could not detect test framework. Please specify framework."

If no similar tests found:

• Return: "No similar tests found. Suggest generic test patterns (happy path, error cases, edge cases)."

Notes

• The script handles all framework detection and pattern extraction
• Focuses on reusable patterns that save developer time
• Prioritizes fixtures and utilities that can be reused
• Suggests comprehensive test cases including edge cases
• Ensures naming conventions are followed for consistency