test-suite-prioritizer

Test Suite Prioritizer

Intelligently prioritize test execution based on code changes and project impact.

Core Capabilities

This skill helps optimize test execution by:

1. Analyzing code changes - Identifying which files were modified
2. Mapping test coverage - Determining which tests cover changed code
3. Calculating priority scores - Ranking tests by impact and relevance
4. Generating execution order - Creating an optimized test run sequence
5. Providing reasoning - Explaining why each test is prioritized

Test Prioritization Workflow

Step 1: Identify Code Changes

Determine what code has been modified to focus testing efforts.

Sources of Change Information:

• Git diff (most recent commit or uncommitted changes)
• Pull request file list
• Specific files mentioned by user
• Modified files in working directory

Collect Changed Files:

# Recent commit changes
git diff --name-only HEAD~1 HEAD

# Uncommitted changes
git diff --name-only

# Changes in current branch vs main
git diff --name-only main...HEAD

# Files in last N commits
git diff --name-only HEAD~N HEAD

Example Output:

src/auth/login.py
src/payment/processor.py
src/models/user.py
tests/test_auth.py

Step 2: Analyze Test Coverage

Map which tests cover the changed code.

Strategies:

1. Direct Test-to-Code Mapping

• Tests in same directory as changed code
• Tests with similar names (e.g., user.py → test_user.py)
• Integration tests that import changed modules

2. Static Analysis

• Parse test files for imports
• Identify which modules each test uses
• Map dependencies transitively

3. Coverage Data (if available)

• Use pytest-cov, coverage.py, JaCoCo output
• Identify tests that execute changed lines
• Most accurate but requires prior test run

Example Mapping:

Changed: src/auth/login.py
Covered by:
  - tests/test_auth.py::test_login_success
  - tests/test_auth.py::test_login_failure
  - tests/integration/test_user_flow.py::test_complete_registration
  - tests/e2e/test_authentication_flow.py::test_full_auth_cycle

Changed: src/payment/processor.py
Covered by:
  - tests/test_payment.py::test_process_payment
  - tests/test_payment.py::test_refund
  - tests/integration/test_checkout.py::test_complete_purchase