name: "Test Design Patterns" description: "Apply testing patterns like AAA (Arrange-Act-Assert), mocking, fixtures, and parameterization for maintainable test suites" category: "testing" required_tools: ["Read", "Write", "Bash"]

Test Design Patterns

Purpose

Apply proven testing patterns to create maintainable, reliable test suites that effectively validate functionality.

When to Use

• Writing unit, integration, or system tests
• Organizing test code
• Creating test fixtures and data
• Designing test strategies

Key Capabilities

1. AAA Pattern - Arrange-Act-Assert structure
2. Test Fixtures - Reusable test data and setup
3. Mocking/Stubbing - Isolate units under test

Approach

1. Arrange: Set up test data and conditions
2. Act: Execute the code being tested
3. Assert: Verify expected outcomes
4. Use descriptive test names
5. Keep tests independent and isolated

Example

Context: Testing a task creation function

def test_add_task_with_valid_input_creates_task():
    # Arrange
    queue = TaskQueue()
    task_data = {"title": "Test", "agent": "tester"}
    
    # Act
    task_id = queue.add_task(task_data)
    
    # Assert
    assert task_id is not None
    assert queue.get_task(task_id).title == "Test"

Best Practices

• ✅ One logical assertion per test
• ✅ Descriptive test names explaining scenario
• ✅ Independent tests (no shared state)
• ❌ Avoid: Testing multiple unrelated things together