aaa-pattern.md

AAA Pattern (Arrange-Act-Assert)

All tests should follow the AAA pattern, also known as Given-When-Then:

• Arrange (Given): Set up the test data and preconditions
• Act (When): Execute the behavior being tested
• Assert (Then): Verify the expected outcome

This pattern makes tests:

• Easy to read and understand
• Clear about what is being tested
• Simple to maintain and modify

Example

#[test]
fn it_should_create_ansible_host_with_valid_ipv4() {
    // Arrange: Set up test data
    let ip = IpAddr::V4(Ipv4Addr::new(192, 168, 1, 1));

    // Act: Execute the behavior
    let host = AnsibleHost::new(ip);

    // Assert: Verify the outcome
    assert_eq!(host.as_ip_addr(), &ip);
}

Benefits

• Clarity: Each section has a clear purpose
• Structure: Consistent test organization across the codebase
• Debugging: Easy to identify which phase is failing
• Maintenance: Simple to modify specific parts of the test