Test Doubles Mocking (Symfony)

Use when

• Building regression-safe behavior with TDD/functional/e2e tests.
• Converting bug reports into executable failing tests.

Default workflow

1. Write failing test for target behavior and one boundary case.
2. Implement minimal code to pass.
3. Refactor while preserving green suite.
4. Broaden coverage for invalid/unauthorized/not-found paths.

Guardrails

• Prefer deterministic fixtures/builders.
• Assert observable behavior, not internal implementation.
• Keep tests isolated and stable in CI.