Test Software

Test contract

• Define the behavior, invariant, or defect before selecting a test layer.
• Use the lowest layer that observes the risk without hiding the integration boundary under test.
• Test behavior rather than private implementation details.
• Avoid snapshots that hide meaningful assertions.
• Do not mock the component whose integration contract is under test.
• Control time, randomness, concurrency, and external dependencies explicitly.
• Keep fixtures minimal and readable.
• Do not “fix” flaky tests by adding blind retries or sleeps.
• Do not claim a regression test without proving it fails against the broken behavior when feasible.
• Treat tests as potentially state-changing: they may write databases, queues, files, snapshots, browsers, or external sandboxes.
• Do not run tests against production, shared customer data, or external services without explicit authorization and a verified isolation strategy.
• Stop when the configured test target or cleanup behavior is ambiguous.