Testing Guidelines

This skill treats tests as protection for project-owned behavior, not as a coverage ritual. It favors cheap sans-I/O tests and rejects tests that merely restate test-double configuration, third-party libraries, or transparent wiring.

A meaningful test protects an exact project-owned invariant with an independently derived oracle at a level capable of observing a realistic defect. When the available infrastructure cannot provide that evidence, add no test and record the coverage gap when protection is still required.

Test Admission

Test behavior that the project owns. Assume third-party libraries are correct and already tested.

Add a test only when it can fail because project-owned behavior is wrong.

Before adding or retaining a test, require all of the following:

• Name the exact project-owned invariant that the test protects.
• Name a realistic defect that violates that invariant and causes the test to fail.
• Derive the expected result independently of test-double configuration.
• Select the test level capable of observing that defect.
• Treat missing contract or integration infrastructure as a coverage gap. Test doubles cannot substitute for that infrastructure.