Testing

Reference standards for test review. Only enforce rules that match the target project's conventions.

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Responsibility

• Tests asserting implementation (private methods, internal logic) instead of behavior, outputs, or user interactions. [Important]
• Tests asserting current implementation instead of functional requirements (AI bias). [Important]
• New whole functions (in diff) without corresponding tests. [Important]
• Tests that only verify rendering or mocks without covering actual business logic. [Important]
• Unit tests not isolating the function — mock outgoing/external calls (APIs, other modules, heavy dependencies). [Important]
• Multiple behaviors or edge cases in a single test case — one it or test per variation. [Suggestion]

Shadow mocks

• Mocking the core logic or the system under test (SUT) itself. [Important]

Snapshot tests

• Snapshot tests as the only validation for business behavior or complex conditional branches. [Important]
• Snapshots for logic (calculations, business conditions) instead of presentational components only. [Suggestion]

Test structure

• Test files not in __tests__/ directory next to the code they cover. [Suggestion]
• Test file naming not matching project convention (e.g. component.js → component.test.js). [Suggestion]
• Files containing logic without unit tests (not just DOM manipulation). [Important]

Test file order

• Imports order: SUT first, then dependencies. [Minor]
• Mocks not at top level (jest.mock('...') / vi.mock('...')). [Suggestion]
• No setup helper for SUT (setup() for functions, getInstance() for classes, render() for UI). [Suggestion]
• Missing beforeEach / afterEach for setup and cleanup. [Suggestion]
• More than one outer describe per module or inconsistent nesting per function/method. [Minor]

Conventions

• it / test not describing expected behavior. [Suggestion]
• Variants not using with ... or if ... in test name. [Minor]
• Negatives not tested with .not (mutation testing escape). [Suggestion]
• Test not following setup → execution → expectations order. [Suggestion]
• CSS/SVG imports not mocked via project file-mock. [Minor]
• HTML templates in tests inconsistent with project convention (JSX vs string). [Suggestion]

Critical verification checkpoints

• Does the test assert expected behavior from spec/requirements, or only what the code currently does?
• What am I mocking — is it an external boundary (API, I/O) or the logic I claim to be testing?
• Is the SUT isolated with mocks only on boundaries?
• Would a snapshot here hide logic that should have explicit assertions?