rule-testing

Testing & Quality

Rule mapping for testing

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I want to install this Agent Skill for this project in Codex.

Source SKILL.md: https://github.com/majiayu000/claude-skill-registry/blob/HEAD/skills/testing/rule-testing-carrot-foundation-methodology-rules/SKILL.md

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Rule testing

Apply this rule whenever work touches:

*.spec.ts
*.e2e.spec.ts

All test code in this repository runs under Jest with ts-jest. Tests must be deterministic, isolated, and free of real-world data.

Test file conventions

Pattern	Purpose
`{name}.spec.ts`	Unit tests, co-located with source
`{name}.e2e.spec.ts`	End-to-end / integration tests
`{name}.test-cases.ts`	Shared test data and fixtures

The test environment loads variables from .env-files/.env.test.

Data generation

Never hardcode test values that could be randomized. Use the following tools:

@faker-js/faker for primitive values (strings, numbers, dates, UUIDs).
zocker for generating objects that conform to a Zod schema.
Shared stubs from @carrot-fndn/shared/testing:
- stubRuleInput() - creates a valid RuleInput with sensible defaults.
- stubDocument() - creates a valid document fixture.
- createStubFromSchema() - generates a stub from any Zod schema.

No real data policy

Tests must never contain real-world identifiable information. Use obviously synthetic values:

Field	Fake example
Company name	`VERDE CAMPO LTDA`, `EXEMPLO INDUSTRIAS`
CNPJ	`11.222.333/0004-55`, `77.888.999/0001-22`
Vehicle plate	`FKE1A23`, `HIJ3K56`
Address	`Rua Modelo, 100`, `Av. Principal, 500`
Person name	`Pedro Santos`, `Ana Ferreira`

This applies to raw OCR text fixtures as well: both the input text and expected assertion values must use fake data consistently.

Table-driven tests

When a function must be tested against multiple scenarios, use it.each:

it.each([
  { input: 0, expected: 'zero' },
  { input: 1, expected: 'one' },
  { input: 2, expected: 'two' },
])('converts $input to "$expected"', ({ input, expected }) => {
  expect(numberToWord(input)).toBe(expected);
});

Partial assertions

Prefer expect.objectContaining when only a subset of fields matters for the assertion. This keeps tests resilient to unrelated field additions:

expect(result).toEqual(
  expect.objectContaining({
    status: 'APPROVED',
    score: expect.any(Number),
  }),
);