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Rslint

    prefer-hooks-on-top

    Added in v0.6.3

    Configuration

    PresetConfigured Value
    ✅ jestPlugin.configs.all"error"
    rslint.config.ts
    import { defineConfig, jestPlugin } from '@rslint/core';

export default defineConfig([
  jestPlugin.configs.recommended,
  {
    rules: {
      'jest/prefer-hooks-on-top': 'error',
    },
  },
]);

    Rule Details

    Suggest placing Jest lifecycle hooks before any test cases in the same scope.

    Hooks (beforeAll, beforeEach, afterEach, afterAll) can appear anywhere in a describe callback, but Jest always runs them in a fixed order regardless of where they are written. Mixing hooks with test / it calls makes that execution order harder to follow, so this rule reports hooks registered after the first test case in the same scope.

    Examples of incorrect code for this rule:

    describe('foo', () => {
  beforeEach(() => {
    seedMyDatabase();
  });

  it('accepts this input', () => {
    // ...
  });

  beforeAll(() => {
    createMyDatabase();
  });

  it('returns that value', () => {
    // ...
  });

  describe('when the database has specific values', () => {
    const specificValue = '...';

    beforeEach(() => {
      seedMyDatabase(specificValue);
    });

    it('accepts that input', () => {
      // ...
    });

    it('throws an error', () => {
      // ...
    });

    afterEach(() => {
      clearLogger();
    });
    beforeEach(() => {
      mockLogger();
    });

    it('logs a message', () => {
      // ...
    });
  });

  afterAll(() => {
    removeMyDatabase();
  });
});

    Examples of correct code for this rule:

    describe('foo', () => {
  beforeAll(() => {
    createMyDatabase();
  });

  beforeEach(() => {
    seedMyDatabase();
  });

  afterAll(() => {
    clearMyDatabase();
  });

  it('accepts this input', () => {
    // ...
  });

  it('returns that value', () => {
    // ...
  });

  describe('when the database has specific values', () => {
    const specificValue = '...';

    beforeEach(() => {
      seedMyDatabase(specificValue);
    });

    beforeEach(() => {
      mockLogger();
    });

    afterEach(() => {
      clearLogger();
    });

    it('accepts that input', () => {
      // ...
    });

    it('throws an error', () => {
      // ...
    });

    it('logs a message', () => {
      // ...
    });
  });
});

    Differences from upstream

    Every function body is a scope of its own, where upstream only opens a new scope at a call expression. A hook written in a function that is never called registers nothing at run time, and a function passed to describe by name is that suite's body rather than a continuation of the code around it, so neither inherits the test cases registered outside it:

    describe('foo', () => {
  test('bar', () => {});

  // Not reported here; upstream reports it.
  function unused() {
    beforeEach(() => {});
  }
});

    The other side of that boundary is that a hook registered through a helper the suite does call is judged against the helper instead of the suite, and so goes unreported.

    Original Documentation