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Disallow setup and teardown hooks (`no-hooks`)

Jest provides global functions for setup and teardown tasks, which are called before/after each test case and each test suite. The use of these hooks promotes shared state between tests.

Rule details

This rule reports for the following function calls:

beforeAll
beforeEach
afterAll
afterEach

Examples of incorrect code for this rule:

/* eslint jest/no-hooks: "error" */

function setupFoo(options) {
  /* ... */
}

function setupBar(options) {
  /* ... */
}

describe('foo', () => {
  let foo;

  beforeEach(() => {
    foo = setupFoo();
  });

  afterEach(() => {
    foo = null;
  });

  it('does something', () => {
    expect(foo.doesSomething()).toBe(true);
  });

  describe('with bar', () => {
    let bar;

    beforeEach(() => {
      bar = setupBar();
    });

    afterEach(() => {
      bar = null;
    });

    it('does something with bar', () => {
      expect(foo.doesSomething(bar)).toBe(true);
    });
  });
});

Examples of correct code for this rule:

/* eslint jest/no-hooks: "error" */

function setupFoo(options) {
  /* ... */
}

function setupBar(options) {
  /* ... */
}

describe('foo', () => {
  it('does something', () => {
    const foo = setupFoo();
    expect(foo.doesSomething()).toBe(true);
  });

  it('does something with bar', () => {
    const foo = setupFoo();
    const bar = setupBar();
    expect(foo.doesSomething(bar)).toBe(true);
  });
});

Options

{
  "jest/no-hooks": [
    "error",
    {
      "allow": ["afterEach", "afterAll"]
    }
  ]
}

`allow`

This array option controls which Jest hooks are checked by this rule. There are four possible values:

"beforeAll"
"beforeEach"
"afterAll"
"afterEach"

By default, none of these options are enabled (the equivalent of { "allow": [] }).

Examples of incorrect code for the { "allow": ["afterEach"] } option:

/* eslint jest/no-hooks: ["error", { "allow": ["afterEach"] }] */

function setupFoo(options) {
  /* ... */
}

let foo;

beforeEach(() => {
  foo = setupFoo();
});

afterEach(() => {
  jest.resetModules();
});

test('foo does this', () => {
  // ...
});

test('foo does that', () => {
  // ...
});

Examples of correct code for the { "allow": ["afterEach"] } option:

/* eslint jest/no-hooks: ["error", { "allow": ["afterEach"] }] */

function setupFoo(options) {
  /* ... */
}

afterEach(() => {
  jest.resetModules();
});

test('foo does this', () => {
  const foo = setupFoo();
  // ...
});

test('foo does that', () => {
  const foo = setupFoo();
  // ...
});

When Not To Use It

If you prefer using the setup and teardown hooks provided by Jest, you can safely disable this rule.

2.9 KiB Raw Permalink Blame History

Disallow setup and teardown hooks (no-hooks)