Jest

memo.md

Jest

Memory Leak

[Bug]: Memory consumption issues on Node JS 16.11.0+ #11956
jestjs/jest#11956

Mock

wip

order-of-execution.md

Jest

Setup / Teardown / Order of Execution

https://jestjs.io/ja/docs/setup-teardown

• 全ての describe 内の handler は、テストの実行前に実行される。
• beforeAll: 全てのテストの開始前に実行される。
• afterAll: 全てのテストの終了後に実行される。
• beforeEach: 各テストの開始前に実行される。
• afterEach: 各テストの終了後に実行される。

実行順序の例その1

console.log("===start===");

beforeAll(() => {
  console.log("beforeAll:1");
});

afterAll(() => {
  console.log("afterAll:1");
});

beforeEach(() => {
  console.log("beforeEach:1");
});

afterEach(() => {
  console.log("afterEach:1");
});

describe("describe", () => {
  console.log("describe:1");

  test("test:a", () => {
    console.log("test:a");
  });

  test("test:b", () => {
    console.log("test:b");
  });

  console.log("describe:2");
});

console.log("=== end ===");

===start===
describe:1
describe:2
=== end ===

beforeAll:1
  beforeEach:1
    test:a
  afterEach:1
  beforeEach:1
    test:b
  afterEach:1
afterAll:1

実行順序の例その2

console.log("===start===");

beforeAll(() => {
  console.log("beforeAll:global");
});
afterAll(() => {
  console.log("afterAll:global");
});
beforeEach(() => {
  console.log("beforeEach:global");
});
afterEach(() => {
  console.log("afterEach:global");
});

describe("describe:a", () => {
  console.log("describe:a1");

  beforeAll(() => {
    console.log("beforeAll:a");
  });
  afterAll(() => {
    console.log("afterAll:a");
  });
  beforeEach(() => {
    console.log("beforeEach:a");
  });
  afterEach(() => {
    console.log("afterEach:a");
  });

  console.log("describe:a2");

  test("test:a1", () => {
    console.log("test:a1");
  });
  test("test:a2", () => {
    console.log("test:a2");
  });

  describe("describe:b", () => {
    console.log("describe:b1");

    beforeAll(() => {
      console.log("beforeAll:b");
    });
    afterAll(() => {
      console.log("afterAll:b");
    });
    beforeEach(() => {
      console.log("beforeEach:b");
    });
    afterEach(() => {
      console.log("afterEach:b");
    });

    console.log("describe:b2");

    test("test:b1", () => {
      console.log("test:b1");
    });
    test("test:b2", () => {
      console.log("test:b2");
    });

    console.log("describe:b3");
  });

  console.log("describe:a3");
});

console.log("=== end ===");

===start===
describe:a1
describe:a2
describe:b1
describe:b2
describe:b3
describe:a3
=== end ===

beforeAll:global
  beforeAll:a

    beforeEach:global
      beforeEach:a
        test:a1
      afterEach:a
    afterEach:global

    beforeEach:global
      beforeEach:a
        test:a2
      afterEach:a
    afterEach:global

    beforeAll:b

      beforeEach:global
        beforeEach:a
          beforeEach:b
            test:b1
          afterEach:b
        afterEach:a
      afterEach:global

      beforeEach:global
        beforeEach:a
          beforeEach:b
            test:b2
          afterEach:b
        afterEach:a
      afterEach:global

    afterAll:b

  afterAll:a
afterAll:global