javascript - Jest 在第一次失败后停止测试套件

Question

我正在使用 Jest用于测试。

我想要的是在当前测试套件中的测试失败时停止执行该测试套件。

--bail option这不是我需要的，因为它会在一个测试套件失败后停止其他测试套件。

Answer 1

感谢this comment on github我能够使用自定义 testEnvironment 解决此问题。为此，jest-circus 需要通过 npm/yarn 安装。
值得注意的是 jest will set jest-circus to the default runner with jest v27 .

首先需要调整jest配置:

jest.config.js

module.exports = {
  rootDir: ".",
  testRunner: "jest-circus/runner",
  testEnvironment: "<rootDir>/NodeEnvironmentFailFast.js",
}

然后你需要实现一个自定义环境，上面的配置已经引用了它:

NodeEnvironmentFailFast.js

const NodeEnvironment = require("jest-environment-node")

class NodeEnvironmentFailFast extends NodeEnvironment {
  failedDescribeMap = {}
  registeredEventHandler = []

  async setup() {
    await super.setup()
    this.global.testEnvironment = this
  }

  registerTestEventHandler(registeredEventHandler) {
    this.registeredEventHandler.push(registeredEventHandler)
  }

  async executeTestEventHandlers(event, state) {
    for (let handler of this.registeredEventHandler) {
      await handler(event, state)
    }
  }

  async handleTestEvent(event, state) {
    await this.executeTestEventHandlers(event, state)

    switch (event.name) {
      case "hook_failure": {
        const describeBlockName = event.hook.parent.name

        this.failedDescribeMap[describeBlockName] = true
        // hook errors are not displayed if tests are skipped, so display them manually
        console.error(`ERROR: ${describeBlockName} > ${event.hook.type}\n\n`, event.error, "\n")
        break
      }
      case "test_fn_failure": {
        this.failedDescribeMap[event.test.parent.name] = true
        break
      }
      case "test_start": {
        if (this.failedDescribeMap[event.test.parent.name]) {
          event.test.mode = "skip"
        }
        break
      }
    }

    if (super.handleTestEvent) {
      super.handleTestEvent(event, state)
    }
  }
}

module.exports = NodeEnvironmentFailFast

---

注意

我添加了 registerTestEventHandler 功能，这不是快速失败功能所必需的，但我认为它非常有用，特别是如果您之前使用过 jasmine.getEnv() 并且它与 async/await 一起工作!
您可以像这样在测试的内部注册自定义处理程序(例如 beforeAll Hook ):

// testEnvironment is globally available (see above NodeEnvironmentFailFast.setup)
testEnvironment.registerTestEventHandler(async (event) => {
  if (event.name === "test_fn_failure") {
    await takeScreenshot()
  }
})

---

当一个test 失败时，同一describe 中的其他test 语句将被跳过。这也适用于嵌套的 describe block ，但 describe block 必须具有不同的名称。

执行以下测试:

describe("TestJest 3 ", () => {
  describe("TestJest 2 ", () => {
    describe("TestJest 1", () => {
      beforeAll(() => expect(1).toBe(2))
      test("1", () => {})
      test("1.1", () => {})
      test("1.2", () => {})
    })

    test("2", () => expect(1).toBe(2))
    test("2.1", () => {})
    test("2.2", () => {})
  })

  test("3", () => {})
  test("3.1", () => expect(1).toBe(2))
  test("3.2", () => {})
})

会产生如下日志:

 FAIL  suites/test-jest.spec.js
  TestJest 3 
    ✓ 3
    ✕ 3.1 (1 ms)
    ○ skipped 3.2
    TestJest 2 
      ✕ 2
      ○ skipped 2.1
      ○ skipped 2.2
      TestJest 1
        ○ skipped 1
        ○ skipped 1.1
        ○ skipped 1.2

  ● TestJest 3  › TestJest 2  › TestJest 1 › 1

    expect(received).toBe(expected) // Object.is equality

    Expected: 2
    Received: 1

      2 |   describe("TestJest 2 ", () => {
      3 |     describe("TestJest 1", () => {
    > 4 |       beforeAll(() => expect(1).toBe(2))
        |                                 ^
      5 |       test("1", () => {})
      6 |       test("1.1", () => {})
      7 |       test("1.2", () => {})

      at suites/test-jest.spec.js:4:33

  ● TestJest 3  › TestJest 2  › TestJest 1 › 1.1

    expect(received).toBe(expected) // Object.is equality

    Expected: 2
    Received: 1

      2 |   describe("TestJest 2 ", () => {
      3 |     describe("TestJest 1", () => {
    > 4 |       beforeAll(() => expect(1).toBe(2))
        |                                 ^
      5 |       test("1", () => {})
      6 |       test("1.1", () => {})
      7 |       test("1.2", () => {})

      at suites/test-jest.spec.js:4:33

  ● TestJest 3  › TestJest 2  › TestJest 1 › 1.2

    expect(received).toBe(expected) // Object.is equality

    Expected: 2
    Received: 1

      2 |   describe("TestJest 2 ", () => {
      3 |     describe("TestJest 1", () => {
    > 4 |       beforeAll(() => expect(1).toBe(2))
        |                                 ^
      5 |       test("1", () => {})
      6 |       test("1.1", () => {})
      7 |       test("1.2", () => {})

      at suites/test-jest.spec.js:4:33

  ● TestJest 3  › TestJest 2  › 2

    expect(received).toBe(expected) // Object.is equality

    Expected: 2
    Received: 1

       8 |     })
       9 | 
    > 10 |     test("2", () => expect(1).toBe(2))
         |                               ^
      11 |     test("2.1", () => {})
      12 |     test("2.2", () => {})
      13 |   })

      at Object.<anonymous> (suites/test-jest.spec.js:10:31)

  ● TestJest 3  › 3.1

    expect(received).toBe(expected) // Object.is equality

    Expected: 2
    Received: 1

      14 | 
      15 |   test("3", () => {})
    > 16 |   test("3.1", () => expect(1).toBe(2))
         |                               ^
      17 |   test("3.2", () => {})
      18 | })
      19 | 

      at Object.<anonymous> (suites/test-jest.spec.js:16:31)

Test Suites: 1 failed, 1 total
Tests:       2 failed, 6 skipped, 1 passed, 9 total
Snapshots:   0 total
Time:        0.638 s, estimated 1 s