angular-testing-library：getByRole 查询仅适用于 hidden: true 选项

Question

我只是在尝试这个库，似乎无法通过他们的 ARIA 角色访问元素。

我使用 angular 10.0.6、jest 26.2.1 以及 jest-preset-angular 8.2.1 和 @testing-library/angular 10.0.1。我相信已经按照https://www.npmjs.com/package/jest-preset-angular和https://testing-library.com/docs/angular-testing-library/intro 中的描述设置了项目

这是我要测试的组件：

<h1>{{title}}</h1>
<img src="../assets/chuck-norris-logo.jpg" alt="Chuck Norris Approves!">
<p role="status">{{jokeText}}</p>
<button (click)="refreshJoke()">Refresh</button>

以及一些测试的相关部分：

test('refreshes joke on click', async () => {
    const component = await render(AppComponent);

    const button = component.getByRole('button');
    fireEvent.click(button);
  });

但是，我收到一条错误消息，指出找不到该角色。

TestingLibraryElementError: Unable to find an accessible element with the role "button"

There are no accessible roles. But there might be some inaccessible roles. If you wish to access them, then set the `hidden` option to `true`. Learn more about this here: https://testing-library.com/docs/dom-testing-library/api-queries#byrole

<div
  id="root1"
  ng-version="10.0.6"
>
  <h1>
    Chuck Norris
  </h1>
  <img
    alt="Chuck Norris Approves!"
    src="../assets/chuck-norris-logo.jpg"
  />
  <p
    role="status"
  >
    Chuck Norris uses canvas in IE.
  </p>
  <button>
    Refresh
  </button>
</div>

我可以通过将hidden选项设置为true.

TestingLibraryElementError: Unable to find an accessible element with the role "button"

There are no accessible roles. But there might be some inaccessible roles. If you wish to access them, then set the `hidden` option to `true`. Learn more about this here: https://testing-library.com/docs/dom-testing-library/api-queries#byrole

<div
  id="root1"
  ng-version="10.0.6"
>
  <h1>
    Chuck Norris
  </h1>
  <img
    alt="Chuck Norris Approves!"
    src="../assets/chuck-norris-logo.jpg"
  />
  <p
    role="status"
  >
    Chuck Norris uses canvas in IE.
  </p>
  <button>
    Refresh
  </button>
</div>

由于我尝试过的其他查询函数（例如getByText和getByTestId）工作正常并且我从未遇到过类似的反应问题，我想我以某种方式搞砸了我的配置。

这是我完整的 package.json

{
  "name": "chuck-norris-ng",
  "version": "0.0.0",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "jest",
    "test:watch": "jest --watch",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "~10.0.6",
    "@angular/common": "~10.0.6",
    "@angular/compiler": "~10.0.6",
    "@angular/core": "~10.0.6",
    "@angular/forms": "~10.0.6",
    "@angular/platform-browser": "~10.0.6",
    "@angular/platform-browser-dynamic": "~10.0.6",
    "@angular/router": "~10.0.6",
    "rxjs": "~6.6.0",
    "tslib": "^2.0.0",
    "zone.js": "~0.10.2"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~0.1000.4",
    "@angular/cli": "~10.0.4",
    "@angular/compiler-cli": "~10.0.6",
    "@testing-library/angular": "^10.0.1",
    "@testing-library/jest-dom": "^5.11.2",
    "@types/jest": "^26.0.7",
    "@types/node": "^12.11.1",
    "codelyzer": "^6.0.0",
    "jest": "^26.2.1",
    "jest-preset-angular": "^8.2.1",
    "protractor": "~7.0.0",
    "ts-node": "~8.3.0",
    "tslint": "~6.1.0",
    "typescript": "~3.9.7"
  },
  "jest": {
    "preset": "jest-preset-angular",
    "setupFilesAfterEnv": [
      "<rootDir>/src/setup-jest.ts"
    ]
  }
}

我已将我的 repo 上传到GitHub。我做错了什么？

Answer 1

我遇到了同样的问题，并通过删除https://www.npmjs.com/package/jest-preset-angular#usage的“用法”部分中引用的部分 jest 浏览器模拟解决了我的问题：

我从 jest-global-mocks.ts 文件中删除了以下内容：

Object.defineProperty(window, 'getComputedStyle', {
   value: () => {
      return {
         display: 'none',
         appearance: ['-webkit-appearance'],
      };
   },
});

我已经在https://www.amadousall.com/how-to-set-up-angular-unit-testing-with-jest/等文章中看到了类似的全局模拟<-- 这篇文章说“模拟一些属性和全局窗口对象的函数，以确保我们的测试可以在 JSDOM 环境中运行。” 但我不知道在使用 Angular-testing-library 时删除它是否是一个好主意（我也在使用https://www.npmjs.com/package/@testing-library/jest-dom） 。也许其他人可以帮助更详细地解释用例，但现在我很高兴可以再次使用 getByRole() 。