代码之家 › 专栏 › 技术社区 › Ekaterina M

如何使用Jest和测试库在JavaScript中进行单元测试?

testing-library jestjs unit-testing javascript

Ekaterina M · 技术社区 · 1 年前

我使用Jest和dom测试库,不使用REACT。

我还在我的项目中使用webpack。我一直在解决同样的问题:

expect(element).toBeInTheDocument()
element could not be found in the document

如何测试文档中是否有按钮?如果我使用没有脚本的静态HTML,我如何正确测试项目的模块?我应该手动添加脚本吗?我是第一次做,请帮帮我

我的测试文件:

import { getByRole } from '@testing-library/dom';
import '@testing-library/jest-dom';
import '@testing-library/jest-dom/extend-expect';

function getExampleDOM() {
  const div = document.createElement('div');
  div.innerHTML = `
      <div class="screen">
        <h1 class="game__title">GAME 2048</h1>
        <button type="button" class="btn btn-start">Start</button>
      </div>
      <div class="screen">
        <h2 class="game__title">Choose board size</h2>
        <ul class="size-list">
          <li>
            <button type="button" class="btn btn-size" data-size="3">3 x 3</button>
          </li>
          <li>
            <button type="button" class="btn btn-size" data-size="4">4 x 4 (classic)</button>
          </li>
          <li>
            <button type="button" class="btn btn-size" data-size="5">5 x 5</button>
          </li>
        </ul>
      </div>
      <div class="game__wrapper">
        <h2 class="game__score-title">Your score:<span class="game__score">0</span></h2>
        <div class="game-board"></div>
      </div>
  `;
  return div;
}

describe('startGame', () => {
  test('renders all necessary elements', () => {
    const container = getExampleDOM();
    const startBtn = getByRole(container, 'button', { name: /start/i });
    expect(startBtn).toBeInTheDocument();
  });
});

我的包.json:

{
  "name": "2048",
  "version": "1.0.0",
  "repository": {
    "url": "https://github.com/EkaterinaMuz/GAME2048.git"
  },
  "description": "",
  "scripts": {
    "test": "jest --w",
    "build": "webpack --mode development",
    "start": "webpack-dev-server --mode development --open",
    "predeploy": "npm run build",
    "deploy": "gh-pages -d dist"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@babel/eslint-parser": "^7.21.8",
    "@babel/polyfill": "^7.12.1",
    "@babel/preset-env": "^7.21.5",
    "@testing-library/user-event": "^14.4.3",
    "babel-loader": "^9.1.2",
    "clean-webpack-plugin": "^4.0.0",
    "css-loader": "^6.7.4",
    "eslint": "^8.2.0",
    "eslint-config-airbnb-base": "^15.0.0",
    "eslint-config-prettier": "^8.8.0",
    "eslint-plugin-import": "^2.27.5",
    "eslint-plugin-jest-dom": "^4.0.3",
    "eslint-plugin-prettier": "^4.2.1",
    "eslint-plugin-testing-library": "^5.11.0",
    "eslint-webpack-plugin": "^4.0.1",
    "file-loader": "^6.2.0",
    "gh-pages": "^5.0.0",
    "html-webpack-plugin": "^5.5.1",
    "jest": "^29.5.0",
    "jest-webpack": "^0.5.1",
    "style-loader": "^3.3.3",
    "webpack": "^5.83.1",
    "webpack-cli": "^5.1.1",
    "webpack-dev-server": "^4.15.0"
  },
  "dependencies": {
    "@testing-library/jest-dom": "^5.16.5",
    "hammerjs": "^2.0.8",
    "jest-environment-jsdom": "^29.5.0"
  }
}

我还添加了Jest配置

const config = {
  testEnvironment: 'jsdom',
  testEnvironmentOptions: {
    html: '<html lang="zh-cmn-Hant"></html>',
    url: 'https://jestjs.io/',
    userAgent: 'Agent/007',
  },
};

module.exports = config;

我在项目中也有webpack:

const path = require('path');
const HTMLWebpackPlugin = require('html-webpack-plugin');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');
// const ESLintPlugin = require('eslint-webpack-plugin');

module.exports = {
  mode: 'development',
  context: path.resolve(__dirname, 'src'),
  entry: ['@babel/polyfill', './scripts/index.js'],
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: 'bundle.js',
    assetModuleFilename: 'assets/[name][ext][query]',
  },
  devServer: {
    port: 3000,
  },
  plugins: [
    new HTMLWebpackPlugin({
      template: './index.html',
    }),
    new CleanWebpackPlugin(),
    // new ESLintPlugin({
    //   fix: true,
    // }),
  ],
  module: {
    rules: [
      {
        test: /\.css$/,
        use: ['style-loader', 'css-loader'],
      },
      // {
      //   test: /\.(png|jpg)$/,
      //   type: 'asset/resource',
      // },
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-env'],
          },
        },
      },
    ],
  },
};

////////////////////////////////////

0 回复 | 直到 1 年前