浏览器单元测试（Typescript + Webpack）

Question

我想将单元测试添加到this 项目。这是一个基本的 webpack + typescript 项目，将被另一个 web 应用程序使用。单元测试应该在浏览器上运行。

我尝试了mocha，但只是import 'mocha' 引发编译错误。 （我在project_folder/test/test.ts 中有测试文件，这是 webpack 的入口。）

WARNING in ./node_modules/mocha/lib/mocha.js 219:20-37
Critical dependency: the request of a dependency is an expression
 @ ./node_modules/mocha/browser-entry.js
 @ ./test/test.ts

WARNING in ./node_modules/mocha/lib/mocha.js 227:24-70
Critical dependency: the request of a dependency is an expression
 @ ./node_modules/mocha/browser-entry.js
 @ ./test/test.ts

WARNING in ./node_modules/mocha/lib/mocha.js 277:24-35
Critical dependency: the request of a dependency is an expression
 @ ./node_modules/mocha/browser-entry.js
 @ ./test/test.ts

WARNING in ./node_modules/mocha/lib/mocha.js 327:35-48
Critical dependency: the request of a dependency is an expression
 @ ./node_modules/mocha/browser-entry.js
 @ ./test/test.ts

WARNING in ./node_modules/mocha/lib/mocha.js 342:23-44
Critical dependency: the request of a dependency is an expression
 @ ./node_modules/mocha/browser-entry.js
 @ ./test/test.ts

ERROR in ./node_modules/mocha/lib/browser/growl.js
Module not found: Error: Can't resolve '../../package' in 'C:\Users\s1n7ax\Documents\GitHub\open-unicode-converter\node_modules\mocha\lib\browser'
 @ ./node_modules/mocha/lib/browser/growl.js 127:13-37
 @ ./node_modules/mocha/lib/mocha.js
 @ ./node_modules/mocha/browser-entry.js
 @ ./test/test.ts

ERROR in ./node_modules/mkdirp/index.js
Module not found: Error: Can't resolve 'fs' in 'C:\Users\s1n7ax\Documents\GitHub\open-unicode-converter\node_modules\mkdirp'
 @ ./node_modules/mkdirp/index.js 2:9-22
 @ ./node_modules/mocha/lib/reporters/xunit.js
 @ ./node_modules/mocha/lib/reporters/index.js
 @ ./node_modules/mocha/lib/mocha.js
 @ ./node_modules/mocha/browser-entry.js
 @ ./test/test.ts
npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! open-unicode-converter@1.0.0 build: `webpack`
npm ERR! Exit status 2
npm ERR!
npm ERR! Failed at the open-unicode-converter@1.0.0 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\s1n7ax\AppData\Roaming\npm-cache\_logs\2019-03-02T20_59_10_221Z-debug.log

如果在没有 import 语句的情况下编写测试，则不会出现编译错误，但在运行时会抛出错误，因为方法 describe 未定义。

测试是一个打字稿文件很重要，因为必须导入打字稿类。是否有可以与 typescript + webpack 一起使用并在浏览器上运行的库？

测试/test.ts

import 'mocha'
describe('sample', () => {
    it('should return something', () => {
    })
});

webpack.config.js

const path = require('path');
const CopyWebpackPlugin = require('copy-webpack-plugin');
const webpack = require('webpack');


let distPath = path.resolve(__dirname, 'dist');
let srcPath = path.resolve(__dirname, 'src');
let testPath = path.resolve(__dirname, 'test');

module.exports = {
    mode: 'development',
    devtool: 'inline-source-map',
    entry: "./test/index.test.ts",
    module: {
        rules: [
            {
                test: /\.tsx?$/,
                use: 'ts-loader',
                exclude: /node_modules/
            }
        ]
    },
    plugins: [
        // this copy index.html from test/index.html to dist
        new CopyWebpackPlugin([
            {from: path.resolve(__dirname, 'test'), to: distPath, ignore: ['*.ts', '*.tsx', '*.js']}
        ]),
    ],
    resolve: {
        extensions: ['.tsx', '.ts', '.js']
    },
    output: {
        filename: '[name].js',
        path: distPath
    },
    devServer: {
        contentBase: path.join(__dirname, 'dist'),
        compress: true,
        port: 9000
    }
};

package.json

"scripts": {
    "build": "webpack",
    "watch": "webpack --watch",
    "test:browser": "npm run build && start http://localhost:9000 && webpack-dev-server"
}

Answer 1

找到了。

在webpack.config.js的顶部，添加

const nodeExternals = require('webpack-node-externals');

并添加到配置中：

externals: [nodeExternals()]

作为旁注，在package.json 我有一个。

"mocha": "6.2.1", 
"webpack": "4.41.0", 
"webpack-node-externals": "1.7.2",