Webpack 没有因 TypeScript 错误而失败

Question

自从我升级到第 5 版后，webpack 不会因 TypeScript 错误而失败。

这是我的场景：

index.ts（入口点）：

const message: string = "Hello World";
console.log(message);

• 我跑./node_modules/.bin/webpack --config webpack.config.js --watch
• 一切都很好。这是 webpack 的输出：

[webpack-cli] Compilation starting...
[webpack-cli] Compilation finished
asset index.js 50 bytes [compared for emit] [minimized] (name: main)
./src/index.ts 65 bytes [built] [code generated]
webpack 5.0.0 compiled successfully in 1251 ms
[webpack-cli] watching files for updates...
[webpack-cli] Compilation starting...
[webpack-cli] Compilation finished
asset index.js 50 bytes [emitted] [minimized] (name: main)
./src/index.ts 65 bytes [built] [code generated]
webpack 5.0.0 compiled successfully in 152 ms
[webpack-cli] watching files for updates...

• 在下一步中，我添加了一个代码 sn-p，它会导致 TypeScript 错误：

const message: number = "Hello World"; // <= Type 'string' is not assignable to type 'number'.ts(2322)
console.log(message);

• 我预计 webpack 监视进程会失败或显示一些错误，但它不会失败。以下是 webpack 的输出：

[webpack-cli] Compilation starting...
[webpack-cli] Compilation finished
asset index.js 50 bytes [emitted] [minimized] (name: main)
./src/index.ts 65 bytes [built] [code generated]
webpack 5.0.0 compiled successfully in 244 ms
[webpack-cli] watching files for updates...

有趣的是，这只发生在我在启动 webpack 监视过程后更改 index.ts 时。如果我在没有 --watch 选项的情况下运行 webpack，我会得到这个输出，并且不会创建捆绑文件（如预期的那样）：

[webpack-cli] Compilation finished
assets by status 50 bytes [cached] 1 asset
./src/index.ts 65 bytes [built] [code generated] [1 error]

ERROR in /Users/oliverschwendener/projects/test/src/index.ts
./src/index.ts
[tsl] ERROR in /Users/oliverschwendener/projects/test/src/index.ts(1,7)
      TS2322: Type 'string' is not assignable to type 'number'.

webpack.config.js：

const path = require('path');

const config = {
    entry: './src/index.ts',
    module: {
        rules: [
            {
                test: /\.tsx?$/,
                use: 'ts-loader',
                exclude: /node_modules/,
            },
        ],
    },
    resolve: {
        extensions: [ '.tsx', '.ts', '.js' ],
    },
    output: {
        filename: 'index.js',
        path: path.resolve(__dirname, 'bundle'),
    },
};

module.exports = config;

*编辑：这是我的 tsconfig.json

{
  "compilerOptions": {
    "target": "es2015",
    "module": "commonjs",
    "lib": ["dom", "es2017"],
    "sourceMap": true,
    "strict": true,
    "noImplicitAny": true,
    "strictNullChecks": true,
    "noUnusedLocals": true,
    "moduleResolution": "node"
  }
}

我无法想象这是 webpack、webpack-cli 或 ts-loader 中的错误。所以我猜我的配置有问题。谁能告诉我这里有什么问题？谢谢！

• webpack 5.3.1（webpack 版本 4.44.2 一切正常）
• webpack-cli 4.1.0
• ts-loader 8.0.7
• 打字稿 4.0.5

Answer 1

在您的tsconfig.json 中，您可以将noEmitOnError 设置为true，以确保遇到错误时进程中断：

{
    "compilerOptions": {
        "noEmitOnError": true,

（没有显式设置，默认为false）

Answer 2

没关系，这是 ts-loader 中的一个错误：https://github.com/TypeStrong/ts-loader/issues/1204