Type Check Plugin#

The Type Check plugin provides the ability to run TypeScript type checks in a separate process. The plugin internally integrates with fork-ts-checker-webpack-plugin.

Introduction#

The type checking logic of fork-ts-checker-webpack-plugin is similar to the native tsc command of TypeScript. It automatically reads the configuration options from tsconfig.json and can also be modified via the configuration options provided by the Type Check plugin.

The behavior of the plugin differs in the development and production builds:

• During development builds, type errors do not block the build process. They are only logged in the terminal.
• During production builds, type errors cause the build to fail in order to ensure the stability of the production code.

Quick Start#

Install Plugin#

You can install the plugin using the following command:

npm add @rsbuild/plugin-type-check -D

Register Plugin#

You can register the plugin in the rsbuild.config.ts file:

import { pluginTypeCheck } from '@rsbuild/plugin-type-check';

export default {
  plugins: [pluginTypeCheck()],
};

Configuring tsconfig.json#

The Type Check plugin by default performs checks based on the tsconfig.json file in the root directory of the current project. Below is an example of a tsconfig.json file, which you can also adjust according to the needs of your project.

{
  "compilerOptions": {
    "target": "ES2020",
    "lib": ["DOM", "ES2020"],
    "module": "ESNext",
    "strict": true,
    "skipLibCheck": true,
    "isolatedModules": true,
    "resolveJsonModule": true,
    "moduleResolution": "bundler"
  },
  "include": ["src"]
}

Please note that the fields in tsconfig.json will not affect the compilation behavior and output of Rsbuild, but will only affect the results of type checking.

Options#

enable#

Whether to enable TypeScript type checking.

• Type: boolean
• Default: true
• Example:

Disable TypeScript type checking:

pluginTypeCheck({
  enable: false,
});

Enable type checking only during production builds:

pluginTypeCheck({
  enable: process.env.NODE_ENV === 'production',
});

Enable type checking only during development builds (it is not recommended to disable type checking during production builds, as it may reduce the stability of the production code):

pluginTypeCheck({
  enable: process.env.NODE_ENV === 'development',
});

forkTsCheckerOptions#

To modify the options of fork-ts-checker-webpack-plugin, please refer to fork-ts-checker-webpack-plugin - README to learn about available options.

• Type: Object | Function
• Default:

const defaultOptions = {
  typescript: {
    // set 'readonly' to avoid emitting tsbuildinfo,
    // as the generated tsbuildinfo will break fork-ts-checker
    mode: 'readonly',
    // enable build when using project reference
    build: useReference,
    // avoid OOM issue
    memoryLimit: 8192,
    // use tsconfig of user project
    configFile: tsconfigPath,
    // use typescript of user project
    typescriptPath: require.resolve('typescript'),
  },
  issue: {
    // ignore types errors from node_modules
    exclude: [({ file = '' }) => /[\\/]node_modules[\\/]/.test(file)],
  },
  logger: {
    log() {
      // do nothing
      // we only want to display error messages
    },
    error(message: string) {
      console.error(message.replace(/ERROR/g, 'Type Error'));
    },
  },
};

Object Type#

When the value of forkTsCheckerOptions is an object, it will be deeply merged with the default configuration.

pluginTypeCheck({
  forkTsCheckerOptions: {
    issue: {
      exclude: [({ file = '' }) => /[\\/]some-folder[\\/]/.test(file)],
    },
  },
});

Function Type#

When the value of forkTsCheckerOptions is a function, the default configuration will be passed as the first argument. You can directly modify the configuration object or return an object as the final configuration.

pluginTypeCheck({
  forkTsCheckerOptions(options) {
    options.async = false;
    return options;
  },
});

Notes#

• If you have enabled ts-loader in your project and manually configured compileOnly: false, please disable the Type Check plugin to avoid duplicate type checking.
• Some errors will be displayed as warnings in IDEs such as VS Code, but they will still be displayed as errors in the fork-ts-checker-webpack-plugin check. For details, please refer to: Why are some errors reported as warnings?.

Performance Optimization#

Type checking has a significant performance overhead. You can refer to the Performance Guide in the official TypeScript documentation for performance optimization.

For example, properly configuring the include and exclude scopes in tsconfig.json can significantly reduce unnecessary type checking and improve TypeScript performance:

{
  "include": ["src"],
  "exclude": ["**/node_modules", "**/.*/"]
}

Vue Components#

fork-ts-checker-webpack-plugin does not support checking TypeScript code in .vue components. You can check for type issues in .vue files in the following ways:

1. Install the vue-tsc package, which provides the ability to check types in .vue files.

npm add vue-tsc -D

2. Add the vue-tsc --noEmit command to the build script in package.json:

{
  "scripts": {
-   "build": "rsbuild build"
+   "build": "vue-tsc --noEmit && rsbuild build"
  }
}

3. Since the production build uses vue-tsc for type checking, you can disable the Type Check plugin in the production build to avoid redundant checks.

pluginTypeCheck({
  enable: process.env.NODE_ENV === 'development',
});