TypeScript loader for webpack

Getting Started

Tutorials and examples can be found here.

Installation

npm install ts-loader

You will also need to install TypeScript if you have not already.

npm install typescript

or if you want to install TypeScript globally

npm install typescript -g
npm link typescript

Upgrading

Take advantage of the Changelog and Upgrade Guide.

Running

Use webpack like normal, including webpack --watch and webpack-dev-server, or through another build system using the Node.js API.

Compatibility

The current version is compatible with TypeScript 1.6 and above, including the nightly build. You may experience issues using the nightly build due to its nature, but a full test suite runs against the latest nightly every day to catch incompatibilites early. Please report any issues you experience with the nightly so that they can be fixed promptly.

Configuration

1. Create or update webpack.config.js like so:

   module.exports = {
     entry: './app.ts',
     output: {
       filename: 'bundle.js'
     },
     resolve: {
       // Add `.ts` and `.tsx` as a resolvable extension.
       extensions: ['', '.webpack.js', '.web.js', '.ts', '.tsx', '.js']
     },
     module: {
       loaders: [
         // all files with a `.ts` or `.tsx` extension will be handled by `ts-loader`
         { test: /\.tsx?$/, loader: 'ts-loader' }
       ]
     }
   }

2. Add a tsconfig.json file.

   {
     "compilerOptions": {
       "target": "es5",
       "sourceMap": true
     },
     "exclude": [
       "node_modules"
     ]
   }

The tsconfig.json file controls TypeScript-related options so that your IDE, the tsc command, and this loader all share the same options. TypeScript files from all subdirectories will get included except the ones matching exclude.

Failing the build on TypeScript compilation error

When the build fails (i.e. at least one typescript compile error occured), ts-loader does not propagate the build failure to webpack. The upshot of this is you can fail to notice an erroring build. This is inconvenient; particularly in continuous integration scenarios. If you want to ensure that the build failure is propogated it is advised that you make use of the webpack-fail-plugin. This plugin that will make the process return status code 1 when it finishes with errors in single-run mode. Et voilà! Build failure.

For more background have a read of this issue.

Options

There are two types of options: TypeScript options (aka "compiler options") and loader options. TypeScript options should be set using a tsconfig.json file. Loader options can be set either using a query when specifying the loader or through the ts property in the webpack configuration.

module.exports = {
  ...
  module: {
    loaders: [
      // specify option using query
      { test: /\.tsx?$/, loader: 'ts-loader?compiler=ntypescript' }
    ]
  },
  // specify option using `ts` property
  ts: {
    compiler: 'ntypescript'
  }
}

transpileOnly (boolean) (default=false)

If you want to speed up compilation significantly you can set this flag. However, many of the benefits you get from static type checking between different dependencies in your application will be lost. You should also set the isolatedModules TypeScript option if you plan to ever make use of this.

silent (boolean) (default=false)

If true, no console.log messages will be emitted. Note that most error messages are emitted via webpack which is not affected by this flag.

ignoreDiagnostics (number[]) (default=[])

You can squelch certain TypeScript errors by specifying an array of diagnostic codes to ignore.

compiler (string) (default='typescript')

Allows use of TypeScript compilers other than the official one. Should be set to the NPM name of the compiler, eg ntypescript.

configFileName (string) (default='tsconfig.json')

Allows you to specify a custom configuration file.

compilerOptions (object) (default={})

Allows overriding TypeScript options. Should be specified in the same format as you would do for the compilerOptions property in tsconfig.json.

instance (string)

Advanced option to force files to go through different instances of the TypeScript compiler. Can be used to force segregation between different parts of your code.

Loading other resources and code splitting

Loading css and other resources is possible but you will need to make sure that you have defined the require function in a declaration file.

declare var require: {
    <T>(path: string): T;
    (paths: string[], callback: (...modules: any[]) => void): void;
    ensure: (paths: string[], callback: (require: <T>(path: string) => T) => void) => void;
};

Then you can simply require assets or chunks per the webpack documentation.

require('!style!css!./style.css');

The same basic process is required for code splitting. In this case, you import modules you need but you don't directly use them. Instead you require them at split points. See this example for more details.

Contributing

Please see the contributer's guide.

License

MIT License