Fork TS Checker Webpack Plugin

Webpack plugin that runs typescript type checker (with optional linter) on separate processes.

Installation

This plugin requires minimum webpack 2, typescript 2.1 and optionally tslint 5.0

npm install --save fork-ts-checker-webpack-plugin

Basic webpack config (with ts-loader)

var ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin');

var webpackConfig = {
  context: __dirname, // to automatically find tsconfig.json
  entry: './src/index.ts',
  output: {
    path: 'dist',
    filename: 'index.js'
  },
  module: {
    rules: [
      {
        test: /\.tsx?$/,
        include: './src',
        loader: 'ts-loader',
        options: {
          // disable type checker - we will use it in fork plugin
          transpileOnly: true 
        }
      }
    ]
  },
  plugins: [
    new ForkTsCheckerWebpackPlugin({
      watch: './src' // optional but improves performance (less stat calls)
    })
  ]
};

Motivation

There is already similar solution - awesome-typescript-loader. You can add CheckerPlugin and delegate checker to the separate process. The problem with awesome-typescript-loader is that it's a lot slower than ts-loader on incremental build in our case (~20s vs ~3s). Secondly, we use tslint and we wanted to run this also on separate process. This is why we've created this plugin. The performance is great because of reusing Abstract Syntax Trees between compilations and sharing these trees with tslint. We can also scale checker with multi-process mode - it will split work between processes to utilize maximum cpu power.

Options

tsconfig string - Path to tsconfig.json file. If not set, plugin will use path.resolve(compiler.options.context, './tsconfig.json').

tslint string | false - Path to tslint.json file. If not set, plugin will use path.resolve(compiler.options.context, './tslint.json'). If false, disables tslint.

watch string | string[] - Directories or files to watch by service. Not necessary but improves performance (reduces number of fs.stat calls).

blockEmit boolean - If true, plugin will block emit until check will be done. It's good setting for ci/production build because webpack will return code != 0 if there are type/lint errors. Default: false.

ignoreDiagnostics number[] - List of typescript diagnostic codes to ignore.

ignoreLints string[] - List of tslint rule names to ignore.

colors boolean - If false, disables built-in colors in logger messages. Default: true.

logger object - Logger instance. It should be object that implements method: error, warn, info. Default: console.

silent boolean - If true, logger will not be used. Default: false.

workers number - You can split type checking to few workers to speed-up on increment build. Be careful - if you don't want to increase build time, you should keep 1 core for build and 1 core for system free (for example system with 4 cpu threads should use max 2 workers). Second thing - node doesn't share memory between workers so keep in mind that memory usage will increase linearly. If you want to use workers, please experiment with workers number. In some scenarios increasing this number can increase check time (and of course memory consumption). Default: ForkTsCheckerWebpackPlugin.ONE_CPU.

Pre-computed consts:

• ForkTsCheckerWebpackPlugin.ONE_CPU - always use one cpu (core)
• ForkTsCheckerWebpackPlugin.ONE_CPU_FREE - leave only one cpu for build (probably will increase build time)
• ForkTsCheckerWebpackPlugin.TWO_CPUS_FREE - leave two cpus free (one for build, one for system)

memoryLimit number - Memory limit for service process in MB. If service exits with allocation failed error, increase this number. Default: 2048.

Plugin Hooks

This plugin provides some custom webpack hooks (all are sync):

License

MIT