speed-measure-webpack-plugin

Speed Measure Plugin

^{(for webpack)}

The first step to optimising your webpack build speed, is to know where to focus your attention.

This plugin measures your webpack build speed, giving an output like this:

Install

npm install --save-dev speed-measure-webpack-plugin

or

yarn add -D speed-measure-webpack-plugin

Migrating

SMP follows semver. If upgrading a major version, you can consult the migration guide.

Requirements

SMP requires at least Node v6.

Usage

Change your webpack config from

const webpackConfig = {
  plugins: [
    new MyPlugin(),
    new MyOtherPlugin()
  ]
}

to

const SpeedMeasurePlugin = require("speed-measure-webpack-plugin");

const smp = new SpeedMeasurePlugin();

const webpackConfig = smp.wrap({
  plugins: [
    new MyPlugin(),
    new MyOtherPlugin()
  ]
});

and you're done! SMP will now be printing timing output to the console by default.

Check out the examples folder for some more examples.

Options

Options are (optionally) passed in to the constructor

const smp = new SpeedMeasurePlugin(options);

options.disable

Type: Boolean
Default: false

If truthy, this plugin does nothing at all. It is recommended to set this with something similar to { disable: !process.env.MEASURE } to allow opt-in measurements with a MEASURE=true npm run build

options.outputFormat

Type: String|Function
Default: "human"

Determines in what format this plugin prints its measurements

• "json" - produces a JSON blob
• "human" - produces a human readable output
• "humanVerbose" - produces a more verbose version of the human readable output
• If a function, it will call the function with the JSON blob being the first parameter, and just the response of the function as the output

options.outputTarget

Type: String|Function
Default: console.log

• If a string, it specifies the path to a file to output to.
• If a function, it will call the function with the output as the first parameter

options.pluginNames

Type: Object
Default: {}

By default, SMP derives plugin names through plugin.constructor.name. For some plugins this doesn't work (or you may want to override this default). This option takes an object of pluginName: PluginConstructor, e.g.

const uglify = new UglifyJSPlugin();
const smp = new SpeedMeasurePlugin({
  pluginNames: {
    customUglifyName: uglify
  }
});

const webpackConfig = smp.wrap({
  plugins: [
    uglify
  ]
});

options.granularLoaderData (experimental)

Type: Boolean
Default: false

If truthy, this plugin will attempt to break down the loader timing data to give per-loader timing information.

Points of note that the following loaders will have inaccurate results in this mode:

• loaders using separate processes (e.g. thread-loader) - these make it difficult to get timing information on the subsequent loaders, as they're not attached to the main thread
• loaders emitting file output (e.g. file-loader) - the time taken in outputting the actual file is not included in the running time of the loader

These are restrictions from technical limitations - ideally we would find solutions to these problems before removing the (experimental) flag on this options

License

MIT