Skip to content

Latest commit

 

History

History
368 lines (281 loc) · 17.7 KB

cli.md

File metadata and controls

368 lines (281 loc) · 17.7 KB
Raw
title sort contributors related
Command Line Interface
2
evenstensberg
simon04
tbroadley
chenxsan
rencire
madhavarshney
EugeneHlushko
byzyk
wizardofhogwarts
EslamHiko
title url
Analysing and minimising the size of client side bundle with webpack and source-map-explorer

For proper usage and easy distribution of this configuration, webpack can be configured with webpack.config.js. Any parameters sent to the CLI will map to a corresponding parameter in the config file.

Read the installation guide if you don't already have webpack and CLI installed.

Usage with config file

webpack [--config webpack.config.js]

See configuration for the options in the configuration file.

Usage without config file

webpack <entry> [<entry>] -o <output>

<entry>

A filename or a set of named filenames which act as the entry point to build your project. You can pass multiple entries (every entry is loaded on startup). If you pass a pair in the form <name>=<request> you can create an additional entry point. It will be mapped to the configuration option entry.

<output>

A path and filename for the bundled file to be saved in. It will be mapped to the configuration options output.path and output.filename.

Example

If your project structure is as follows -

.
├── dist
├── index.html
└── src
    ├── index.js
    ├── index2.js
    └── others.js
webpack src/index.js -o dist/bundle.js

This will bundle your source code with entry as index.js and the output bundle file will have a path of dist and the filename will be bundle.js

	| Asset     | Size    | Chunks      | Chunk Names |
	|-----------|---------|-------------|-------------|
	| bundle.js | 1.54 kB | 0 [emitted] | index       |
	[0] ./src/index.js 51 bytes {0} [built]
	[1] ./src/others.js 29 bytes {0} [built]
webpack index=./src/index.js entry2=./src/index2.js dist/bundle.js

This will form the bundle with both the files as separate entry points.

	| Asset     | Size    | Chunks        | Chunk Names   |
	|-----------|---------|---------------|---------------|
	| bundle.js | 1.55 kB | 0,1 [emitted] | index, entry2 |
	[0] ./src/index.js 51 bytes {0} [built]
	[0] ./src/index2.js 54 bytes {1} [built]
	[1] ./src/others.js 29 bytes {0} {1} [built]

Common Options

W> Note that Command Line Interface has a higher precedence for the arguments you use it with than your configuration file. For instance, if you pass --mode="production" to webpack CLI and your configuration file uses development, production will be used.

List all of the options available on the cli

webpack --help
webpack -h

Build source using a config file

Specifies a different configuration file to pick up. Use this if you want to specify something different from webpack.config.js, which is the default.

webpack --config example.config.js

Print result of webpack as a JSON

webpack --json
webpack --json > stats.json

In every other case, webpack prints out a set of stats showing bundle, chunk and timing details. Using this option the output can be a JSON object. This response is accepted by webpack's analyse tool, or chrisbateman's webpack-visualizer, or th0r's webpack-bundle-analyzer. The analyse tool will take in the JSON and provide all the details of the build in graphical form.

Environment Options

When the webpack configuration exports a function, an "environment" may be passed to it.

webpack --env.production    # sets env.production == true
webpack --env.platform=web  # sets env.platform == "web"

The --env argument accepts various syntaxes:

Invocation Resulting environment
webpack --env prod "prod"
webpack --env.prod { prod: true }
webpack --env.prod=1 { prod: 1 }
webpack --env.prod=foo { prod: "foo" }
webpack --env.prod --env.min { prod: true, min: true }
webpack --env.prod --env min [{ prod: true }, "min"]
webpack --env.prod=foo --env.prod=bar {prod: [ "foo", "bar" ]}

T> See the environment variables guide for more information on its usage.

Config Options

Parameter Explanation Input type Default
--config Path to the config file string webpack.config.js or webpackfile.js
--config-register, -r Preload one or more modules before loading the webpack configuration array
--config-name Name of the config to use string
--env Environment passed to the config, when it is a function
--mode Mode to use, either "development" or "production" string

Output Options

This set of options allows you to manipulate certain output parameters of your build.

Parameter Explanation Input type Default
--output-chunk-filename The output filename for additional chunks string filename with [id] instead of [name] or [id] prefixed
--output-filename The output filename of the bundle string [name].js
--output-jsonp-function The name of the JSONP function used for chunk loading string webpackJsonp
--output-library Expose the exports of the entry point as library string
--output-library-target The type for exposing the exports of the entry point as library string var
--output-path The output path for compilation assets string Current directory
--output-pathinfo Include a comment with the request for every dependency boolean false
--output-public-path The public path for the assets string /
--output-source-map-filename The output filename for the SourceMap string [name].map or [outputFilename].map
--build-delimiter Display custom text after build output string Default string is null. You could provide a string such as === Build done ===

Example Usage

webpack index=./src/index.js index2=./src/index2.js --output-path='./dist' --output-filename='[name][hash].bundle.js'

| Asset                                | Size    | Chunks      | Chunk Names   |
|--------------------------------------|---------|-------------|---------------|
| index2740fdca26e9348bedbec.bundle.js |  2.6 kB | 0 [emitted] | index2        |
| index740fdca26e9348bedbec.bundle.js  | 2.59 kB | 1 [emitted] | index         |
	[0] ./src/others.js 29 bytes {0} {1} [built]
	[1] ./src/index.js 51 bytes {1} [built]
	[2] ./src/index2.js 54 bytes {0} [built]
webpack.js index=./src/index.js index2=./src/index2.js --output-path='./dist' --output-filename='[name][hash].bundle.js' --devtool source-map --output-source-map-filename='[name]123.map'

| Asset                                | Size    | Chunks      | Chunk Names   |
|--------------------------------------|---------|-------------|---------------|
| index2740fdca26e9348bedbec.bundle.js | 2.76 kB | 0 [emitted] | index2        |
|  index740fdca26e9348bedbec.bundle.js | 2.74 kB | 1 [emitted] | index         |
|                        index2123.map | 2.95 kB | 0 [emitted] | index2        |
|                         index123.map | 2.95 kB | 1 [emitted] | index         |
	[0] ./src/others.js 29 bytes {0} {1} [built]
	[1] ./src/index.js 51 bytes {1} [built]
	[2] ./src/index2.js 54 bytes {0} [built]

Debug Options

This set of options allows you to better debug the application containing assets compiled with webpack

Parameter Explanation Input type Default value
--debug Switch loaders to debug mode boolean false
--devtool Define source map type for the bundled resources string -
--progress Print compilation progress in percentage boolean false
--display-error-details Display details about errors boolean false

Module Options

These options allow you to bind modules as allowed by webpack

Parameter Explanation Usage
--module-bind Bind a file extension to a loader --module-bind js=babel-loader
--module-bind-post Bind a file extension to a post loader
--module-bind-pre Bind a file extension to a pre loader

Watch Options

These options make the build watch for changes in files of the dependency graph and perform the build again.

Parameter Explanation
--watch, -w Watch the filesystem for changes
--watch-aggregate-timeout Timeout for gathering changes while watching
--watch-poll The polling interval for watching (also enable polling)
--watch-stdin, --stdin Exit the process when stdin is closed

Optimize Options

These options allow you to manipulate optimisations for a production build using webpack

Parameter Explanation Plugin Used
--optimize-max-chunks Try to keep the chunk count below a limit LimitChunkCountPlugin
--optimize-min-chunk-size Try to keep the chunk size above a limit MinChunkSizePlugin
--optimize-minimize Minimize javascript and switches loaders to minimizing TerserPlugin & LoaderOptionsPlugin

Resolve Options

These allow you to configure the webpack resolver with aliases and extensions.

Parameter Explanation Example
--resolve-alias Setup a module alias for resolving --resolve-alias jquery-plugin=jquery.plugin
--resolve-extensions Setup extensions that should be used to resolve modules --resolve-extensions .es6 .js .ts
--resolve-loader-alias Minimize javascript and switches loaders to minimizing

Stats Options

These options allow webpack to display various stats and style them differently in the console output.

Parameter Explanation Type
--color, --colors Force colors on the console [default: enabled for TTY output only] boolean
--no-color, --no-colors Force no colors on the console boolean
--display Select display preset (verbose, detailed, normal, minimal, errors-only, none; since webpack 3.0.0) string
--display-cached Display also cached modules in the output boolean
--display-cached-assets Display also cached assets in the output boolean
--display-chunks Display chunks in the output boolean
--display-depth Display distance from entry point for each module boolean
--display-entrypoints Display entry points in the output boolean
--display-error-details Display details about errors boolean
--display-exclude Exclude modules in the output boolean
--display-max-modules Sets the maximum number of visible modules in output number
--display-modules Display even excluded modules in the output boolean
--display-optimization-bailout Scope hoisting fallback trigger (since webpack 3.0.0) boolean
--display-origins Display origins of chunks in the output boolean
--display-provided-exports Display information about exports provided from modules boolean
--display-reasons Display reasons about module inclusion in the output boolean
--display-used-exports Display information about used exports in modules (Tree Shaking) boolean
--hide-modules Hides info about modules boolean
--sort-assets-by Sorts the assets list by property in asset string
--sort-chunks-by Sorts the chunks list by property in chunk string
--sort-modules-by Sorts the modules list by property in module string
--verbose Show more details boolean

Advanced Options

Parameter Explanation Usage
--bail Abort the compilation on first error
--cache Enable in memory caching [Enabled by default for watch] --cache=false
--define Define any free variable, see shimming --define process.env.NODE_ENV="'development'"
--hot Enables Hot Module Replacement --hot=true
--labeled-modules Enables labeled modules [Uses LabeledModulesPlugin]
--live-reload Enables page live reloading --live-reload=true
--plugin Load this plugin
--prefetch Prefetch the particular file --prefetch=./files.js
--provide Provide these modules as globals, see shimming --provide jQuery=jquery
--records-input-path Path to the records file (reading)
--records-output-path Path to the records file (writing)
--records-path Path to the records file
--target The targeted execution environment --target='node'

Shortcuts

Shortcut Replaces
-d --debug --devtool cheap-module-eval-source-map --output-pathinfo
-p --optimize-minimize --define process.env.NODE_ENV="production", see building for production

Profiling

The --profile option captures timing information for each step of the compilation and includes this in the output.

webpack --profile

⋮
[0] ./src/index.js 90 bytes {0} [built]
    factory:22ms building:16ms = 38ms

For each module, the following details are included in the output as applicable:

  • factory: time to collect module metadata (e.g. resolving the filename)
  • building: time to build the module (e.g. loaders and parsing)
  • dependencies: time to identify and connect the module’s dependencies

Paired with --progress, --profile gives you an in-depth idea of which step in the compilation is taking how long. This can help you optimise your build in a more informed manner.

webpack --progress --profile

30ms building modules
1ms sealing
1ms optimizing
0ms basic module optimization
1ms module optimization
1ms advanced module optimization
0ms basic chunk optimization
0ms chunk optimization
1ms advanced chunk optimization
0ms module and chunk tree optimization
1ms module reviving
0ms module order optimization
1ms module id optimization
1ms chunk reviving
0ms chunk order optimization
1ms chunk id optimization
10ms hashing
0ms module assets processing
13ms chunk assets processing
1ms additional chunk assets processing
0ms recording
0ms additional asset processing
26ms chunk asset optimization
1ms asset optimization
6ms emitting
⋮