# webpack CLI The official CLI of webpack ## About webpack CLI provides a flexible set of commands for developers to increase speed when setting up a custom webpack project. As of webpack v4, webpack is not expecting a configuration file, but often developers want to create a more custom webpack configuration based on their use-cases and needs. webpack CLI addresses these needs by providing a set of tools to improve the setup of custom webpack configuration. ## How to install When you have followed the [Getting Started](https://webpack.js.org/guides/getting-started/) guide of webpack then webpack CLI is already installed! Otherwise ```bash npm install --save-dev webpack-cli ``` or ```bash yarn add webpack-cli --dev ``` ## Supported arguments and commands ### Usage All interactions with webpack-cli are of the form ```bash npx webpack-cli [command] [options] ``` If no command is specified then `bundle` command is used by default ### Help Usage To display basic commands and arguments - ```bash npx webpack-cli --help ``` To display all supported commands and arguments - ```bash npx webpack-cli --help=verbose ``` or ```bash npx webpack-cli --help verbose ``` ### Available Commands ``` build|bundle|b [entries...] [options] Run webpack (default command, can be omitted). configtest|t [config-path] Validate a webpack configuration. help|h [command] [option] Display help for commands and options. info|i [options] Outputs information about your system. init|create|new|c|n [generation-path] [options] Initialize a new webpack project. loader|l [output-path] [options] Scaffold a loader. migrate|m [new-config-path] Migrate a configuration to a new version. plugin|p [output-path] [options] Scaffold a plugin. serve|server|s [entries...] [options] Run the webpack dev server. version|v [commands...] Output the version number of 'webpack', 'webpack-cli' and 'webpack-dev-server' and commands. watch|w [entries...] [options] Run webpack and watch for files changes. ``` ### webpack 4 ``` Options: --analyze It invokes webpack-bundle-analyzer plugin to get bundle information -c, --config Provide path to a webpack configuration file e.g. ./webpack.config.js. --config-name Name of the configuration to use. -m, --merge Merge two or more configurations using 'webpack-merge'. --env Environment passed to the configuration when it is a function. --node-env Sets process.env.NODE_ENV to the specified value. --progress [value] Print compilation progress during build. -j, --json [value] Prints result as JSON or store it in a file. -d, --devtool Determine source maps to use. --no-devtool Do not generate source maps. --entry The entry point(s) of your application e.g. ./src/main.js. -h, --hot [value] Enables Hot Module Replacement --no-hot Disables Hot Module Replacement --mode Defines the mode to pass to webpack. --name Name of the configuration. Used when loading multiple configurations. -o, --output-path Output location of the file generated by webpack e.g. ./dist/. --prefetch Prefetch this request --stats [value] It instructs webpack on how to treat the stats e.g. verbose. --no-stats Disable stats output. -t, --target Sets the build target e.g. node. -w, --watch Watch for files changes. --no-watch Do not watch for file changes. --watch-options-stdin Stop watching when stdin stream has ended. --no-watch-options-stdin Do not stop watching when stdin stream has ended. Global options: --color Enable colors on console. --no-color Disable colors on console. -v, --version Output the version number of 'webpack', 'webpack-cli' and 'webpack-dev-server' and commands. -h, --help [verbose] Display help for commands and options. ``` ### webpack 5 Checkout [`OPTIONS.md`](https://github.com/webpack/webpack-cli/blob/master/OPTIONS.md) to see list of all available options. ## Exit codes and their meanings | Exit Code | Description | | --------- | -------------------------------------------------- | | `0` | Success | | `1` | Errors from webpack | | `2` | Configuration/options problem or an internal error | ## CLI Environment Variables | Environment Variable | Description | | ----------------------------------- | ------------------------------------------------------------------- | | `WEBPACK_CLI_SKIP_IMPORT_LOCAL` | when `true` it will skip using the local instance of `webpack-cli`. | | `WEBPACK_CLI_FORCE_LOAD_ESM_CONFIG` | when `true` it will force load the ESM config. | | `WEBPACK_PACKAGE` | Use a custom webpack version in CLI. | | `WEBPACK_CLI_HELP_WIDTH` | Use custom width for help output. | ## Configuration Environment Variables You can use the following environment variables inside your webpack configuration: | Environment Variable | Description | | -------------------- | -------------------------------------------- | | `WEBPACK_SERVE` | `true` if `serve\|s` is being used. | | `WEBPACK_BUILD` | `true` if `build\|bundle\|b` is being used. | | `WEBPACK_WATCH` | `true` if `--watch\|watch\|w` is being used. | Checkout [webpack.js.org](https://webpack.js.org/api/cli/) for more detailed documentation of `webpack-cli`.