Mode - Webpack Js Org

Providing the mode configuration option tells webpack to use its built-in optimizations accordingly.

string = 'production': 'none' | 'development' | 'production'

Usage

Provide the mode option in the config:

export default {
  mode: "development",
};

or pass it as a CLI argument:

bash

webpack --mode=development

The following string values are supported:

Option	Description
`development`	Sets `process.env.NODE_ENV` on `DefinePlugin` to value `development`. Enables useful names for modules and chunks.
`production`	Sets `process.env.NODE_ENV` on `DefinePlugin` to value `production`. Enables deterministic mangled names for modules and chunks, `FlagDependencyUsagePlugin`, `FlagIncludedChunksPlugin`, `ModuleConcatenationPlugin`, `NoEmitOnErrorsPlugin` and `TerserPlugin`.
`none`	Opts out of any default optimization options

If not set, webpack sets production as the default value for mode.

T> If mode is not provided via configuration or CLI, CLI will use any valid NODE_ENV value for mode.

Mode: development

// webpack.development.config.js
export default {
  mode: "development",
};

Mode: production

// webpack.production.config.js
export default {
  mode: "production",
};

Mode: none

// webpack.custom.config.js
export default {
  mode: "none",
};

If you want to change the behavior according to the mode variable inside the webpack.config.js, you have to export a function instead of an object:

const config = {
  entry: "./app.js",
  // ...
};

export default (env, argv) => {
  if (argv.mode === "development") {
    config.devtool = "source-map";
  }

  if (argv.mode === "production") {
    // ...
  }

  return config;
};