function-for-exports.js

module.exports = (options)=>(
   {
    entry: "./app/entry", // string | object | array
    // Here the application starts executing
    // and webpack starts bundling

    output: {
      // options related to how webpack emits results

      path: path.resolve(__dirname, "dist"), // string
      // the target directory for all output files
      // must be an absolute path (use the Node.js path module)

      filename: "bundle.js", // string
      // the filename template for entry chunks

      publicPath: "/assets/", // string
      // the url to the output directory resolved relative to the HTML page

      library: "MyLibrary", // string,
      // the name of the exported library

      libraryTarget: "umd", // universal module definition
      // the type of the exported library

      /* Advanced output configuration (click to show) */
    },

    module: {
      // configuration regarding modules

      rules: [
        // rules for modules (configure loaders, parser options, etc.)

        {
          test: /\.jsx?$/,
          include: [
            path.resolve(__dirname, "app")
          ],
          exclude: [
            path.resolve(__dirname, "app/demo-files")
          ],
          // these are matching conditions, each accepting a regular expression or string
          // test and include have the same behavior, both must be matched
          // exclude must not be matched (takes preferrence over test and include)
          // Best practices:
          // - Use RegExp only in test and for filename matching
          // - Use arrays of absolute paths in include and exclude
          // - Try to avoid exclude and prefer include

          issuer: { test, include, exclude },
          // conditions for the issuer (the origin of the import)

          enforce: "pre",
          enforce: "post",
          // flags to apply these rules, even if they are overridden (advanced option)

          loader: "babel-loader",
          // the loader which should be applied, it'll be resolved relative to the context
          // -loader suffix is no longer optional in webpack2 for clarity reasons
          // see webpack 1 upgrade guide

          options: {
            presets: ["es2015"]
          },
          // options for the loader
        },

        {
          test: /\.html$/,

          use: [
            // apply multiple loaders and options
            "htmllint-loader",
            {
              loader: "html-loader",
              options: {
                /* ... */
              }
            }
          ]
        },

        { oneOf: [ /* rules */ ] },
        // only use one of these nested rules

        { rules: [ /* rules */ ] },
        // use all of these nested rules (combine with conditions to be useful)

        { resource: { and: [ /* conditions */ ] } },
        // matches only if all conditions are matched

        { resource: { or: [ /* conditions */ ] } },
        { resource: [ /* conditions */ ] },
        // matches if any condition is matched (default for arrays)

        { resource: { not: /* condition */ } }
        // matches if the condition is not matched
      ],

      /* Advanced module configuration (click to show) */
    },

    resolve: {
      // options for resolving module requests
      // (does not apply to resolving to loaders)

      modules: [
        "node_modules",
        path.resolve(__dirname, "app")
      ],
      // directories where to look for modules

      extensions: [".js", ".json", ".jsx", ".css"],
      // extensions that are used

      alias: {
        // a list of module name aliases

        "module": "new-module",
        // alias "module" -> "new-module" and "module/path/file" -> "new-module/path/file"

        "only-module$": "new-module",
        // alias "only-module" -> "new-module", but not "only-module/path/file" -> "new-module/path/file"

        "module": path.resolve(__dirname, "app/third/module.js"),
        // alias "module" -> "./app/third/module.js" and "module/file" results in error
        // modules aliases are imported relative to the current context
      },
      /* alternative alias syntax (click to show) */

      /* Advanced resolve configuration (click to show) */
    },

    performance: {
      hints: "warning", // enum
      maxAssetSize: 200000, // int (in bytes),
      maxEntrypointSize: 400000, // int (in bytes)
      assetFilter: function(assetFilename) {
        // Function predicate that provides asset filenames
        return assetFilename.endsWith('.css') || assetFilename.endsWith('.js');
      }
    },

    devtool: "source-map", // enum
    // enhance debugging by adding meta info for the browser devtools
    // source-map most detailed at the expense of build speed.

    context: __dirname, // string (absolute path!)
    // the home directory for webpack
    // the entry and module.rules.loader option
    //   is resolved relative to this directory

    target: "web", // enum
    // the environment in which the bundle should run
    // changes chunk loading behavior and available modules

    externals: ["react", /^@angular\//],
    // Don't follow/bundle these modules, but request them at runtime from the environment

    stats: "errors-only",
    // lets you precisely control what bundle information gets displayed

    devServer: {
      proxy: { // proxy URLs to backend development server
        '/api': 'http://localhost:3000'
      },
      contentBase: path.join(__dirname, 'public'), // boolean | string | array, static file location
      compress: true, // enable gzip compression
      historyApiFallback: true, // true for index.html upon 404, object for multiple paths
      hot: true, // hot module replacement. Depends on HotModuleReplacementPlugin
      https: false, // true for self-signed, object for cert authority
      noInfo: true, // only errors & warns on hot reload
      // ...
    },

    plugins: [
      // ...
    ],
    // list of additional plugins


    /* Advanced configuration (click to show) */
  }
)