Build/Test Tools: Add missing tools/webpack/development.js

Adds the missing `tools/webpack/development.js` file that was inadvertently
omitted from [61487].

See #64393.

git-svn-id: https://develop.svn.wordpress.org/trunk@61488 602fd350-edb4-49c9-b593-d223f7449a82
(cherry picked from commit 1af331f)

Author: youknowriad

tools/webpack/development.js

@@ -0,0 +1,72 @@
+/**
+ * External dependencies
+ */
+const TerserPlugin = require( 'terser-webpack-plugin' );
+
+/**
+ * Internal dependencies
+ */
+const { baseDir } = require( './shared' );
+
+/**
+ * Webpack configuration for development scripts (React Refresh).
+ *
+ * These scripts enable hot module replacement for block development
+ * when using `@wordpress/scripts` with the `--hot` flag.
+ *
+ * @param {Object} env             Environment options.
+ * @param {string} env.buildTarget Build target directory.
+ * @param {boolean} env.watch      Whether to watch for changes.
+ * @return {Object} Webpack configuration object.
+ */
+module.exports = function( env = { buildTarget: 'src/', watch: false } ) {
+	const buildTarget = env.buildTarget || 'src/';
+
+	const entry = {
+		// React Refresh runtime - exposes ReactRefreshRuntime global.
+		[ buildTarget + 'wp-includes/js/dist/development/react-refresh-runtime.js' ]: {
+			import: 'react-refresh/runtime',
+			library: {
+				name: 'ReactRefreshRuntime',
+				type: 'window',
+			},
+		},
+		[ buildTarget + 'wp-includes/js/dist/development/react-refresh-runtime.min.js' ]: {
+			import: 'react-refresh/runtime',
+			library: {
+				name: 'ReactRefreshRuntime',
+				type: 'window',
+			},
+		},
+		// React Refresh entry - injects runtime into global hook before React loads.
+		[ buildTarget + 'wp-includes/js/dist/development/react-refresh-entry.js' ]:
+			'@pmmmwh/react-refresh-webpack-plugin/client/ReactRefreshEntry.js',
+		[ buildTarget + 'wp-includes/js/dist/development/react-refresh-entry.min.js' ]:
+			'@pmmmwh/react-refresh-webpack-plugin/client/ReactRefreshEntry.js',
+	};
+
+	return {
+		target: 'browserslist',
+		// Must use development mode to preserve process.env.NODE_ENV checks
+		// in the source files. These scripts are only used during development.
+		mode: 'development',
+		devtool: false,
+		cache: true,
+		entry,
+		output: {
+			path: baseDir,
+			filename: '[name]',
+		},
+		optimization: {
+			minimize: true,
+			moduleIds: 'deterministic',
+			minimizer: [
+				new TerserPlugin( {
+					include: /\.min\.js$/,
+					extractComments: false,
+				} ),
+			],
+		},
+		watch: env.watch,
+	};
+};