Examples: Revive JSM -> JS Rollup script

package.json

@@ -62,6 +62,7 @@
     "start": "npm run dev",
     "test": "npm run test-lint && npm run test-unit",
     "build": "rollup -c utils/build/rollup.config.js",
+    "build-examples": "rollup -c utils/build/rollup-examples.config.js",
     "dev": "concurrently --names \"ROLLUP,HTTP\" -c \"bgBlue.bold,bgGreen.bold\" \"rollup -c utils/build/rollup.config.js -w -m inline\" \"servez -p 8080\"",
     "lint-fix": "eslint src --ext js --ext ts --fix && eslint examples/js examples/jsm --ext js --ext ts --ignore-pattern libs --fix",
     "lint-docs": "eslint docs --ext html",

utils/build/rollup-examples.config.js

@@ -0,0 +1,107 @@
+const path = require( 'path' );
+const fs = require( 'fs' );
+
+// Creates a rollup config object for the given file to
+// be converted to umd
+function createOutput( file, externalFiles ) {
+
+	const jsmRoot = path.resolve( process.cwd(), 'examples/jsm' );
+	const inputPath = path.resolve( jsmRoot, file );
+	const dirName = path.dirname( inputPath );
+	const outputPath = path.resolve( process.cwd(), 'examples/js', file );
+
+	if ( ! fs.existsSync( inputPath ) ) {
+
+		return null;
+
+	}
+
+	// Every import is marked as external so the output is 1-to-1. We
+	// assume that that global object should be the THREE object so we
+	// replicate the existing behavior.
+	return {
+
+		input: inputPath,
+		treeshake: false,
+		external: p => {
+
+			// Check if this imported file is being built separately and mark it as external if true
+			const otherPath = path.resolve( dirName, p ).substring( jsmRoot.length + 1 );
+			return externalFiles.includes( otherPath );
+
+		},
+
+		plugins: [ {
+
+			generateBundle: function ( options, bundle ) {
+
+				for ( var key in bundle ) {
+
+					bundle[ key ].code = bundle[ key ].code.replace( /three_module_js/g, 'THREE' );
+
+				}
+
+			}
+
+		} ],
+
+		output: {
+
+			format: 'umd',
+			name: 'THREE',
+			file: outputPath,
+
+			globals: () => 'THREE',
+			paths: p => {
+
+				return /three\.module\.js$/.test( p ) ? 'three' : path.relative( inputPath, p );
+
+			},
+			extend: true,
+
+			banner:
+				'/**\n' +
+				` * Generated from '${ path.relative( '.', inputPath ).replace( /\\/g, '/' ) }'\n` +
+				' */\n',
+			esModule: false
+
+		}
+
+	};
+
+}
+
+// Walk the file structure starting at the given directory and fire
+// the callback for every js file.
+function walk( dir, cb ) {
+
+	const files = fs.readdirSync( dir );
+	files.forEach( f => {
+
+		const p = path.join( dir, f );
+		const stats = fs.statSync( p );
+		if ( stats.isDirectory() ) {
+
+			walk( p, cb );
+
+		} else if ( f.endsWith( '.js' ) ) {
+
+			cb( p );
+
+		}
+
+	} );
+
+}
+
+// Gather up all the files
+const files = [];
+const jsRoot = path.resolve( process.cwd(), 'examples/js' );
+walk( jsRoot, p => {
+
+	files.push( p.substring( jsRoot.length + 1 ) );
+
+} );
+
+// Create a rollup config for each module.js file
+export default files.map( p => createOutput( p, files ) ).filter( p => ! ! p );