Build: Add building/watching support to Gutenberg packages

.gitignore

@@ -1,5 +1,6 @@
 # Directories/files that may be generated by this project
 build
+build-module
 coverage
 /hooks
 node_modules

bin/packages/build.js

@@ -0,0 +1,142 @@
+/**
+ * script to build WordPress packages into `build/` directory.
+ *
+ * Example:
+ *  node ./scripts/build.js
+ */
+
+/**
+ * External Dependenceis
+ */
+const fs = require( 'fs' );
+const path = require( 'path' );
+const glob = require( 'glob' );
+const babel = require( 'babel-core' );
+const chalk = require( 'chalk' );
+const mkdirp = require( 'mkdirp' );
+
+/**
+ * Internal dependencies
+ */
+const getPackages = require( './get-packages' );
+
+/**
+ * Module Constants
+ */
+const PACKAGES_DIR = path.resolve( __dirname, '../../packages' );
+const SRC_DIR = 'src';
+const BUILD_DIR = {
+	main: 'build',
+	module: 'build-module',
+};
+const DONE = chalk.reset.inverse.bold.green( ' DONE ' );
+
+/**
+ * Babel Configuration
+ */
+const babelDefaultConfig = require( '@wordpress/babel-preset-default' );
+babelDefaultConfig.babelrc = false;
+const presetEnvConfig = babelDefaultConfig.presets[ 0 ][ 1 ];
+const babelConfigs = {
+	main: Object.assign(
+		{},
+		babelDefaultConfig,
+		{ presets: [
+			[ 'env', Object.assign(
+				{},
+				presetEnvConfig,
+				{ modules: 'commonjs' },
+			) ],
+		] }
+	),
+	module: babelDefaultConfig,
+};
+
+/**
+ * Get the package name for a specified file
+ *
+ * @param  {string} file File name
+ * @return {string}      Package name
+ */
+function getPackageName( file ) {
+	return path.relative( PACKAGES_DIR, file ).split( path.sep )[ 0 ];
+}
+
+/**
+ * Get Build Path for a specified file
+ *
+ * @param  {string} file        File to build
+ * @param  {string} buildFolder Output folder
+ * @return {string}             Build path
+ */
+function getBuildPath( file, buildFolder ) {
+	const pkgName = getPackageName( file );
+	const pkgSrcPath = path.resolve( PACKAGES_DIR, pkgName, SRC_DIR );
+	const pkgBuildPath = path.resolve( PACKAGES_DIR, pkgName, buildFolder );
+	const relativeToSrcPath = path.relative( pkgSrcPath, file );
+	return path.resolve( pkgBuildPath, relativeToSrcPath );
+}
+
+/**
+ * Build a file for the required environments (node and ES5)
+ *
+ * @param {string} file    File path to build
+ * @param {boolean} silent Show logs
+ */
+function buildFile( file, silent ) {
+	buildFileFor( file, silent, 'main' );
+	buildFileFor( file, silent, 'module' );
+}
+
+/**
+ * Build a file for a specific environment
+ *
+ * @param {string}  file        File path to build
+ * @param {boolean} silent      Show logs
+ * @param {string}  environment Dist environment (node or es5)
+ */
+function buildFileFor( file, silent, environment ) {
+	const buildDir = BUILD_DIR[ environment ];
+	const destPath = getBuildPath( file, buildDir );
+	const babelOptions = babelConfigs[ environment ];
+
+	mkdirp.sync( path.dirname( destPath ) );
+	const transformed = babel.transformFileSync( file, babelOptions ).code;
+	fs.writeFileSync( destPath, transformed );
+	if ( ! silent ) {
+		process.stdout.write(
+			chalk.green( '  \u2022 ' ) +
+				path.relative( PACKAGES_DIR, file ) +
+				chalk.green( ' \u21D2 ' ) +
+				path.relative( PACKAGES_DIR, destPath ) +
+				'\n'
+		);
+	}
+}
+
+/**
+ * Build the provided package path
+ *
+ * @param {string} packagePath absolute package path
+ */
+function buildPackage( packagePath ) {
+	const srcDir = path.resolve( packagePath, SRC_DIR );
+	const files = glob.sync( srcDir + '/**/*.js', { nodir: true } )
+		.filter( ( file ) => ! /\.test\.js/.test( file ) );
+
+	process.stdout.write( `${ path.basename( packagePath ) }\n` );
+
+	files.forEach( ( file ) => buildFile( file, true ) );
+	process.stdout.write( `${ DONE }\n` );
+}
+
+const files = process.argv.slice( 2 );
+
+if ( files.length ) {
+	files.forEach( buildFile );
+} else {
+	process.stdout.write( chalk.inverse( '>> Building packages \n' ) );
+	getPackages()
+		.forEach( buildPackage );
+	process.stdout.write( '\n' );
+}

bin/packages/get-packages.js

@@ -0,0 +1,24 @@
+/**
+ * External Dependenceis
+ */
+const fs = require( 'fs' );
+const path = require( 'path' );
+
+/**
+ * Module Constants
+ */
+const PACKAGES_DIR = path.resolve( __dirname, '../../packages' );
+
+/**
+ * Returns the absolute path of all WordPress packages
+ *
+ * @return {Array} Package paths
+ */
+function getPackages() {
+	return fs
+		.readdirSync( PACKAGES_DIR )
+		.map( ( file ) => path.resolve( PACKAGES_DIR, file ) )
+		.filter( ( f ) => fs.lstatSync( path.resolve( f ) ).isDirectory() );
+}
+
+module.exports = getPackages;

bin/packages/watch.js

@@ -0,0 +1,66 @@
+/**
+ * External dependencies
+ */
+const fs = require( 'fs' );
+const { execSync } = require( 'child_process' );
+const path = require( 'path' );
+const chalk = require( 'chalk' );
+
+/**
+ * Internal dependencies
+ */
+const getPackages = require( './get-packages' );
+
+const BUILD_CMD = `node ${ path.resolve( __dirname, './build.js' ) }`;
+
+let filesToBuild = new Map();
+
+const exists = ( filename ) => {
+	try {
+		return fs.statSync( filename ).isFile();
+	} catch ( e ) {}
+	return false;
+};
+const rebuild = ( filename ) => filesToBuild.set( filename, true );
+
+getPackages().forEach( ( p ) => {
+	const srcDir = path.resolve( p, 'src' );
+	try {
+		fs.accessSync( srcDir, fs.F_OK );
+		fs.watch( path.resolve( p, 'src' ), { recursive: true }, ( event, filename ) => {
+			const filePath = path.resolve( srcDir, filename );
+
+			if ( ( event === 'change' || event === 'rename' ) && exists( filePath ) ) {
+				// eslint-disable-next-line no-console
+				console.log( chalk.green( '->' ), `${ event }: ${ filename }` );
+				rebuild( filePath );
+			} else {
+				const buildFile = path.resolve( srcDir, '..', 'build', filename );
+				try {
+					fs.unlinkSync( buildFile );
+					process.stdout.write(
+						chalk.red( '  \u2022 ' ) +
+              path.relative( path.resolve( srcDir, '..', '..' ), buildFile ) +
+              ' (deleted)' +
+              '\n'
+					);
+				} catch ( e ) {}
+			}
+		} );
+	} catch ( e ) {
+		// doesn't exist
+	}
+} );
+
+setInterval( () => {
+	const files = Array.from( filesToBuild.keys() );
+	if ( files.length ) {
+		filesToBuild = new Map();
+		try {
+			execSync( `${ BUILD_CMD } ${ files.join( ' ' ) }`, { stdio: [ 0, 1, 2 ] } );
+		} catch ( e ) {}
+	}
+}, 100 );
+
+// eslint-disable-next-line no-console
+console.log( chalk.red( '->' ), chalk.cyan( 'Watching for changes...' ) );

package.json

@@ -121,12 +121,14 @@
 	},
 	"scripts": {
 		"prebuild": "check-node-version --package",
-		"build": "cross-env NODE_ENV=production webpack",
+		"build:packages": "rimraf ./packages/*/build ./packages/*/build-module && node ./bin/packages/build.js",
+		"build": "npm run build:packages && cross-env NODE_ENV=production webpack",
 		"lint": "eslint .",
 		"lint:fix": "eslint . --fix",
 		"lint-php": "docker-compose run --rm composer run-script lint",
 		"predev": "check-node-version --package",
-		"dev": "cross-env webpack --watch",
+		"dev": "npm run build:packages && concurrently \"cross-env webpack --watch\" \"npm run dev:packages\"",
+		"dev:packages": "node ./bin/packages/watch.js",
 		"test": "npm run lint && npm run test-unit",
 		"test-php": "npm run lint-php && npm run test-unit-php",
 		"ci": "concurrently \"npm run lint && npm run build\" \"npm run test-unit:coverage-ci\"",

packages/date/package.json

@@ -16,7 +16,8 @@
 	"bugs": {
 		"url": "https://github.com/WordPress/gutenberg/issues"
 	},
-	"main": "src/index.js",
+	"main": "build/index.js",
+	"module": "build-module/index.js",
 	"dependencies": {
 		"moment": "2.22.1",
 		"moment-timezone": "0.5.16"