Add babel/chokidar transpiler, see #1156

.gitignore

@@ -10,3 +10,4 @@ eslint/cache
 package-lock.json
 build
 dist
+transpile/cache/status.json

package.json

@@ -13,12 +13,14 @@
   "devDependencies": {
     "@babel/core": "^7.15.0",
     "@babel/preset-env": "^7.15.0",
+    "@babel/preset-typescript": "7.16.0",
     "@types/lodash": "^4.14.172",
     "@types/qunit": "^2.11.2",
     "@typescript-eslint/parser": "5.4.0",
     "archiver": "^5.3.0",
     "axios": "^0.21.4",
     "babel-eslint": "^10.1.0",
+    "chokidar": "^3.5.2",
     "docdash": "^1.2.0",
     "eslint": "^7.32.0",
     "eslint-plugin-react": "^7.25.1",

transpile/.eslintrc.js

@@ -0,0 +1,7 @@
+// Copyright 2018-2021, University of Colorado Boulder
+// @author Sam Reid (PhET Interactive Simulations)
+module.exports = {
+
+  // Use all of the default rules from eslint file for node code.
+  extends: '../eslint/chipper_eslintrc.js'
+};

transpile/transpile-all.js

@@ -0,0 +1,100 @@
+// Copyright 2021, University of Colorado Boulder
+
+/**
+ * Transpiles all *.ts and copies all *.js files to chipper/dist. Does not do type checking.
+ *
+ * Usage:
+ * cd chipper
+ * node transpile/transpile-all.js --watch
+ *
+ * OPTIONS:
+ * --watch                continue watching all directories and transpile on detected changes
+ * --ignoreInitial false  (default) transpile all files on startup
+ * --ignoreInitial true   skip initial transpile on startup
+ * --clean                dispose of the cache that tracks file status on startup, can be combined with other commands
+ *                        you would need to run --clean if the transpiled file status ever gets out of sync with the
+ *                        cache file status, for example if you deleted/modified a transpiled file
+ *
+ * @author Sam Reid (PhET Interactive Simulations)
+ */
+
+const start = Date.now();
+const chokidar = require( 'chokidar' );
+const transpileFunction = require( './transpileFunction' );
+const fs = require( 'fs' );
+const crypto = require( 'crypto' );
+const path = require( 'path' );
+
+const statusPath = '../chipper/transpile/cache/status.json';
+const args = process.argv.slice( 2 );
+
+// Track the status of each repo
+let status = {};
+
+// Make sure a directory exists for the cached status file
+fs.mkdirSync( path.dirname( statusPath ), { recursive: true } );
+
+// Clear the cache on `--clean`
+if ( args.includes( '--clean' ) ) {
+  fs.writeFileSync( statusPath, JSON.stringify( {}, null, 2 ) );
+}
+
+// Load cached status
+try {
+  status = JSON.parse( fs.readFileSync( statusPath, 'utf-8' ) );
+}
+catch( e ) {
+  status = {};
+  fs.writeFileSync( statusPath, JSON.stringify( status, null, 2 ) );
+}
+
+const index = args.indexOf( '--ignoreInitial' );
+let ignoreInitial = false;
+if ( index >= 0 ) {
+  if ( args[ index + 1 ] === 'true' ) {
+    ignoreInitial = true;
+  }
+  else if ( args[ index + 1 ] === 'false' ) {
+    ignoreInitial = false;
+  }
+  else {
+    throw new Error( 'illegal value for ignoreInitial' );
+  }
+}
+
+const activeRepos = fs.readFileSync( '../perennial/data/active-repos', 'utf-8' ).trim().split( '\n' );
+const paths = [];
+activeRepos.forEach( repo => {
+  paths.push( `../${repo}/js` );
+  paths.push( `../${repo}/images` );
+  paths.push( `../${repo}/sounds` );
+} );
+
+chokidar.watch( paths, {
+  ignoreInitial: ignoreInitial,
+  ignored: [ '**/chipper/dist/**/' ]
+} ).on( 'all', ( event, path ) => {
+  if ( path.endsWith( '.js' ) || path.endsWith( '.ts' ) ) {
+    const changeDetectedTime = Date.now();
+    const text = fs.readFileSync( path, 'utf-8' );
+    const hash = crypto.createHash( 'md5' ).update( text ).digest( 'hex' );
+
+    if ( !status[ path ] || status[ path ].md5 !== hash ) {
+      status[ path ] = { md5: hash };
+      transpileFunction( path, text );
+      fs.writeFileSync( statusPath, JSON.stringify( status, null, 2 ) );
+      const t = Date.now();
+      const elapsed = t - changeDetectedTime;
+      console.log( elapsed + 'ms: ' + path );
+    }
+  }
+} ).on( 'ready', () => {
+  if ( !args.includes( '--watch' ) ) {
+    console.log( 'Finished transpilation in ' + ( Date.now() - start ) + 'ms' );
+    process.exit( 0 );
+  }
+  else {
+    console.log( 'Finished initial scan in ' + ( Date.now() - start ) + 'ms' );
+    console.log( 'Watching...' );
+  }
+} );

transpile/transpileFunction.js

@@ -0,0 +1,19 @@
+// Copyright 2021, University of Colorado Boulder
+
+const core = require( '@babel/core' );
+const fs = require( 'fs' );
+const path = require( 'path' );
+
+const root = '../';
+
+module.exports = ( filename, text ) => {
+  const x = core.transformSync( text, {
+    filename: filename,
+    presets: [ '@babel/preset-typescript' ],
+    sourceMaps: 'inline'
+  } );
+  const relativePath = path.relative( root, filename );
+  const targetPath = path.join( root, 'chipper', 'dist', ...relativePath.split( path.sep ) ).split( '.ts' ).join( '.js' );
+  fs.mkdirSync( path.dirname( targetPath ), { recursive: true } );
+  fs.writeFileSync( targetPath, x.code );
+};