Updates from Sun Feb 15

- [react-packager][streamline oss] Injectable transformer | Amjad Masad

jestSupport/scriptPreprocess.js

@@ -1,6 +1,6 @@
 'use strict';
 
-var transformer = require('../packager/react-packager/src/JSTransformer/transformer.js');
+var transformer = require('../packager/transformer.js');
 
 function transformSource(src) {
   return transformer.transform(null, src).code;

packager/packager.js

@@ -84,10 +84,7 @@ function getAppMiddleware(options) {
     projectRoots: options.projectRoots,
     blacklistRE: blacklist(false),
     cacheVersion: '2',
-    polyfillModuleNames: [
-      path.resolve(__dirname, 'polyfill/console.js'),
-      path.resolve(__dirname, 'polyfill/error-guard.js'),
-    ]
+    transformModulePath: require.resolve('./transformer.js'),
   });
 }
 

packager/react-packager/src/JSTransformer/index.js

@@ -8,20 +8,21 @@ var Cache = require('./Cache');
 var _ = require('underscore');
 var workerFarm = require('worker-farm');
 
-var workers = workerFarm(require.resolve('./worker'));
-warmupWorkers();
-
 var readFile = q.nfbind(fs.readFile);
 
 module.exports = Transformer;
 Transformer.TransformError = TransformError;
 
 function Transformer(projectConfig) {
   this._cache = new Cache(projectConfig);
+  this._workers = workerFarm(
+    {autoStart: true},
+    projectConfig.transformModulePath
+  );
 }
 
 Transformer.prototype.kill = function() {
-  workerFarm.end(workers);
+  workerFarm.end(this._workers);
   return this._cache.end();
 };
 
@@ -36,6 +37,7 @@ Transformer.prototype.loadFileAndTransform = function(
   filePath,
   options
 ) {
+  var workers = this._workers;
   return this._cache.get(filePath, function() {
     return readFile(filePath)
       .then(function(buffer) {
@@ -62,19 +64,6 @@ Transformer.prototype.loadFileAndTransform = function(
   });
 };
 
-// worker-farm module starts workers lazily. But we want them to take time
-// to initialize so we send a dummy request.
-// see https://github.com/rvagg/node-worker-farm/issues/23
-function warmupWorkers() {
-  os.cpus().forEach(function() {
-    workers({
-      transformSets: ['es6'],
-      sourceCode: '\n',
-      options: {}
-    }, function() {});
-  });
-}
-
 function TransformError() {}
 TransformError.__proto__ = SyntaxError.prototype;
 

packager/react-packager/src/Server/index.js

@@ -18,6 +18,7 @@ function Server(options) {
     cacheVersion: options.cacheVersion,
     resetCache: options.resetCache,
     dev: options.dev,
+    transformModulePath: options.transformModulePath
   });
 
   this._fileWatcher = new FileWatcher(options.projectRoots);

packager/react-packager/src/JSTransformer/transformer.js → packager/transformer.js

@@ -30,4 +30,28 @@ function transform(transformSets, srcTxt, options) {
   return jstransform(visitorList, staticTypeSyntaxResult.code);
 }
 
-exports.transform = transform;
+module.exports = function(data, callback) {
+  var result;
+  try {
+    result = transform(
+      data.transformSets,
+      data.sourceCode,
+      data.options
+    );
+  } catch (e) {
+    return callback(null, {
+      error: {
+        lineNumber: e.lineNumber,
+        column: e.column,
+        message: e.message,
+        stack: e.stack,
+        description: e.description
+      }
+    });
+  }
+
+  callback(null, result);
+};
+
+// export for use in jest
+module.exports.transform = transform;