Allows SystemJS to load within Web Workers

This adds support for web workers building on the work done in ES6 Module Loader. Mostly just window checks, did have to do a plain old eval in this case. Fixes #165
systemjs · Aug 16, 2014 · 11d5144 · 11d5144
1 parent 176e752
commit 11d5144
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Showing 8 changed files with 98 additions and 16 deletions.
diff --git a/bower.json b/bower.json
@@ -3,7 +3,7 @@
   "version": "0.8.0",
   "main": "dist/system.js",
   "dependencies": {
-    "es6-module-loader": "~0.8.1"
+    "es6-module-loader": "~0.8.2"
   },
   "devDependencies": {
     "qunit": "~1.12.0"

diff --git a/dist/system.js b/dist/system.js
@@ -74,7 +74,8 @@ $__global.upgradeSystemLoader = function() {
     $__global.System = System.originalSystem;
   }
 
-  /*
+
+/*
  * Meta Extension
  *
  * Sets default metadata on a load record (load.metadata) from
@@ -788,9 +789,14 @@ function core(loader) {
 
   // override locate to allow baseURL to be document-relative
   var baseURI;
-  if (typeof window == 'undefined') {
+  if (typeof window == 'undefined' &&
+      typeof WorkerGlobalScope == 'undefined') {
     baseURI = process.cwd() + '/';
   }
+  // Inside of a Web Worker
+  else if(typeof window == 'undefined') {
+    baseURI = loader.global.location.href;
+  }
   else {
     baseURI = document.baseURI;
     if (!baseURI) {
@@ -1076,14 +1082,13 @@ function cjs(loader) {
   as well as a RequireJS-style require on System.require
 */
 function amd(loader) {
-
   // by default we only enforce AMD noConflict mode in Node
   var isNode = typeof module != 'undefined' && module.exports;
 
   // AMD Module Format Detection RegEx
   // define([.., .., ..], ...)
   // define(varName); || define(function(require, exports) {}); || define({})
-  var amdRegEx = /(?:^\s*|[}{\(\);,\n\?\&]\s*)define\s*\(\s*("[^"]+"\s*,\s*|'[^']+'\s*,\s*)?\s*(\[(\s*(("[^"]+"|'[^']+')\s*,|\/\/.*\r?\n|\/\*(.|\s)*?\*\/))*(\s*("[^"]+"|'[^']+')\s*,?\s*)?(\s*(\/\/.*\r?\n|\/\*(.|\s)*?\*\/)\s*)*\]|function\s*|{|[_$a-zA-Z\xA0-\uFFFF][_$a-zA-Z0-9\xA0-\uFFFF]*\))/;
+  var amdRegEx = /(?:^\s*|[}{\(\);,\n\?\&]\s*)define\s*\(\s*("[^"]+"\s*,\s*|'[^']+'\s*,\s*)?\s*(\[(\s*(("[^"]+"|'[^']+')\s*,|\/\/.*\r?\n|\/\*(.|\s)*?\*\/))*(\s*("[^"]+"|'[^']+')\s*,?)?(\s*(\/\/.*\r?\n|\/\*(.|\s)*?\*\/))*\s*\]|function\s*|{|[_$a-zA-Z\xA0-\uFFFF][_$a-zA-Z0-9\xA0-\uFFFF]*\))/;
   var commentRegEx = /(\/\*([\s\S]*?)\*\/|([^:]|^)\/\/(.*)$)/mg;
 
   var cjsRequirePre = "(?:^\\s*|[}{\\(\\);,\\n=:\\?\\&]\\s*)";
@@ -2041,7 +2046,11 @@ var $__curScript, __eval;
     }
   };
 
-  if (typeof window != 'undefined') {
+  var isWorker = typeof WorkerGlobalScope !== 'undefined' &&
+    self instanceof WorkerGlobalScope;
+  var isBrowser = typeof window != 'undefined';
+
+  if (isBrowser) {
     var head;
 
     var scripts = document.getElementsByTagName('script');
@@ -2078,6 +2087,29 @@ var $__curScript, __eval;
       $__global.upgradeSystemLoader();
     }
   }
+  else if(isWorker) {
+    doEval = function(source) {
+      try {
+        eval(source);
+      } catch(e) {
+        throw e;
+      }
+    };
+
+    if (!$__global.System || !$__global.LoaderPolyfill) {
+      var basePath = '';
+      try {
+        throw new Error('Getting the path');
+      } catch(err) {
+        var idx = err.stack.indexOf('at ') + 3;
+        var withSystem = err.stack.substr(idx, err.stack.substr(idx).indexOf('\n'));
+        basePath = withSystem.substr(0, withSystem.lastIndexOf('/') + 1);
+      }
+      importScripts(basePath + 'es6-module-loader.js');
+    } else {
+      $__global.upgradeSystemLoader();
+    }
+  }
   else {
     var es6ModuleLoader = require('es6-module-loader');
     $__global.System = es6ModuleLoader.System;
@@ -2093,6 +2125,4 @@ var $__curScript, __eval;
   }
 })();
 
-})(typeof window != 'undefined' ? window : global);
-
-
+})(this);
diff --git a/lib/extension-amd.js b/lib/extension-amd.js
@@ -4,7 +4,6 @@
   as well as a RequireJS-style require on System.require
 */
 function amd(loader) {
-
   // by default we only enforce AMD noConflict mode in Node
   var isNode = typeof module != 'undefined' && module.exports;
 

diff --git a/lib/extension-core.js b/lib/extension-core.js
@@ -63,9 +63,14 @@ function core(loader) {
 
   // override locate to allow baseURL to be document-relative
   var baseURI;
-  if (typeof window == 'undefined') {
+  if (typeof window == 'undefined' &&
+      typeof WorkerGlobalScope == 'undefined') {
     baseURI = process.cwd() + '/';
   }
+  // Inside of a Web Worker
+  else if(typeof window == 'undefined') {
+    baseURI = loader.global.location.href;
+  }
   else {
     baseURI = document.baseURI;
     if (!baseURI) {

diff --git a/lib/polyfill-wrapper-end.js b/lib/polyfill-wrapper-end.js
@@ -23,7 +23,11 @@ var $__curScript, __eval;
     }
   };
 
-  if (typeof window != 'undefined') {
+  var isWorker = typeof WorkerGlobalScope !== 'undefined' &&
+    self instanceof WorkerGlobalScope;
+  var isBrowser = typeof window != 'undefined';
+
+  if (isBrowser) {
     var head;
 
     var scripts = document.getElementsByTagName('script');
@@ -60,6 +64,29 @@ var $__curScript, __eval;
       $__global.upgradeSystemLoader();
     }
   }
+  else if(isWorker) {
+    doEval = function(source) {
+      try {
+        eval(source);
+      } catch(e) {
+        throw e;
+      }
+    };
+
+    if (!$__global.System || !$__global.LoaderPolyfill) {
+      var basePath = '';
+      try {
+        throw new Error('Getting the path');
+      } catch(err) {
+        var idx = err.stack.indexOf('at ') + 3;
+        var withSystem = err.stack.substr(idx, err.stack.substr(idx).indexOf('\n'));
+        basePath = withSystem.substr(0, withSystem.lastIndexOf('/') + 1);
+      }
+      importScripts(basePath + 'es6-module-loader.js');
+    } else {
+      $__global.upgradeSystemLoader();
+    }
+  }
   else {
     var es6ModuleLoader = require('es6-module-loader');
     $__global.System = es6ModuleLoader.System;
@@ -75,6 +102,4 @@ var $__curScript, __eval;
   }
 })();
 
-})(typeof window != 'undefined' ? window : global);
-
-
+})(this);
diff --git a/lib/polyfill-wrapper-start.js b/lib/polyfill-wrapper-start.js
@@ -67,4 +67,4 @@ $__global.upgradeSystemLoader = function() {
     $__global.System = System.originalSystem;
   }
 
-
+
diff --git a/test/test.js b/test/test.js
@@ -558,4 +558,13 @@ asyncTest('AMD -> System.register circular -> ES6', function() {
   }, err);
 });
 
+asyncTest('Using SystemJS in a Web Worker', function() {
+  var worker = new Worker('tests/worker.js');
+  worker.onmessage = function(e) {
+    ok(e.data.amd === 'AMD Module');
+    ok(e.data.es6 === 'ES6 Module');
+    start();
+  };
+});
+
 })();
diff --git a/test/tests/worker.js b/test/tests/worker.js
@@ -0,0 +1,14 @@
+importScripts('../../bower_components/traceur/traceur.js',
+              '../../bower_components/es6-module-loader/dist/es6-module-loader.js',
+              '../../dist/system.js');
+
+System.baseURL = '../';
+
+System.import('tests/es6-and-amd').then(function(m) {
+  postMessage({
+    amd: m.amd_module,
+    es6: m.es6_module
+  });
+}, function(err) {
+  console.error(err);
+});