spawnUri: fixing test with recent support for multi-script tests.

lib/isolate/frog/isolateimpl.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /** Implementation of [Isolate2]. */
 class _Isolate2Impl implements Isolate2 {
   SendPort sendPort;
 
   _Isolate2Impl(this.sendPort);
 }
@@ skipping 318 matching lines @@
           'replyPort': _serializeMessage(replyPort)}));
     } else {
       _spawnWorker(factoryName, _serializeMessage(replyPort));
     }
   }
 
   /**
    * The src url for the script tag that loaded this code. Used to create
    * JavaScript workers.
    */
-  static String get _thisScript() =>
-      _thisScriptCache != null ? _thisScriptCache : _computeThisScript();
+  static String get _thisScript() {
+    if (_thisScriptCache == null) {
+      _thisScriptCache = _computeThisScript();
+    }
+    return _thisScriptCache;
+  }
 
   static String _thisScriptCache;
 
   // TODO(sigmund): fix - this code should be run synchronously when loading the
   // script. Running lazily on DOMContentLoaded will yield incorrect results.
   static String _computeThisScript() native @"""
     if (!$globalState.supportsWorkers || $globalState.isWorker) return null;
 
     // TODO(5334778): Find a cross-platform non-brittle way of getting the
     // currently running script.
     var scripts = document.getElementsByTagName('script');
     // The scripts variable only contains the scripts that have already been
     // executed. The last one is the currently running script.
     var script = scripts[scripts.length - 1];
     var src = script && script.src;
     if (!src) {
       // TODO()
       src = "FIXME:5407062" + "_" + Math.random().toString();
       if (script) script.src = src;
     }
-    _IsolateNatives._thisScriptCache = src;
     return src;
   """;
 
   /** Starts a new worker with the given URL. */
   static _Worker _newWorker(url) native "return new Worker(url);";
 
   /**
    * Spawns an isolate in a worker. [factoryName] is the Javascript constructor
    * name for the isolate entry point class.
    */
@@ skipping 227 matching lines @@
   }
 
   /**
    * Spawns an isolate in a worker. [factoryName] is the Javascript constructor
    * name for the isolate entry point class.
    */
   static void _spawnWorker2(functionName, uri, replyPort) {
     // TODO(eub): convert to 'main' once we switch back to port at top-level.
     if (functionName == null) functionName = 'isolateMain';
     if (uri == null) uri = _thisScript;
+    if (!(new Uri.fromString(uri).isAbsolute())) {
+      // The constructor of dom workers requires an absolute URL. If we use a
+      // relative path we will get a DOM exception.
+      String prefix = _thisScript.substring(0, _thisScript.lastIndexOf('/'));
+      uri = "$prefix/$uri";
+    }
     final worker = _newWorker(uri);
     worker.onmessage = (e) { _processWorkerMessage(worker, e); };
     var workerId = globalState.nextWorkerId++;
     // We also store the id on the worker itself so that we can unregister it.
     worker.id = workerId;
     globalState.workers[workerId] = worker;
     worker.postMessage(_serializeMessage({
       'command': 'start2',
       'id': workerId,
       // Note: we serialize replyPort twice because the child worker needs to
       // first deserialize the worker id, before it can correctly deserialize
       // the port (port deserialization is sensitive to what is the current
       // workerId).
       'replyTo': _serializeMessage(replyPort),
       'functionName': functionName }));
   }
 }