complete transition to running loader as a module

Author: guybedford

karma.conf.js

@@ -48,6 +48,8 @@ module.exports = function(config) {
     [!options.ie8 ? 'test/*.spec.js' : 'test/*.normalize.spec.js'],
 
     {pattern: 'test/{loader,loads,syntax,worker}/**/*', included: false},
+    {pattern: 'node_modules/traceur/bin/traceur.js', included: false},
+    {pattern: 'node_modules/babel-core/browser.js', included: false},
     {pattern: 'node_modules/when/es6-shim/Promise.js', included: false},
     {pattern: 'dist/es6-module-loader*.js', included: false}
   ];
@@ -63,6 +65,9 @@ module.exports = function(config) {
       mocha: {
         reporter: 'html',
         timeout: 8000
+      },
+      system: {
+        transpiler: options.babel ? 'babel' : 'traceur'
       }
     }
   });

lib/index-babel.js

@@ -1,6 +1,7 @@
 var System = require('../dist/es6-module-loader.src');
 
 System.transpiler = 'babel';
+System.paths['babel'] = require.resolve('babel-core/browser.js');
 
 module.exports = {
   Loader: global.LoaderPolyfill,

lib/index-traceur.js

@@ -1,6 +1,7 @@
 var System = require('../dist/es6-module-loader.src');
 
 System.transpiler = 'traceur';
+System.paths['traceur'] = require.resolve('traceur/bin/traceur.js');
 
 module.exports = {
   Loader: global.LoaderPolyfill,

src/loader.js

@@ -230,88 +230,100 @@ function logloads(loads) {
     .then(function(source) {
       if (load.status != 'loading')
         return;
-      return loader.loaderObj.translate({ name: load.name, metadata: load.metadata, address: load.address, source: source });
-    })
 
-    // 15.2.4.5.2 CallInstantiate
-    .then(function(source) {
-      if (load.status != 'loading')
-        return;
-      load.source = source;
-      return loader.loaderObj.instantiate({ name: load.name, metadata: load.metadata, address: load.address, source: source });
-    })
+      return Promise.resolve(loader.loaderObj.translate({ name: load.name, metadata: load.metadata, address: load.address, source: source }))
 
-    // 15.2.4.5.3 InstantiateSucceeded
-    .then(function(instantiateResult) {
-      if (load.status != 'loading')
-        return;
-
-      if (instantiateResult === undefined) {
-        load.address = load.address || '<Anonymous Module ' + ++anonCnt + '>';
-
-        // instead of load.kind, use load.isDeclarative
-        load.isDeclarative = true;
-        __eval(loader.loaderObj.transpile(load), __global, load);
-      }
-      else if (typeof instantiateResult == 'object') {
-        load.depsList = instantiateResult.deps || [];
-        load.execute = instantiateResult.execute;
-        load.isDeclarative = false;
-      }
-      else
-        throw TypeError('Invalid instantiate return value');
+      // 15.2.4.5.2 CallInstantiate
+      .then(function(source) {
+        load.source = source;
+        return loader.loaderObj.instantiate({ name: load.name, metadata: load.metadata, address: load.address, source: source });
+      })
 
+      // 15.2.4.5.3 InstantiateSucceeded
+      .then(function(instantiateResult) {
+        if (instantiateResult === undefined) {
+          load.address = load.address || '<Anonymous Module ' + ++anonCnt + '>';
+
+          // instead of load.kind, use load.isDeclarative
+          load.isDeclarative = true;
+          return loader.loaderObj.transpile(load)
+          .then(function(transpiled) {
+            // Hijack System.register to set declare function
+            var curSystem = __global.System;
+            var curRegister = curSystem.register;
+            curSystem.register = function(name, deps, declare) {
+              if (typeof name != 'string') {
+                declare = deps;
+                deps = name;
+              }
+              // store the registered declaration as load.declare
+              // store the deps as load.deps
+              load.declare = declare;
+              load.depsList = deps;
+            }            
+            __eval(transpiled, __global, load);
+            curSystem.register = curRegister;
+          });
+        }
+        else if (typeof instantiateResult == 'object') {
+          load.depsList = instantiateResult.deps || [];
+          load.execute = instantiateResult.execute;
+          load.isDeclarative = false;
+        }
+        else
+          throw TypeError('Invalid instantiate return value');
+      })
       // 15.2.4.6 ProcessLoadDependencies
-      load.dependencies = [];
-      var depsList = load.depsList;
-
-      var loadPromises = [];
-      for (var i = 0, l = depsList.length; i < l; i++) (function(request, index) {
-        loadPromises.push(
-          requestLoad(loader, request, load.name, load.address)
-
-          // 15.2.4.6.1 AddDependencyLoad (load is parentLoad)
-          .then(function(depLoad) {
-
-            // adjusted from spec to maintain dependency order
-            // this is due to the System.register internal implementation needs
-            load.dependencies[index] = {
-              key: request,
-              value: depLoad.name
-            };
-
-            if (depLoad.status != 'linked') {
-              var linkSets = load.linkSets.concat([]);
-              for (var i = 0, l = linkSets.length; i < l; i++)
-                addLoadToLinkSet(linkSets[i], depLoad);
-            }
-
-            // console.log('AddDependencyLoad ' + depLoad.name + ' for ' + load.name);
-            // snapshot(loader);
-          })
-        );
-      })(depsList[i], i);
-
-      return Promise.all(loadPromises);
-    })
+      .then(function() {
+        load.dependencies = [];
+        var depsList = load.depsList;
+
+        var loadPromises = [];
+        for (var i = 0, l = depsList.length; i < l; i++) (function(request, index) {
+          loadPromises.push(
+            requestLoad(loader, request, load.name, load.address)
+
+            // 15.2.4.6.1 AddDependencyLoad (load is parentLoad)
+            .then(function(depLoad) {
+
+              // adjusted from spec to maintain dependency order
+              // this is due to the System.register internal implementation needs
+              load.dependencies[index] = {
+                key: request,
+                value: depLoad.name
+              };
+
+              if (depLoad.status != 'linked') {
+                var linkSets = load.linkSets.concat([]);
+                for (var i = 0, l = linkSets.length; i < l; i++)
+                  addLoadToLinkSet(linkSets[i], depLoad);
+              }
+
+              // console.log('AddDependencyLoad ' + depLoad.name + ' for ' + load.name);
+              // snapshot(loader);
+            })
+          );
+        })(depsList[i], i);
+
+        return Promise.all(loadPromises);
+      })
 
-    // 15.2.4.6.2 LoadSucceeded
-    .then(function() {
-      // console.log('LoadSucceeded ' + load.name);
-      // snapshot(loader);
+      // 15.2.4.6.2 LoadSucceeded
+      .then(function() {
+        // console.log('LoadSucceeded ' + load.name);
+        // snapshot(loader);
 
-      console.assert(load.status == 'loading', 'is loading');
+        console.assert(load.status == 'loading', 'is loading');
 
-      load.status = 'loaded';
+        load.status = 'loaded';
 
-      var linkSets = load.linkSets.concat([]);
-      for (var i = 0, l = linkSets.length; i < l; i++)
-        updateLinkSetOnLoad(linkSets[i], load);
+        var linkSets = load.linkSets.concat([]);
+        for (var i = 0, l = linkSets.length; i < l; i++)
+          updateLinkSetOnLoad(linkSets[i], load);
+      });
     })
-
     // 15.2.4.5.4 LoadFailed
     ['catch'](function(exc) {
-      console.assert(load.status == 'loading', 'is loading on fail');
       load.status = 'failed';
       load.exception = exc;
 

src/polyfill-wrapper-end.js

@@ -1,29 +1,15 @@
 
 // Define our eval outside of the scope of any other reference defined in this
 // file to avoid adding those references to the evaluation scope.
-function __eval(__source, __global, load) {
-  // Hijack System.register to set declare function
-  var __curRegister = System.register;
-  System.register = function(name, deps, declare) {
-    if (typeof name != 'string') {
-      declare = deps;
-      deps = name;
-    }
-    // store the registered declaration as load.declare
-    // store the deps as load.deps
-    load.declare = declare;
-    load.depsList = deps;
-  }
+function __eval(__source, __global, __load) {
   try {
-    eval('(function() { var __moduleName = "' + (load.name || '').replace('"', '\"') + '"; ' + __source + ' \n }).call(__global);');
+    eval('(function() { var __moduleName = "' + (__load.name || '').replace('"', '\"') + '"; ' + __source + ' \n }).call(__global);');
   }
   catch(e) {
     if (e.name == 'SyntaxError' || e.name == 'TypeError')
-      e.message = 'Evaluating ' + (load.name || load.address) + '\n\t' + e.message;
+      e.message = 'Evaluating ' + (__load.name || load.address) + '\n\t' + e.message;
     throw e;
   }
-
-  System.register = __curRegister;
 }
 
 })(typeof window != 'undefined' ? window : (typeof WorkerGlobalScope != 'undefined' ?

src/transpiler.js

@@ -2,49 +2,44 @@
  * Traceur and Babel transpile hook for Loader
  */
 (function(Loader) {
-  // Returns an array of ModuleSpecifiers
-  var transpiler, transpilerModule;
-
   // use Traceur by default
   Loader.prototype.transpiler = 'traceur';
 
   Loader.prototype.transpile = function(load) {
-    if (!transpiler) {
-      transpilerModule = this.get(this.transpiler);
-
-      if (transpilerModule) {
-        transpilerModule = transpilerModule['default'];
-      }
-      else {
-        transpilerModule = __global[this.transpiler];
-        if (!transpilerModule && typeof require != 'undefined') {
-          var curSystem = __global.System;
-          transpilerModule = require(this.transpiler == 'babel' ? 'babel-core' : 'traceur');
-          __global.System = curSystem;
-        }
-        if (!transpilerModule)
-          throw new TypeError('Include Traceur or Babel for module syntax support.');
-        this.set(this.transpiler, this.newModule({ 'default': transpilerModule, __useDefault: true }));
-      }
+    return this['import'](this.transpiler).then(function(transpiler) {
+      if (transpiler.__useDefault)
+        transpiler = transpiler['default'];
+      return 'var __moduleAddress = "' + load.address + '";' + (transpiler.Compiler ? traceurTranspile : babelTranspile).call(this, load, transpiler);
+    });
+  }
 
-      if (this.transpiler == 'babel')
-        transpiler = babelTranspile;
-      else if (this.transpiler == 'traceur')
-        transpiler = traceurTranspile;
-    }
+  var g = __global;
 
-    return 'var __moduleAddress = "' + load.address + '";' + transpiler.call(this, load);
+  Loader.prototype.instantiate = function(load) {
+    // load transpiler as a global (avoiding System clobbering)
+    if (load.name === this.transpiler)
+      return {
+        deps: [],
+        execute: function() {
+          var curSystem = g.System;
+          var curLoader = g.Reflect.Loader;
+          __eval('(function(require,exports,module){' + load.source + '})();', g, load);
+          g.System = curSystem;
+          g.Reflect.Loader = curLoader;
+          return System.newModule({ 'default': g[load.name], __useDefault: true });
+        }
+      };
   }
 
-  function traceurTranspile(load) {
+  function traceurTranspile(load, traceur) {
     var options = this.traceurOptions || {};
     options.modules = 'instantiate';
     options.script = false;
     options.sourceMaps = 'inline';
     options.filename = load.address;
     options.inputSourceMap = load.metadata.sourceMap;
 
-    var compiler = new transpilerModule.Compiler(options);
+    var compiler = new traceur.Compiler(options);
     var source = doTraceurCompile(load.source, compiler, options.filename);
 
     // add "!eval" to end of Traceur sourceURL
@@ -63,7 +58,7 @@
     }
   }
 
-  function babelTranspile(load) {
+  function babelTranspile(load, babel) {
     var options = this.babelOptions || {};
     options.modules = 'system';
     options.sourceMap = 'inline';
@@ -73,7 +68,7 @@
     options.blacklist = options.blacklist || [];
     options.blacklist.push('react');
 
-    var source = transpilerModule.transform(load.source, options).code;
+    var source = babel.transform(load.source, options).code;
 
     // add "!eval" to end of Babel sourceURL
     // I believe this does something?

test/_browser.js

@@ -1,3 +1,8 @@
 
 // Change base url to the karma "base"
 System.baseURL += 'base/';
+
+System.paths.traceur = 'node_modules/traceur/bin/traceur.js';
+System.paths.babel = 'node_modules/babel-core/browser.js';
+
+System.transpiler = __karma__.config.system.transpiler;

test/custom-loader.js

@@ -62,6 +62,18 @@
       return System.translate.apply(this, arguments);
     },
     instantiate: function (load) {
+      if (load.name == this.transpiler) {
+        var transpiler = this.transpiler;
+        return System.import(transpiler).then(function() {
+          return {
+            deps: [],
+            execute: function() {
+              return System.get(transpiler);
+            }
+          };
+        });
+      }
+
       if (load.name == 'error5') {
         return new Promise(function (resolve, reject) {
           setTimeout(function () { reject('error5'); }, 100);
@@ -111,9 +123,7 @@
     }
   });
 
-  customLoader.parse = function (load) {
-    return System.parse(load);
-  };
+  customLoader.transpiler = System.transpiler;
 
 
   if (typeof exports === 'object')

test/test-babel.html

@@ -6,7 +6,6 @@
   <script src="test.js"></script>
 
   <!-- set this to the path to babel.js -->
-  <script src="../node_modules/babel-core/browser.js"></script>
   <script src="../node_modules/regenerator/runtime.js"></script>
 
   <script>
@@ -19,6 +18,7 @@
   <script src="../dist/es6-module-loader.src.js"></script>
   <script>
     System.transpiler = 'babel';
+    System.paths['babel'] = '../node_modules/babel-core/browser.js';
   </script>
 
   <script>