instantiation checks alter

Author: guybedford

core/common.js

@@ -8,6 +8,8 @@ export var isWindows = typeof process !== 'undefined' && typeof process.platform
 var envGlobal = typeof self !== 'undefined' ? self : global;
 export { envGlobal as global }
 
+export var resolvedPromise = Promise.resolve();
+
 /*
  * Simple Symbol() shim
  */

core/loader-polyfill.js

@@ -1,4 +1,4 @@
-import { addToError, createSymbol } from './common.js';
+import { addToError, createSymbol, resolvedPromise } from './common.js';
 
 export { Loader, ModuleNamespace }
 
@@ -45,12 +45,24 @@ function Loader () {
 }
 // 3.3.1
 Loader.prototype.constructor = Loader;
+
+function ensureInstantiated (module) {
+  if (!(module instanceof ModuleNamespace))
+    throw new TypeError('Module instantiation did not return a valid namespace object.');
+  return module;
+}
+
 // 3.3.2
 Loader.prototype.import = function (key, parent) {
   if (typeof key !== 'string')
     throw new TypeError('Loader import method must be passed a module key string');
   // custom resolveInstantiate combined hook for better perf
-  return Promise.resolve(this[RESOLVE_INSTANTIATE](key, parent))
+  var loader = this;
+  return resolvedPromise
+  .then(function () {
+    return loader[RESOLVE_INSTANTIATE](key, parent);
+  })
+  .then(ensureInstantiated)
   //.then(Module.evaluate)
   .catch(function (err) {
     throw addToError(err, 'Loading ' + key + (parent ? ' from ' + parent : ''));
@@ -76,10 +88,7 @@ Loader.prototype[RESOLVE_INSTANTIATE] = function (key, parent) {
   var loader = this;
   return loader.resolve(key, parent)
   .then(function (resolved) {
-    var module = loader.registry.get(resolved);
-    if (!module)
-      throw new Error('Module ' + resolved + ' did not instantiate.');
-    return module;
+    return loader.registry.get(resolved);
   });
 };
 
@@ -91,7 +100,7 @@ function ensureResolution (resolvedKey) {
 
 Loader.prototype.resolve = function (key, parent) {
   var loader = this;
-  return Promise.resolve()
+  return resolvedPromise
   .then(function() {
     return loader[RESOLVE](key, parent);
   })

test/2-loader-api.js

@@ -1,15 +1,16 @@
 import assert from 'assert';
 import { Loader, ModuleNamespace } from '../core/loader-polyfill.js';
+import RegisterLoader from '../core/register-loader.js';
 import { pathToFileUrl } from '../core/common.js';
 
-describe('Loader Polyfill API', function() {
-  var loader = new Loader(pathToFileUrl(process.cwd()));
+describe('Loader Polyfill API', function () {
+  var loader = new Loader();
 
-  it('Should be an instance of itself', function() {
+  it('Should be an instance of itself', function () {
     assert(loader instanceof Loader);
   });
 
-  it('Should support the full registry API', function() {
+  it('Should support the full registry API', function () {
     assert(loader.registry);
 
     loader.registry.set('asdf', new ModuleNamespace({ asdf: 'asdf' }));
@@ -39,7 +40,7 @@ describe('Loader Polyfill API', function() {
     assert.equal(loader.registry.has('asdf'), false);
   });
 
-  it('Should support Module construction, evaluation and mutation', function() {
+  it('Should support Module construction, evaluation and mutation', function () {
     //var evaluated = false;
     var mutator = { a: 'asdf' };
     var module = new ModuleNamespace(mutator);/*, function() {
@@ -55,4 +56,31 @@ describe('Loader Polyfill API', function() {
 
     assert.equal(module.a, 'b');
   });
+
+  it('Should throw if instantiate hook doesnt instantiate', function () {
+    loader[loader.constructor.resolve] = function (x) {
+      return x;
+    };
+
+    return loader.import('x')
+    .catch(function (e) {
+      assert.equal(e.toString().indexOf('Error: Module instantiation did not return a valid namespace object.'), 0);
+    });
+  });
+});
+
+
+describe('Register Loader API', function () {
+  var loader = new RegisterLoader();
+
+  loader[RegisterLoader.resolve] = function (x) {
+    return x;
+  };
+
+  it('Should throw if instantiate doesnt instantiate', function () {
+    return loader.import('x')
+    .catch(function (e) {
+      assert.equal(e.toString().indexOf('Error: Module instantiation did not call an anonymous or correctly named System.register.'), 0);
+    });
+  });
 });