Use Application.create().buildInstance() when possible.

addon-test-support/application.js

@@ -0,0 +1,9 @@
+var __application__;
+
+export function setApplication(application) {
+  __application__ = application;
+}
+
+export function getApplication() {
+  return __application__;
+}

addon-test-support/build-owner.js

@@ -4,29 +4,37 @@ import global from './global';
 import ApplicationInstance from '@ember/application/instance';
 import Application from '@ember/application';
 import EmberObject from '@ember/object';
+import { Promise } from 'rsvp';
 
 import require from 'require';
 import Ember from 'ember';
-import { getResolver } from './resolver';
-
-const Owner = (function() {
-  // this module only supports Ember 2.4+ but is evaluated
-  // on older Ember versions (which we support via the legacy-0-6 API)
-  // and calling `.extend` with undefined is an issue
-  if (Ember._RegistryProxyMixin && Ember._ContainerProxyMixin) {
-    return EmberObject.extend(Ember._RegistryProxyMixin, Ember._ContainerProxyMixin);
-  }
 
-  return EmberObject.extend();
-})();
+let Owner;
 
 // different than the legacy-0-6-x version (build-registry.js)
 // in the following ways:
 //
+// * Accepts an application to _actually_ boot if possible
+// * falls back to "fake owner" if application is not present
 // * fewer fallbacks (supports only Ember 2.4+)
 // * returns "owner" (instead of a POJO with registry/container)
-// * directly calls getResolver if one was not provided
-export default function(resolver = getResolver()) {
+export default function({ application, resolver }) {
+  if (application) {
+    return application.boot().then(app => app.buildInstance().boot());
+  }
+
+  if (!resolver) {
+    throw new Error(
+      'You must set up the ember-test-helpers environment with either `setResolver` or `setApplication` before running any tests.'
+    );
+  }
+
+  if (Owner === undefined) {
+    Owner = EmberObject.extend(Ember._RegistryProxyMixin, Ember._ContainerProxyMixin, {
+      _emberTestHelpersMockOwner: true,
+    });
+  }
+
   let fallbackRegistry, registry, container;
   let namespace = EmberObject.create({
     Resolver: {
@@ -104,5 +112,5 @@ export default function(resolver = getResolver()) {
     }
   }
 
-  return owner;
+  return Promise.resolve().then(() => owner);
 }

addon-test-support/index.js

@@ -5,6 +5,7 @@ export { default as TestModuleForComponent } from './legacy-0-6-x/test-module-fo
 export { default as TestModuleForModel } from './legacy-0-6-x/test-module-for-model';
 
 export { setResolver } from './resolver';
+export { setApplication } from './application';
 export {
   default as setupContext,
   getContext,

addon-test-support/resolver.js

@@ -5,9 +5,5 @@ export function setResolver(resolver) {
 }
 
 export function getResolver() {
-  if (__resolver__ == null) {
-    throw new Error('you must set a resolver with `testResolver.set(resolver)`');
-  }
-
   return __resolver__;
 }

addon-test-support/setup-context.js

@@ -7,6 +7,8 @@ import Ember from 'ember';
 import { Promise } from 'rsvp';
 import { assert } from '@ember/debug';
 import global from './global';
+import { getResolver } from './resolver';
+import { getApplication } from './application';
 
 let __test_context__;
 
@@ -61,10 +63,30 @@ export default function(context, options = {}) {
 
   return new Promise(resolve => {
     // ensure "real" async and not "fake" RSVP based async
-    next(() => {
-      let resolver = options.resolver;
-      let owner = buildOwner(resolver);
-
+    next(resolve);
+  })
+    .then(() => {
+      let { resolver } = options;
+      let buildOwnerOptions;
+
+      // This handles precendence, specifying a specific option of
+      // resolver always trumps whatever is auto-detected, then we fallback to
+      // the suite-wide registrations
+      //
+      // At some later time this can be extended to support specifying a custom
+      // engine or application...
+      if (resolver) {
+        buildOwnerOptions = { resolver };
+      } else {
+        buildOwnerOptions = {
+          resolver: getResolver(),
+          application: getApplication(),
+        };
+      }
+
+      return buildOwner(buildOwnerOptions);
+    })
+    .then(owner => {
       context.owner = owner;
 
       context.set = function(key, value) {
@@ -110,7 +132,6 @@ export default function(context, options = {}) {
       _setupAJAXHooks();
       _setupPromiseListeners();
 
-      resolve(context);
+      return context;
     });
-  });
 }

addon-test-support/setup-rendering-context.js

@@ -53,8 +53,15 @@ export default function(context) {
     next(() => {
       let { owner } = context;
 
-      let dispatcher = owner.lookup('event_dispatcher:main') || Ember.EventDispatcher.create();
-      dispatcher.setup({}, '#ember-testing');
+      // When the host app uses `setApplication` (instead of `setResolver`) the event dispatcher has
+      // already been setup via `applicationInstance.boot()` in `./build-owner`. If using
+      // `setResolver` (instead of `setApplication`) a "mock owner" is created by extending
+      // `Ember._ContainerProxyMixin` and `Ember._RegistryProxyMixin` in this scenario we need to
+      // manually start the event dispatcher.
+      if (owner._emberTestHelpersMockOwner) {
+        let dispatcher = owner.lookup('event_dispatcher:main') || Ember.EventDispatcher.create();
+        dispatcher.setup({}, '#ember-testing');
+      }
 
       let OutletView = owner.factoryFor
         ? owner.factoryFor('view:-outlet')

tests/dummy/app/resolver.js

@@ -1,3 +1,12 @@
 import Resolver from 'ember-resolver';
 
-export default Resolver;
+export let registry = Object.create(null);
+export function setRegistry(newRegistry) {
+  registry = newRegistry;
+}
+
+export default Resolver.extend({
+  resolve(fullName) {
+    return registry[fullName] || this._super(...arguments);
+  },
+});

tests/helpers/resolver.js

@@ -1,30 +1,23 @@
 import Ember from 'ember';
-import { run } from '@ember/runloop';
 import { dasherize } from '@ember/string';
-import AppResolver from '../../resolver';
+import AppResolver, { setRegistry } from '../../resolver';
 import config from '../../config/environment';
-import { setResolver } from 'ember-test-helpers';
+import { setResolver, setApplication } from 'ember-test-helpers';
 import require from 'require';
+import App from '../../app';
 
-const Resolver = AppResolver.extend({
-  registry: {},
-
-  resolve(fullName) {
-    return this.registry[fullName] || this._super(...arguments);
-  },
-});
-
-const resolver = Resolver.create();
+const resolver = AppResolver.create();
 
 resolver.namespace = {
   modulePrefix: config.modulePrefix,
   podModulePrefix: config.podModulePrefix,
 };
 
 setResolver(resolver);
+setApplication(App.create({ autoboot: false }));
 
 export function setResolverRegistry(registry) {
-  run(resolver, 'set', 'registry', registry);
+  setRegistry(registry);
 }
 
 export default {