Merge pull request #16613 from rwjblue/fix-engines-regression

[BUGFIX release] Prevent errors in ember-engines + 3.1 + proxies.

packages/ember-runtime/lib/system/core_object.js

@@ -109,6 +109,7 @@ function makeCtor(base) {
                 property === 'didAddListener' ||
                 property === 'didRemoveListener' ||
                 property === 'isDescriptor' ||
+                property === '_onLookup' ||
                 property in target
               ) {
                 return Reflect.get(target, property, receiver);

packages/ember-runtime/tests/system/core_object_test.js

@@ -1,7 +1,7 @@
 import { getOwner, setOwner } from 'ember-owner';
 import { get } from 'ember-metal';
 import CoreObject from '../../lib/system/core_object';
-import { moduleFor, AbstractTestCase } from 'internal-test-helpers';
+import { moduleFor, AbstractTestCase, buildOwner } from 'internal-test-helpers';
 
 moduleFor(
   'Ember.CoreObject',
@@ -62,6 +62,24 @@ moduleFor(
       assert.equal(get(proxy, 'lolol'), true, 'should be able to get data from a proxy');
     }
 
+    ['@test should not trigger proxy assertion when retrieving a re-registered proxy (GH#16610)'](
+      assert
+    ) {
+      let owner = buildOwner();
+
+      let someProxyishThing = CoreObject.extend({
+        unknownProperty() {
+          return true;
+        },
+      }).create();
+
+      // emulates ember-engines's process of registering services provided
+      // by the host app down to the engine
+      owner.register('thing:one', someProxyishThing, { instantiate: false });
+
+      assert.equal(owner.lookup('thing:one'), someProxyishThing);
+    }
+
     ['@test should not trigger proxy assertion when probing for a "symbol"'](assert) {
       let proxy = CoreObject.extend({
         unknownProperty() {