[BUGFIX release] ensure “pause on exception” pauses in the right place

packages/ember-metal/lib/error_handler.js

@@ -13,6 +13,12 @@ let getStack = error => {
   return stack;
 };
 
+export const onErrorTarget = {
+  get onerror() {
+    return dispatchOverride || getOnerror();
+  }
+};
+
 let onerror;
 // Ember.onerror getter
 export function getOnerror() {

packages/ember-metal/lib/run_loop.js

@@ -1,8 +1,7 @@
 import { GUID_KEY } from 'ember-utils';
 import { assert, isTesting } from 'ember-debug';
 import {
-  dispatchError,
-  setOnerror
+  onErrorTarget
 } from './error_handler';
 import {
   beginPropertyChanges,
@@ -18,25 +17,16 @@ function onEnd(current, next) {
   run.currentRunLoop = next;
 }
 
-const onErrorTarget = {
-  get onerror() {
-    return dispatchError;
-  },
-  set onerror(handler) {
-    return setOnerror(handler);
-  }
-};
-
 const backburner = new Backburner(['sync', 'actions', 'destroy'], {
-  GUID_KEY: GUID_KEY,
+  GUID_KEY,
   sync: {
     before: beginPropertyChanges,
     after: endPropertyChanges
   },
   defaultQueue: 'actions',
-  onBegin: onBegin,
-  onEnd: onEnd,
-  onErrorTarget: onErrorTarget,
+  onBegin,
+  onEnd,
+  onErrorTarget,
   onErrorMethod: 'onerror'
 });
 

packages/ember-metal/tests/error_handler_test.js

@@ -0,0 +1,56 @@
+import Ember from 'ember';
+import { run } from 'ember-metal';
+
+const ONERROR = Ember.onerror;
+const ADAPTER = Ember.Test.adapter;
+
+QUnit.module('error_handler', {
+  afterEach() {
+    Ember.onerror = ONERROR;
+    Ember.Test.adapter = ADAPTER;
+  }
+});
+
+function runThatThrows(message) {
+  return run(() => {
+    throw new Error(message);
+  });
+}
+
+test('by default there is no onerror', function(assert) {
+  Ember.onerror = undefined;
+  assert.throws(runThatThrows, Error);
+  assert.equal(Ember.onerror, undefined);
+});
+
+test('when Ember.onerror is registered', function(assert) {
+  assert.expect(1);
+  Ember.error = function() {
+    assert.ok(true, 'onerror called');
+  };
+  assert.throws(runThatThrows, Error);
+});
+
+test('when Ember.Test.adapter is registered', function(assert) {
+  assert.expect(1);
+
+  Ember.Test.adapter = function() {
+    assert.ok(true, 'adapter called');
+  };
+  assert.throws(runThatThrows, Error);
+});
+
+test('when both Ember.onerror Ember.Test.adapter is registered', function(assert) {
+  assert.expect(1);
+
+  Ember.Test.adapter = function() {
+    assert.ok(true, 'adapter called');
+  };
+
+  Ember.error = function() {
+    assert.ok(false, 'onerror was NEVER called');
+  };
+
+  assert.throws(runThatThrows, Error);
+});
+