cleanup _getPath

packages/ember-metal/lib/property_get.ts

@@ -11,12 +11,6 @@ import { isPath } from './path_cache';
 import { tagForProperty } from './tags';
 import { getCurrentTracker } from './tracked';
 
-const ALLOWABLE_TYPES = {
-  object: true,
-  function: true,
-  string: true,
-};
-
 export const PROXY_CONTENT = symbol('PROXY_CONTENT');
 
 export let getPossibleMandatoryProxyValue: (obj: object, keyName: string) => any;
@@ -178,24 +172,16 @@ export function _getPath<T extends object>(root: T, path: string): any {
   let parts = path.split('.');
 
   for (let i = 0; i < parts.length; i++) {
-    if (!isGettable(obj)) {
+    if (obj === undefined || obj === null || (obj as MaybeHasIsDestroyed).isDestroyed) {
       return undefined;
     }
 
     obj = get(obj, parts[i]);
-
-    if (obj && (obj as MaybeHasIsDestroyed).isDestroyed) {
-      return undefined;
-    }
   }
 
   return obj;
 }
 
-function isGettable(obj: any): boolean {
-  return obj !== undefined && obj !== null && ALLOWABLE_TYPES[typeof obj];
-}
-
 /**
   Retrieves the value of a property from an Object, or a default value in the
   case that the property returns `undefined`.

packages/ember-metal/tests/accessors/get_test.js

@@ -1,6 +1,8 @@
 import { ENV } from 'ember-environment';
+import { Object as EmberObject } from 'ember-runtime';
 import { get, getWithDefault, Mixin, observer, computed } from '../..';
 import { moduleFor, AbstractTestCase } from 'internal-test-helpers';
+import { run } from '@ember/runloop';
 
 function aget(x, y) {
   return x[y];
@@ -98,6 +100,23 @@ moduleFor(
       }
     }
 
+    ['@test get works with paths correctly'](assert) {
+      let func = function() {};
+      func.bar = 'awesome';
+
+      let destroyedObj = EmberObject.create({ bar: 'great' });
+      run(() => destroyedObj.destroy());
+
+      assert.equal(get({ foo: null }, 'foo.bar'), undefined);
+      assert.equal(get({ foo: { bar: 'hello' } }, 'foo.bar.length'), 5);
+      assert.equal(get({ foo: func }, 'foo.bar'), 'awesome');
+      assert.equal(get({ foo: func }, 'foo.bar.length'), 7);
+      assert.equal(get({}, 'foo.bar.length'), undefined);
+      assert.equal(get(function() {}, 'foo.bar.length'), undefined);
+      assert.equal(get('', 'foo.bar.length'), undefined);
+      assert.equal(get({ foo: destroyedObj }, 'foo.bar'), undefined);
+    }
+
     ['@test warn on attempts to call get with no arguments']() {
       expectAssertion(function() {
         get('aProperty');