add acceptance test for duplicate methods (#276)

Author: jenweber

tests/acceptance/method-inheritance-test.js

@@ -0,0 +1,17 @@
+import moduleForAcceptance from 'ember-api-docs/tests/helpers/module-for-acceptance';
+import {test} from 'qunit';
+import { visit, click, findAll, findWithAssert } from 'ember-native-dom-helpers';
+import testSelector from 'ember-test-selectors';
+
+moduleForAcceptance('Acceptance | method inheritance')
+
+test('no duplicate methods displayed', async function (assert) {
+  await visit('/ember-data/2.14/classes/DS.JSONAPIAdapter');
+  assert.equal(findAll("[data-test-item='createRecord']").length, 1);
+});
+
+test('most local inherited method is shown', async function (assert) {
+  await visit('/ember-data/2.14/classes/DS.JSONAPIAdapter');
+  await click(`${testSelector('item', 'createRecord')} a`)
+  assert.ok(findWithAssert("[data-test-file='addon/adapters/rest.js']"));
+});