[Bugfix]Fix autoscroll to methods issue

Author: akash-dsouza-3362

app/mixins/scroll-page.js

@@ -0,0 +1,23 @@
+import Mixin from '@ember/object/mixin';
+import { inject as service } from '@ember/service';
+import $ from 'jquery';
+import config from 'ember-api-docs/config/environment';
+
+export default Mixin.create({
+  scrollPositionReset: service(),
+  actions: {
+    didTransition() {
+      this._super();
+      if ((typeof FastBoot === 'undefined') && this.get('controller.anchor') === '' ) {
+        let elem = $('#methods');
+        let offset = (elem && elem.offset && elem.offset()) ? elem.offset().top : null;
+        if (offset) {
+          const navMenuHeight = $('header').outerHeight();
+          $(config.APP.scrollContainerSelector).scrollTop(offset - navMenuHeight - 10);
+        }
+      } else {
+        this.get('scrollPositionReset').doReset();
+      }
+    }
+  }
+});

app/routes/project-version/classes/class/methods.js

@@ -1,5 +1,6 @@
 import Route from '@ember/routing/route';
+import ScrollPage from 'ember-api-docs/mixins/scroll-page';
 
-export default Route.extend({
+export default Route.extend(ScrollPage, {
   templateName: 'methods'
 });

app/routes/project-version/modules/module/methods.js

@@ -1,5 +1,6 @@
 import Route from '@ember/routing/route';
+import ScrollPage from 'ember-api-docs/mixins/scroll-page';
 
-export default Route.extend({
+export default Route.extend(ScrollPage, {
   templateName: 'methods'
 });

app/routes/project-version/namespaces/namespace/methods.js

@@ -1,5 +1,6 @@
 import Route from '@ember/routing/route';
+import ScrollPage from 'ember-api-docs/mixins/scroll-page';
 
-export default Route.extend({
+export default Route.extend(ScrollPage, {
   templateName: 'methods'
 });

app/templates/project-version/classes/class.hbs

@@ -63,6 +63,7 @@
              (query-params anchor="")
              class="tabbed-layout__menu__item"
              activeClass="tabbed-layout__menu__item_selected"
+             id="methods"
              current-when=(concat parentName ".methods")
              data-test-tab="methods"
           }}

tests/unit/mixins/scroll-page-test.js

@@ -0,0 +1,12 @@
+import Ember from 'ember';
+import ScrollPageMixin from 'ember-api-docs/mixins/scroll-page';
+import { module, test } from 'qunit';
+
+module('Unit | Mixin | scroll page');
+
+// Replace this with your real tests.
+test('it works', function(assert) {
+  let ScrollPageObject = Ember.Object.extend(ScrollPageMixin);
+  let subject = ScrollPageObject.create();
+  assert.ok(subject);
+});