add a test for customize theme controller

test/javascripts/admin/controllers/admin-customize-themes-test.js.es6

@@ -0,0 +1,32 @@
+import { mapRoutes } from 'discourse/mapping-router';
+import Theme from 'admin/models/theme';
+
+moduleFor('controller:admin-customize-themes', {
+  setup() {
+    this.registry.register('router:main', mapRoutes());
+  },
+  needs: ['controller:adminUser']
+});
+
+test("can list sorted themes", function() {
+
+  const defaultTheme = Theme.create({id: 2, 'default': true, name: 'default'});
+  const userTheme = Theme.create({id: 3, 'user_selectable': true, name: 'name'});
+  const strayTheme1 = Theme.create({id: 4, name: 'stray1'});
+  const strayTheme2 = Theme.create({id: 5, name: 'stray2'});
+
+  const controller = this.subject({
+    model:
+      {
+        content: [strayTheme2, strayTheme1, userTheme, defaultTheme]
+      }
+  });
+
+
+  deepEqual(controller.get('sortedThemes').map(t=>t.get('name')), [
+    defaultTheme,
+    userTheme,
+    strayTheme1,
+    strayTheme2
+  ].map(t=>t.get('name')), "sorts themes correctly");
+});