Add deprecation for Route#renderTemplate

packages/@ember/-internals/routing/lib/system/route.ts

@@ -1507,6 +1507,17 @@ class Route extends EmberObject implements IRoute {
     @public
   */
   renderTemplate(_controller: any, _model: {}) {
+    if (this.renderTemplate !== Route.prototype.renderTemplate) {
+      deprecate('Usage of `renderTemplate` is deprecated.', false, {
+        id: 'route-render-template',
+        until: '4.0.0',
+        url: 'https://deprecations.emberjs.com/v3.x/#toc_route-render-template',
+        for: 'ember-source',
+        since: {
+          enabled: '3.27.0',
+        },
+      });
+    }
     // eslint-disable-line no-unused-vars
     this.render();
   }

packages/ember-testing/tests/acceptance_test.js

@@ -51,6 +51,7 @@ if (!jQueryDisabled) {
             'route:posts',
             Route.extend({
               renderTemplate() {
+                expectDeprecation('Usage of `renderTemplate` is deprecated.');
                 testContext.currentRoute = 'posts';
                 this._super(...arguments);
               },
@@ -73,6 +74,7 @@ if (!jQueryDisabled) {
             'route:comments',
             Route.extend({
               renderTemplate() {
+                expectDeprecation('Usage of `renderTemplate` is deprecated.');
                 testContext.currentRoute = 'comments';
                 this._super(...arguments);
               },
@@ -125,7 +127,7 @@ if (!jQueryDisabled) {
       }
 
       [`@test helpers can be chained with then`](assert) {
-        assert.expect(6);
+        assert.expect(8);
 
         window
           .visit('/posts')
@@ -164,7 +166,7 @@ if (!jQueryDisabled) {
       }
 
       [`@test helpers can be chained to each other (legacy)`](assert) {
-        assert.expect(7);
+        assert.expect(10);
 
         window
           .visit('/posts')
@@ -192,7 +194,7 @@ if (!jQueryDisabled) {
       }
 
       [`@test helpers don't need to be chained`](assert) {
-        assert.expect(5);
+        assert.expect(8);
 
         window.visit('/posts');
 
@@ -219,7 +221,7 @@ if (!jQueryDisabled) {
       }
 
       [`@test Nested async helpers`](assert) {
-        assert.expect(5);
+        assert.expect(8);
 
         window.visit('/posts');
 
@@ -247,7 +249,7 @@ if (!jQueryDisabled) {
       }
 
       [`@test Multiple nested async helpers`](assert) {
-        assert.expect(3);
+        assert.expect(5);
 
         window.visit('/posts');
 
@@ -270,7 +272,7 @@ if (!jQueryDisabled) {
       }
 
       [`@test Helpers nested in thens`](assert) {
-        assert.expect(5);
+        assert.expect(8);
 
         window.visit('/posts').then(() => {
           window.click('a:first', '#comments-link');
@@ -311,7 +313,7 @@ if (!jQueryDisabled) {
       }
 
       [`@test Unhandled exceptions are logged via Ember.Test.adapter#exception`](assert) {
-        assert.expect(2);
+        assert.expect(3);
 
         console.error = () => {}; // eslint-disable-line no-console
         let asyncHandled;
@@ -343,7 +345,7 @@ if (!jQueryDisabled) {
       [`@test Unhandled exceptions in 'andThen' are logged via Ember.Test.adapter#exception`](
         assert
       ) {
-        assert.expect(1);
+        assert.expect(2);
 
         console.error = () => {}; // eslint-disable-line no-console
         Test.adapter = QUnitAdapter.create({
@@ -364,7 +366,7 @@ if (!jQueryDisabled) {
       }
 
       [`@test should not start routing on the root URL when visiting another`](assert) {
-        assert.expect(4);
+        assert.expect(5);
 
         window.visit('/posts');
 
@@ -427,7 +429,7 @@ if (!jQueryDisabled) {
       }
 
       [`@test visiting a URL that causes another transition should yield the correct URL`](assert) {
-        assert.expect(2);
+        assert.expect(3);
 
         window.visit('/redirect');
 
@@ -439,7 +441,7 @@ if (!jQueryDisabled) {
       [`@test visiting a URL and then visiting a second URL with a transition should yield the correct URL`](
         assert
       ) {
-        assert.expect(3);
+        assert.expect(5);
 
         window.visit('/posts');
 

packages/ember/tests/routing/template_rendering_test.js

@@ -305,7 +305,7 @@ moduleFor(
     }
 
     ['@test Generated names can be customized when providing routes with dot notation'](assert) {
-      assert.expect(4);
+      assert.expect(5);
 
       this.addTemplate('index', '<div>Index</div>');
       this.addTemplate('application', "<h1>Home</h1><div class='main'>{{outlet}}</div>");
@@ -325,6 +325,7 @@ moduleFor(
         'route:foo',
         Route.extend({
           renderTemplate() {
+            expectDeprecation('Usage of `renderTemplate` is deprecated.');
             assert.ok(true, 'FooBarRoute was called');
             return this._super(...arguments);
           },