Add Render The Response Body In Controller Specs a rails til

Author: jbranchaud

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://tinyletter.com/jbranchaud).
 
-_1033 TILs and counting..._
+_1034 TILs and counting..._
 
 ---
 
@@ -667,6 +667,7 @@ _1033 TILs and counting..._
 - [Read-Only Models](rails/read-only-models.md)
 - [Remove The Default Value On A Column](rails/remove-the-default-value-on-a-column.md)
 - [Render An Alternative ActionMailer Template](rails/render-an-alternative-action-mailer-template.md)
+- [Render The Response Body In Controller Specs](rails/render-the-response-body-in-controller-specs.md)
 - [Rescue From](rails/rescue-from.md)
 - [Retrieve An Object If It Exists](rails/retrieve-an-object-if-it-exists.md)
 - [Rounding Numbers With Precision](rails/rounding-numbers-with-precision.md)

rails/render-the-response-body-in-controller-specs.md

@@ -0,0 +1,35 @@
+# Render The Response Body In Controller Specs
+
+Controller specs skip the rendering of views by default. If you want to inspect
+some aspect of what is rendered in the HTML body of a response
+(`response.body`), you can include the `render_views` directive in that spec.
+
+```ruby
+require 'rails_helper'
+
+RSpec.describe DashboardController do
+  describe '#index' do
+    render_views
+
+    context 'when there is a signed in user' do
+      it 'includes their email' do
+        user = User.create(email: 'user@example.com')
+
+        sign_in(user)
+
+        get :index
+
+        expect(response.body).to include('user@example.com')
+      end
+    end
+  end
+end
+```
+
+The `render_views` directive call can go at the top of a spec, and all views
+for all tests will be rendered. Or you can place it in the nested contexts only
+where it is needed.
+
+View rendering is skipped by default in an effort to keep tests speedy. To not
+unnecessarily slow down your test suite, make sure to use it sparingly and only
+in tests where you are actually inspecting `response.body`.