check for template

spec/mailers/user_notifications_spec.rb

@@ -35,6 +35,10 @@ describe UserNotifications do
       expect(subject.body).to be_present
     end
 
+    it "does not use the layout" do
+      expect(subject.html_part.to_s.scan(/<meta name="viewport" content="width=device-width, initial-scale=1.0">/).count).to eq(0)
+    end
+
   end
 
   describe ".forgot_password" do
@@ -48,6 +52,10 @@ describe UserNotifications do
       expect(subject.body).to be_present
     end
 
+    it "does not use the layout" do
+      expect(subject.html_part.to_s.scan(/<meta name="viewport" content="width=device-width, initial-scale=1.0">/).count).to eq(0)
+    end
+
   end
 
   describe '.digest' do
@@ -77,6 +85,10 @@ describe UserNotifications do
         expect(subject.text_part.body.to_s).to be_present
       end
 
+      it "uses the layout" do
+        expect(subject.html_part.to_s.scan(/<meta name="viewport" content="width=device-width, initial-scale=1.0">/).count).to eq(1)
+      end
+
       it "includes email_prefix in email subject instead of site title" do
         SiteSetting.email_prefix = "Try Discourse"
         SiteSetting.title = "Discourse Meta"
@@ -104,6 +116,8 @@ describe UserNotifications do
                                              notification_type: notification.notification_type,
                                              notification_data_hash: notification.data_hash
                                            )
+      # meta tag should be present from the layout
+      expect(mail.html_part.to_s.scan(/<meta name="viewport" content="width=device-width, initial-scale=1.0">/).count).to eq(1)
 
       # from should include full user name
       expect(mail[:from].display_names).to eql(['John Doe'])
@@ -156,6 +170,9 @@ describe UserNotifications do
                                            notification_data_hash: notification.data_hash
                                           )
 
+      # meta tag should be present from the layout
+      expect(mail.html_part.to_s.scan(/<meta name="viewport" content="width=device-width, initial-scale=1.0">/).count).to eq(1)
+
       # from should not include full user name if "show user full names" is disabled
       expect(mail[:from].display_names).to_not eql(['John Doe'])
 
@@ -193,6 +210,9 @@ describe UserNotifications do
         notification_data_hash: notification.data_hash
       )
 
+      # meta tag should be present from the layout
+      expect(mail.html_part.to_s.scan(/<meta name="viewport" content="width=device-width, initial-scale=1.0">/).count).to eq(1)
+
       # from should include username if full user name is not provided
       expect(mail[:from].display_names).to eql(['john'])