mailer previews for NullMail instances. Closes #19849.

rails · Apr 27, 2015 · 95c2734 · 95c2734
1 parent 503a80a
commit 95c2734
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diff --git a/actionmailer/CHANGELOG.md b/actionmailer/CHANGELOG.md
@@ -1,3 +1,10 @@
+*   Mailer previews no longer crash when the `mail` method wasn't called
+    (`NullMail`).
+
+    Fixes #19849.
+
+    *Yves Senn*
+
 *   Make sure labels and values line up in mailer previews.
 
     *Yves Senn*

diff --git a/actionmailer/lib/action_mailer/base.rb b/actionmailer/lib/action_mailer/base.rb
@@ -596,6 +596,7 @@ def process(method_name, *args) #:nodoc:
 
     class NullMail #:nodoc:
       def body; '' end
+      def header; {} end
 
       def respond_to?(string, include_all=false)
         true

diff --git a/railties/lib/rails/mailers_controller.rb b/railties/lib/rails/mailers_controller.rb
@@ -16,10 +16,10 @@ def preview
       @page_title = "Mailer Previews for #{@preview.preview_name}"
       render action: 'mailer'
     else
-      email = File.basename(params[:path])
+      @email_action = File.basename(params[:path])
 
-      if @preview.email_exists?(email)
-        @email = @preview.call(email)
+      if @preview.email_exists?(@email_action)
+        @email = @preview.call(@email_action)
 
         if params[:part]
           part_type = Mime::Type.lookup(params[:part])
@@ -28,14 +28,14 @@ def preview
             response.content_type = part_type
             render text: part.respond_to?(:decoded) ? part.decoded : part
           else
-            raise AbstractController::ActionNotFound, "Email part '#{part_type}' not found in #{@preview.name}##{email}"
+            raise AbstractController::ActionNotFound, "Email part '#{part_type}' not found in #{@preview.name}##{@email_action}"
           end
         else
           @part = find_preferred_part(request.format, Mime::HTML, Mime::TEXT)
           render action: 'email', layout: false, formats: %w[html]
         end
       else
-        raise AbstractController::ActionNotFound, "Email '#{email}' not found in #{@preview.name}"
+        raise AbstractController::ActionNotFound, "Email '#{@email_action}' not found in #{@preview.name}"
       end
     end
   end

diff --git a/railties/lib/rails/templates/rails/mailers/email.html.erb b/railties/lib/rails/templates/rails/mailers/email.html.erb
@@ -103,7 +103,16 @@
   </dl>
 </header>
 
-<iframe seamless name="messageBody" src="?part=<%= Rack::Utils.escape(@part.mime_type) %>"></iframe>
+<% if @part.mime_type %>
+  <iframe seamless name="messageBody" src="?part=<%= Rack::Utils.escape(@part.mime_type) %>"></iframe>
+<% else %>
+  <p>
+    You are trying to preview an email without content.
+    Make sure to call the <em>mail</em> method in <em><%= @preview.preview_name %>#<%= @email_action %></em>.
+  </p>
+  <strong>Message (debug):</strong>
+  <%= debug @email %>
+<% end %>
 
 </body>
 </html>
diff --git a/railties/test/application/mailer_previews_test.rb b/railties/test/application/mailer_previews_test.rb
@@ -327,6 +327,33 @@ def foo
       assert_match "Email &#39;bar&#39; not found in NotifierPreview", last_response.body
     end
 
+    test "mailer preview NullMail" do
+      mailer 'notifier', <<-RUBY
+        class Notifier < ActionMailer::Base
+          default from: "from@example.com"
+
+          def foo
+            # does not call +mail+
+          end
+        end
+      RUBY
+
+      mailer_preview 'notifier', <<-RUBY
+        class NotifierPreview < ActionMailer::Preview
+          def foo
+            Notifier.foo
+          end
+        end
+      RUBY
+
+      app('development')
+
+      get "/rails/mailers/notifier/foo"
+      assert_match "You are trying to preview an email without content.", last_response.body
+      assert_match "notifier#foo", last_response.body
+      assert_match "ActionMailer::Base::NullMail", last_response.body
+    end
+
     test "mailer preview email part not found" do
       mailer 'notifier', <<-RUBY
         class Notifier < ActionMailer::Base