2 files changed, 21 insertions, 1 deletions
diff --git a/railties/lib/rails/generators/test_unit/mailer/mailer_generator.rb b/railties/lib/rails/generators/test_unit/mailer/mailer_generator.rb
index 3334b189bf..85dee1a066 100644
--- a/railties/lib/rails/generators/test_unit/mailer/mailer_generator.rb
+++ b/railties/lib/rails/generators/test_unit/mailer/mailer_generator.rb
@@ -4,11 +4,18 @@ module TestUnit # :nodoc:
   module Generators # :nodoc:
     class MailerGenerator < Base # :nodoc:
       argument :actions, type: :array, default: [], banner: "method method"
-      check_class_collision suffix: "Test"
+
+      def check_class_collision
+        class_collisions "#{class_name}Test", "#{class_name}Preview"
+      end
 
       def create_test_files
         template "functional_test.rb", File.join('test/mailers', class_path, "#{file_name}_test.rb")
       end
+
+      def create_preview_files
+        template "preview.rb", File.join('test/mailers/previews', class_path, "#{file_name}_preview.rb")
+      end
     end
   end
 end
diff --git a/railties/lib/rails/generators/test_unit/mailer/templates/preview.rb b/railties/lib/rails/generators/test_unit/mailer/templates/preview.rb
new file mode 100644
index 0000000000..3bfd5426e8
--- /dev/null
+++ b/railties/lib/rails/generators/test_unit/mailer/templates/preview.rb
@@ -0,0 +1,13 @@
+<% module_namespacing do -%>
+# Preview all emails at http://localhost:3000/rails/mailers/<%= file_path %>
+class <%= class_name %>Preview < ActionMailer::Preview
+<% actions.each do |action| -%>
+
+  # Preview this email at http://localhost:3000/rails/mailers/<%= file_path %>/<%= action %>
+  def <%= action %>
+    <%= class_name %>.<%= action %>
+  end
+<% end -%>
+
+end
+<% end -%>