add test flash

app/helpers/users_helper.rb

 module UsersHelper
   # Returns the Gravatar for the given user.
-  def gravatar_for(user)
+  def gravatar_for(user, options = { size: 80 })
     gravatar_id = Digest::MD5::hexdigest(user.email.downcase)
-    gravatar_url = "https://secure.gravatar.com/avatar/#{gravatar_id}"
+		size = options[:size]
+    gravatar_url = "https://secure.gravatar.com/avatar/#{gravatar_id}?s=#{size}"
     image_tag(gravatar_url, alt: user.name, class: "gravatar")
   end
 end

app/views/layouts/application.html.erb

@@ -12,7 +12,8 @@
     <%= render 'layouts/header' %>
     <div class="container">
       <% flash.each do |message_type, message| %>
-        <div class="alert alert-<%= message_type %>"><%= message %></div>
+        <!-- <div class="alert alert-<%= message_type %>"><%= message %></div> -->
+				<%= content_tag(:div, message, class: "alert alert-#{message_type}") %>
       <% end %>
       <%= yield %>
       <%= render 'layouts/footer' %>

test/integration/users_signup_test.rb

@@ -7,6 +7,8 @@ class UsersSignupTest < ActionDispatch::IntegrationTest
       post users_path, user: {name: "", email: "user@invalid", password: "foo", password_confirmation: "bar"}
     end
     assert_template 'users/new'
+		assert_select 'div#error_explanation'
+		assert_select 'div.alert'
   end
 
   test "valid signup information" do
@@ -15,5 +17,6 @@ class UsersSignupTest < ActionDispatch::IntegrationTest
       post_via_redirect users_path, user: {name: "Example User", email: "user@example.com", password: "password", password_confirmation: "password"}
     end
     assert_template 'users/show'
+		assert_not flash.empty?
   end
 end