Add contact flash

lib/contact_form.rb

@@ -6,6 +6,8 @@ class ContactForm
     "message" => 5000
   }.freeze
 
+  EMAIL_PATTERN = /\A[A-Z0-9!#$%&'*+\/=?^_`{|}~-]+(?:\.[A-Z0-9!#$%&'*+\/=?^_`{|}~-]+)*@[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?(?:\.[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?)+\z/i
+
   def initialize(params)
     @params = params
   end
@@ -26,7 +28,8 @@ class ContactForm
 
     return false unless fields_valid
 
-    email_valid = @params["email"].strip.match?(/\A[^\s@]+@[^\s@]+\.[^\s@]+\z/)
+    email_valid = @params["email"].strip.match?(EMAIL_PATTERN)
+
     headers_valid = %w[name subject].none? do |key|
       @params[key].match?(/[\r\n]/)
     end