Fixing constant to disallow period at beginning or end

lib/email_repair/constants.rb

@@ -1,12 +1,21 @@
 module EmailRepair
   class Constants
-    def self.email_regex
-      local_part_regex = "[#{email_local_part_valid_chars}]+"
-      /#{local_part_regex}@(?:[a-z0-9\-]+\.)+(?:museum|travel|[a-z]{2,4})/
-    end
+    class << self
+      def email_regex
+        local_part_regex = "[#{valid_chars}]" \
+          "([#{valid_chars_with_dot}]*[#{valid_chars}])?"
+        /#{local_part_regex}@(?:[a-z0-9\-]+\.)+(?:museum|travel|[a-z]{2,4})/
+      end
+
+    private
+
+      def valid_chars_with_dot
+        "#{valid_chars}\."
+      end
 
-    def self.email_local_part_valid_chars
-      'a-z0-9_\.%\+\-\''
+      def valid_chars
+        'a-z0-9_%\+\-\''
+      end
     end
   end
 end

spec/lib/email_repair/mechanic_spec.rb

@@ -2,7 +2,6 @@
 
 module EmailRepair
   describe Mechanic, '#repair' do
-
     let(:mechanic) { Mechanic.new }
 
     it 'returns clean emails as is' do
@@ -26,7 +25,7 @@ module EmailRepair
     end
 
     it 'returns nil for strings that have no email' do
-      ['', ' ', 'NOT AN EMAIL', 'b at b dot com'].each do |not_email|
+      ['', ' ', 'NOT AN EMAIL', 'b at b dot com', 'a.@com'].each do |not_email|
         expect(mechanic.repair(not_email)).to be_nil
       end
     end
@@ -107,6 +106,7 @@ module EmailRepair
         'one@email.com,another@email.com' => 'one@email.com',
         'one@email.com;another@email.com' => 'one@email.com',
         '<one@email.com>' => 'one@email.com',
+        '.one@email.com' => 'one@email.com',
       }
 
       dirty_emails.each do |in_mail, out_mail|
@@ -125,6 +125,5 @@ module EmailRepair
         expect(mechanic.repair(in_mail)).to eq out_mail
       end
     end
-
   end
 end