allow regex options on username site settings

lib/validators/regex_setting_validation.rb

@@ -0,0 +1,17 @@
+module RegexSettingValidation
+
+  def initialize_regex_opts(opts = {})
+    @regex = Regexp.new(opts[:regex]) if opts[:regex]
+    @regex_error = opts[:regex_error] || 'site_settings.errors.regex_mismatch'
+  end
+
+  def regex_match?(val)
+    if @regex && !(val =~ @regex)
+      @regex_fail = true
+      return false
+    end
+
+    true
+  end
+
+end

lib/validators/string_setting_validator.rb

@@ -1,8 +1,10 @@
 class StringSettingValidator
+
+  include RegexSettingValidation
+
   def initialize(opts = {})
     @opts = opts
-    @regex = Regexp.new(opts[:regex]) if opts[:regex]
-    @regex_error = opts[:regex_error] || 'site_settings.errors.regex_mismatch'
+    initialize_regex_opts(opts)
   end
 
   def valid_value?(val)
@@ -13,12 +15,7 @@ class StringSettingValidator
       return false
     end
 
-    if @regex && !(val =~ @regex)
-      @regex_fail = true
-      return false
-    end
-
-    true
+    regex_match?(val)
   end
 
   def error_message

lib/validators/username_setting_validator.rb

@@ -1,13 +1,21 @@
 class UsernameSettingValidator
+
+  include RegexSettingValidation
+
   def initialize(opts = {})
     @opts = opts
+    initialize_regex_opts(opts)
   end
 
   def valid_value?(val)
-    !val.present? || User.where(username: val).exists?
+    !val.present? || (User.where(username: val).exists? && regex_match?(val))
   end
 
   def error_message
-    I18n.t('site_settings.errors.invalid_username')
+    if @regex_fail
+      I18n.t(@regex_error)
+    else
+      I18n.t('site_settings.errors.invalid_username')
+    end
   end
 end