Add validates_format_of :without => /regexp/ option [Elliot Winkler, Peer Allan]

[#430 state:resolved]

  Example :

    validates_format_of :subdomain, :without => /www|admin|mail/

Signed-off-by: Pratik Naik <pratiknaik@gmail.com>

3 files changed, 64 insertions, 8 deletions

diff --git a/activemodel/CHANGELOG b/activemodel/CHANGELOG
index 142038cc87..26500568ee 100644
--- a/activemodel/CHANGELOG
+++ b/activemodel/CHANGELOG
@@ -1,5 +1,11 @@
 *Edge*
 
+* Add validates_format_of :without => /regexp/ option. #430 [Elliot Winkler, Peer Allan]
+
+  Example :
+
+      validates_format_of :subdomain, :without => /www|admin|mail/
+
 * Introduce validates_with to encapsulate attribute validations in a class.  #2630 [Jeff Dean]
 
 * Extracted from Active Record and Active Resource.
diff --git a/activemodel/lib/active_model/validations/format.rb b/activemodel/lib/active_model/validations/format.rb
index 6f3b668bf0..3b3dd4b827 100644
--- a/activemodel/lib/active_model/validations/format.rb
+++ b/activemodel/lib/active_model/validations/format.rb
@@ -1,22 +1,30 @@
 module ActiveModel
   module Validations
     module ClassMethods
-      # Validates whether the value of the specified attribute is of the correct form by matching it against the regular expression
-      # provided.
+      # Validates whether the value of the specified attribute is of the correct form, going by the regular expression provided.
+      # You can require that the attribute matches the regular expression:
       #
       #   class Person < ActiveRecord::Base
       #     validates_format_of :email, :with => /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\Z/i, :on => :create
       #   end
       #
+      # Alternatively, you can require that the specified attribute does _not_ match the regular expression:
+      #
+      #   class Person < ActiveRecord::Base
+      #     validates_format_of :email, :without => /NOSPAM/
+      #   end
+      #
       # Note: use <tt>\A</tt> and <tt>\Z</tt> to match the start and end of the string, <tt>^</tt> and <tt>$</tt> match the start/end of a line.
       #
-      # A regular expression must be provided or else an exception will be raised.
+      # You must pass either <tt>:with</tt> or <tt>:without</tt> as an option. In addition, both must be a regular expression,
+      # or else an exception will be raised.
       #
       # Configuration options:
       # * <tt>:message</tt> - A custom error message (default is: "is invalid").
       # * <tt>:allow_nil</tt> - If set to true, skips this validation if the attribute is +nil+ (default is +false+).
       # * <tt>:allow_blank</tt> - If set to true, skips this validation if the attribute is blank (default is +false+).
-      # * <tt>:with</tt> - The regular expression used to validate the format with (note: must be supplied!).
+      # * <tt>:with</tt> - Regular expression that if the attribute matches will result in a successful validation.
+      # * <tt>:without</tt> - Regular expression that if the attribute does not match will result in a successful validation.
       # * <tt>:on</tt> - Specifies when this validation is active (default is <tt>:save</tt>, other options <tt>:create</tt>, <tt>:update</tt>).
       # * <tt>:if</tt> - Specifies a method, proc or string to call to determine if the validation should
       #   occur (e.g. <tt>:if => :allow_validation</tt>, or <tt>:if => Proc.new { |user| user.signup_step > 2 }</tt>).  The
@@ -25,13 +33,26 @@ module ActiveModel
       #   not occur (e.g. <tt>:unless => :skip_validation</tt>, or <tt>:unless => Proc.new { |user| user.signup_step <= 2 }</tt>).  The
       #   method, proc or string should return or evaluate to a true or false value.
       def validates_format_of(*attr_names)
-        configuration = { :with => nil }
-        configuration.update(attr_names.extract_options!)
+        configuration = attr_names.extract_options!
+
+        unless configuration.include?(:with) ^ configuration.include?(:without)  # ^ == xor, or "exclusive or"
+          raise ArgumentError, "Either :with or :without must be supplied (but not both)"
+        end
 
-        raise(ArgumentError, "A regular expression must be supplied as the :with option of the configuration hash") unless configuration[:with].is_a?(Regexp)
+        if configuration[:with] && !configuration[:with].is_a?(Regexp)
+          raise ArgumentError, "A regular expression must be supplied as the :with option of the configuration hash"
+        end
+
+        if configuration[:without] && !configuration[:without].is_a?(Regexp)
+          raise ArgumentError, "A regular expression must be supplied as the :without option of the configuration hash"
+        end
 
         validates_each(attr_names, configuration) do |record, attr_name, value|
-          unless value.to_s =~ configuration[:with]
+          if configuration[:with] && value.to_s !~ configuration[:with]
+            record.errors.add(attr_name, :invalid, :default => configuration[:message], :value => value)
+          end
+
+          if configuration[:without] && value.to_s =~ configuration[:without]
             record.errors.add(attr_name, :invalid, :default => configuration[:message], :value => value)
           end
         end
diff --git a/activemodel/test/cases/validations/format_validation_test.rb b/activemodel/test/cases/validations/format_validation_test.rb
index 2c06a9dd02..e19e4bf7b3 100644
--- a/activemodel/test/cases/validations/format_validation_test.rb
+++ b/activemodel/test/cases/validations/format_validation_test.rb
@@ -71,6 +71,35 @@ class PresenceValidationTest < ActiveModel::TestCase
     assert_equal ["can't be Invalid title"], t.errors[:title]
   end
 
+  def test_validate_format_with_not_option
+    Topic.validates_format_of(:title, :without => /foo/, :message => "should not contain foo")
+    t = Topic.new
+
+    t.title = "foobar"
+    t.valid?
+    assert_equal ["should not contain foo"], t.errors[:title]
+
+    t.title = "something else"
+    t.valid?
+    assert_equal [], t.errors[:title]
+  end
+
+  def test_validate_format_of_without_any_regexp_should_raise_error
+    assert_raise(ArgumentError) { Topic.validates_format_of(:title) }
+  end
+
+  def test_validates_format_of_with_both_regexps_should_raise_error
+    assert_raise(ArgumentError) { Topic.validates_format_of(:title, :with => /this/, :without => /that/) }
+  end
+
+  def test_validates_format_of_when_with_isnt_a_regexp_should_raise_error
+    assert_raise(ArgumentError) { Topic.validates_format_of(:title, :with => "clearly not a regexp") }
+  end
+
+  def test_validates_format_of_when_not_isnt_a_regexp_should_raise_error
+    assert_raise(ArgumentError) { Topic.validates_format_of(:title, :without => "clearly not a regexp") }
+  end
+
   def test_validates_format_of_with_custom_error_using_quotes
     repair_validations(Developer) do
       Developer.validates_format_of :name, :with => /^(A-Z*)$/, :message=> "format 'single' and \"double\" quotes"