Add validates_confirmation_of matcher

lib/shoulda/matchers/active_model.rb

@@ -8,6 +8,7 @@ require 'shoulda/matchers/active_model/validate_presence_of_matcher'
 require 'shoulda/matchers/active_model/validate_format_of_matcher'
 require 'shoulda/matchers/active_model/validate_uniqueness_of_matcher'
 require 'shoulda/matchers/active_model/validate_acceptance_of_matcher'
+require 'shoulda/matchers/active_model/validate_confirmation_of_matcher'
 require 'shoulda/matchers/active_model/validate_numericality_of_matcher'
 require 'shoulda/matchers/active_model/allow_mass_assignment_of_matcher'
 

lib/shoulda/matchers/active_model/validate_confirmation_of_matcher.rb

@@ -0,0 +1,63 @@
+module Shoulda # :nodoc:
+  module Matchers
+    module ActiveModel # :nodoc:
+      # Ensures that the model's attribute matches confirmation
+      #
+      # Example:
+      #   it { should validate_confirmation_of(:password) }
+      #
+      def validate_confirmation_of(attr)
+        ValidateConfirmationOfMatcher.new(attr)
+      end
+
+      class ValidateConfirmationOfMatcher < ValidationMatcher # :nodoc:
+        include Helpers
+
+        def initialize(attribute)
+          @attribute = attribute
+          @confirmation = "#{attribute}_confirmation"
+        end
+
+        def with_message(message)
+          @message = message if message
+          self
+        end
+
+        def description
+          "require #{@base_attribute} to match #{@attribute}"
+        end
+
+        def matches?(subject)
+          super(subject)
+          @message ||= :confirmation
+
+          disallows_different_value &&
+            allows_same_value &&
+            allows_missing_confirmation
+        end
+
+        private
+
+        def disallows_different_value
+          set_confirmation("some value")
+          matches = disallows_value_of("different value", @message)
+        end
+
+        def allows_same_value
+          set_confirmation("same value")
+          allows_value_of("same value", @message)
+        end
+
+        def allows_missing_confirmation
+          set_confirmation(nil)
+          allows_value_of("any value", @message)
+        end
+
+        def set_confirmation(val)
+          setter = :"#{@confirmation}="
+          @subject.send(setter, val) if @subject.respond_to?(setter)
+        end
+      end
+    end
+  end
+end

spec/shoulda/active_model/validate_confirmation_of_matcher_spec.rb

@@ -0,0 +1,48 @@
+require 'spec_helper'
+
+describe Shoulda::Matchers::ActiveModel::ValidateConfirmationOfMatcher do
+
+  context "an attribute which needs confirmation" do
+    before do
+      define_model(:example, :attr => :string) do
+        validates_confirmation_of :attr
+      end
+      @model = Example.new
+    end
+
+    it "should require confirmation of that attribute" do
+      @model.should validate_confirmation_of(:attr)
+    end
+
+    it "should not override the default message with a blank" do
+      @model.should validate_confirmation_of(:attr).with_message(nil)
+    end
+  end
+
+  context "an attribute which must be confirmed with a custom message" do
+    before do
+      define_model :example, :attr => :string do
+        validates_confirmation_of :attr, :message => 'custom'
+      end
+      @model = Example.new
+    end
+
+    it "should require confirmation of that attribute with that message" do
+      @model.should validate_confirmation_of(:attr).with_message(/custom/)
+    end
+
+    it "should not require confirmation of that attribute with another message" do
+      @model.should_not validate_confirmation_of(:attr)
+    end
+  end
+
+  context "an attribute which doesn't need confirmation" do
+    before do
+      @model = define_model(:example, :attr => :string).new
+    end
+
+    it "should not require confirmation of that attribute" do
+      @model.should_not validate_confirmation_of(:attr)
+    end
+  end
+end