add ensure_exclusion_of

lib/shoulda/matchers/active_model.rb

@@ -3,6 +3,7 @@ require 'shoulda/matchers/active_model/validation_matcher'
 require 'shoulda/matchers/active_model/allow_value_matcher'
 require 'shoulda/matchers/active_model/ensure_length_of_matcher'
 require 'shoulda/matchers/active_model/ensure_inclusion_of_matcher'
+require 'shoulda/matchers/active_model/ensure_exclusion_of_matcher'
 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'

lib/shoulda/matchers/active_model/ensure_exclusion_of_matcher.rb

@@ -0,0 +1,70 @@
+module Shoulda # :nodoc:
+  module Matchers
+    module ActiveModel # :nodoc:
+
+      # Ensure that the attribute's value is not in the range specified
+      #
+      # Options:
+      # * <tt>in_range</tt> - the range of not allowed values for this attribute
+      # * <tt>with_message</tt> - value the test expects to find in
+      #   <tt>errors.on(:attribute)</tt>. Regexp or string. Defaults to the
+      #   translation for :exclusion.
+      #
+      # Example:
+      #   it { should ensure_exclusion_of(:age).in_range(30..60) }
+      #
+      def ensure_exclusion_of(attr)
+        EnsureExclusionOfMatcher.new(attr)
+      end
+
+      class EnsureExclusionOfMatcher < ValidationMatcher # :nodoc:
+
+        def in_range(range)
+          @range = range
+          @minimum = range.first
+          @maximum = range.last
+          self
+        end
+
+        def with_message(message)
+          @expected_message = message if message
+          self
+        end
+
+        def description
+          "ensure exclusion of #{@attribute} in #{@range.inspect}"
+        end
+
+        def matches?(subject)
+          super(subject)
+
+          @expected_message ||= :exclusion
+
+          allows_lower_value &&
+            disallows_minimum_value &&
+            allows_higher_value &&
+            disallows_maximum_value
+        end
+
+        private
+
+        def allows_lower_value
+          @minimum == 0 || allows_value_of(@minimum - 1, @expected_message)
+        end
+
+        def allows_higher_value
+          allows_value_of(@maximum + 1, @expected_message)
+        end
+
+        def disallows_minimum_value
+          disallows_value_of(@minimum, @expected_message)
+        end
+
+        def disallows_maximum_value
+          disallows_value_of(@maximum, @expected_message)
+        end
+      end
+
+    end
+  end
+end

spec/shoulda/active_model/ensure_exclusion_of_matcher_spec.rb

@@ -0,0 +1,57 @@
+require 'spec_helper'
+
+describe Shoulda::Matchers::ActiveModel::EnsureExclusionOfMatcher do
+
+  context "an attribute which must be excluded of a range" do
+    before do
+      @model = define_model(:example, :attr => :integer) do
+        validates_exclusion_of :attr, :in => 2..5
+      end.new
+    end
+
+    it "should accept ensuring the correct range" do
+      @model.should ensure_exclusion_of(:attr).in_range(2..5)
+    end
+
+    it "should reject ensuring excluded value" do
+      @model.should_not ensure_exclusion_of(:attr).in_range(2..6)
+    end
+
+    it "should not override the default message with a blank" do
+      @model.should ensure_exclusion_of(:attr).in_range(2..5).with_message(nil)
+    end
+  end
+
+  context "an attribute with a custom ranged value validation" do
+    before do
+      @model = define_model(:example, :attr => :string) do
+        validates_exclusion_of :attr, :in => 2..4, :message => 'not good'
+
+      end.new
+    end
+
+    it "should accept ensuring the correct range" do
+      @model.should ensure_exclusion_of(:attr).in_range(2..4).with_message(/not good/)
+    end
+  end
+
+  context "an attribute with custom range validations" do
+    before do
+      define_model :example, :attr => :integer do
+        validate :custom_validation
+        def custom_validation
+          if attr >= 2 && attr <= 5
+            errors.add(:attr, 'shoud be out of this range')
+          end
+        end
+      end
+      @model = Example.new
+    end
+
+    it "should accept ensuring the correct range and messages" do
+      @model.should ensure_exclusion_of(:attr).in_range(2..5).with_message(/shoud be out of this range/)
+    end
+
+  end
+
+end