* filtering result and validator based on attribute

* bump to 0.0.5

README.md

@@ -50,6 +50,7 @@ result.valid? # => true
 
 result = validator.run(:login)
 result.valid? # => false
+rresult.on(:password) # => #<Set: {#<Knight::Error rule=#<Knight::Rule::Presence attribute_name=:password>>}>esult.valid? # => true
 
 user = User.new('', 'password')
 validator = UserValidator.new(user)

lib/knight/result.rb

@@ -80,7 +80,7 @@ def errors
     #
     # @api public
     def on(attribute)
-      errors.select { |error| error.attribute_name == attribute }
+      errors.select { |error| error.attribute_name == attribute }.to_set
     end
 
     private

lib/knight/rule.rb

@@ -5,7 +5,7 @@ module Knight
   # An abstract class of a rule
   class Rule
     include AbstractType
-    include Equalizer.new(:attribute_name, :options)
+    include Equalizer.new(:attribute_name)
 
     DEFAULT_MESSAGE  = ''.freeze
 

lib/knight/validator.rb

@@ -59,5 +59,40 @@ def add(rule)
     def run(resource)
       Result.new(resource, rules)
     end
+
+    # Run the validator on specific attribute
+    #
+    # @example
+    #   user = User.new(username: 'john')
+    #
+    #   validator = Validator.new(Rule::Presence.new(:username))
+    #   validator.run_on(user, :username)
+    #
+    # @param [Object] resource
+    # @param [Symbol] attribute
+    #
+    # @return [Result]
+    #
+    # @api public
+    def run_on(resource, attribute)
+      Result.new(resource, on(attribute))
+    end
+
+    # Run the rules on specific attribute
+    #
+    # @example
+    #   user = User.new(username: 'john')
+    #
+    #   validator = Validator.new(Rule::Presence.new(:username))
+    #   validator.on(:username)
+    #
+    # @param [Symbol] attribute
+    #
+    # @return [Set(Rules)]
+    #
+    # @api public
+    def on(attribute)
+      rules.select { |rule| rule.attribute_name == attribute }.to_set
+    end
   end
 end

lib/knight/version.rb

@@ -1,5 +1,5 @@
 # encoding: utf-8
 
 module Knight
-  VERSION = '0.0.4'
+  VERSION = '0.0.5'
 end

spec/unit/knight/result/errors_spec.rb

@@ -32,6 +32,8 @@ def initialize(foo)
     let(:rules) do
       [Rule::Presence.new(:foo), Rule::ExactLength.new(:bar, 3)]
     end
+    let(:resource) { double('resource') }
+    it { should be_instance_of(Set) }
 
     context 'empty string' do
       let(:resource) { klass.new('') }

spec/unit/knight/result/on_spec.rb

@@ -26,6 +26,7 @@ def initialize(foo)
     ]
   end
 
+  it { should be_instance_of(Set) }
   specify { expect(subject.size).to eql(1) }
   specify { expect(result.errors.size).to eql(2) }
 end

spec/unit/knight/validator/add_spec.rb

@@ -8,9 +8,11 @@
   let(:validator) { described_class.new(rule1) }
   let(:rule1) { Rule::ExactLength.new(:username, 10) }
   let(:rule2) { Rule::Presence.new(:username) }
+  let(:rule3) { Rule::Presence.new(:username, message: 'message') }
 
   before do
     validator.add(rule2)
+    validator.add(rule3)
     validator.add(nil)
   end
 

spec/unit/knight/validator/on_spec.rb

@@ -0,0 +1,13 @@
+# encoding: utf-8
+
+require 'spec_helper'
+
+describe Validator, '#on' do
+  subject { validator.on(:username) }
+
+  let(:validator) { described_class.new(*rules) }
+  let(:rules) { [Rule::Presence.new(:username), Rule::Presence.new(:password)] }
+
+  it { should be_instance_of(Set) }
+  specify { expect(subject.size).to eql(1) }
+end

spec/unit/knight/validator/run_on_spec.rb

@@ -0,0 +1,17 @@
+# encoding: utf-8
+
+require 'spec_helper'
+
+describe Validator, '#run_on' do
+  subject { validator.run_on(resource, attribute) }
+
+  let(:validator) { described_class.new }
+  let(:resource) { double('resource') }
+  let(:attribute) { :username }
+
+  it do
+    validator.should_receive(:on).with(attribute)
+    should be_instance_of(Result)
+  end
+  its(:resource) { should eql(resource) }
+end