Add Mutant::Matcher::Chain

lib/mutant/matcher/chain.rb

@@ -0,0 +1,50 @@
+module Mutant
+  class Matcher
+    # A chain of matchers
+    class Chain < self
+      include Equalizer.new(:matchers)
+
+      # Enumerate subjects
+      #
+      # @return [Enumerator<Subject]
+      #   returns subject enumerator if no block given
+      #
+      # @return [self]
+      #   returnns self otherwise
+      #
+      # @api private
+      #
+      def each(&block)
+        return to_enum unless block_given?
+
+        @matchers.each do |matcher|
+          matcher.each(&block)
+        end
+
+        self
+      end
+
+      # Return the chain of matchers
+      #
+      # @return [Enumerable<Chain>]
+      #
+      # @api private
+      #
+      def matchers; @matchers; end
+
+    private
+
+      # Initialize chain matcher
+      #
+      # @param [Enumerable<Matcher>] matchers
+      #
+      # @return [undefined]
+      #
+      # @api private
+      #
+      def initialize(matchers)
+        @matchers = matchers
+      end
+    end
+  end
+end

spec/unit/mutant/matcher/chain/each_spec.rb

@@ -0,0 +1,28 @@
+require 'spec_helper'
+
+describe Mutant::Matcher::Chain, '#each' do
+  subject { object.each { |entry| yields << entry } }
+
+  let(:object) { described_class.new(matchers) }
+
+  let(:matchers) { [matcher_a, matcher_b] }
+
+  let(:matcher_a) { mock('Matcher A') }
+  let(:matcher_b) { mock('Matcher B') }
+
+  let(:subject_a) { mock('Subject A') }
+  let(:subject_b) { mock('Subject B') }
+  
+  before do
+    matcher_a.stub(:each).and_yield(subject_a).and_return(matcher_a)
+    matcher_b.stub(:each).and_yield(subject_b).and_return(matcher_b)
+  end
+
+  it_should_behave_like 'an #each method'
+
+  let(:yields) { [] }
+
+  it 'should yield subjects' do
+    expect { subject }.to change { yields }.from([]).to([subject_a, subject_b])
+  end
+end

spec/unit/mutant/matcher/chain/matchers_spec.rb

@@ -0,0 +1,12 @@
+require 'spec_helper'
+
+describe Mutant::Matcher::Chain, '#matchers' do
+  subject { object.matchers }
+
+  let(:object)   { described_class.new(matchers) }
+  let(:matchers) { mock('Matchers')              } 
+
+  it { should be(matchers) }
+
+  it_should_behave_like 'an idempotent method'
+end