Add specs for the consistent ordering of the files to run.

These are for #660.

spec/rspec/core/configuration_spec.rb

@@ -316,6 +316,40 @@ module RSpec::Core
           config.files_to_run.should be_empty
         end
       end
+
+      def test_files_to_run_ordering
+        File.stub(:directory?).with('a') { true }
+
+        orderings = [
+          %w[ a/1.rb a/2.rb a/3.rb ],
+          %w[ a/2.rb a/1.rb a/3.rb ],
+          %w[ a/3.rb a/2.rb a/1.rb ]
+        ].map do |files|
+          Dir.should_receive(:[]).with(/^a/) { files }
+          yield
+          config.files_to_run
+        end.uniq
+
+        orderings.size.should eq(1)
+      end
+
+      context 'when the given directories match the pattern' do
+        it 'orders the files in a consistent ordering, regardless of the underlying OS ordering' do
+          test_files_to_run_ordering do
+            config.pattern = 'a/*.rb'
+            config.files_or_directories_to_run = 'a'
+          end
+        end
+      end
+
+      context 'when the pattern is given relative to the given directories' do
+        it 'orders the files in a consistent ordering, regardless of the underlying OS ordering' do
+          test_files_to_run_ordering do
+            config.pattern = '*.rb'
+            config.files_or_directories_to_run = 'a'
+          end
+        end
+      end
     end
 
     %w[pattern= filename_pattern=].each do |setter|

spec/rspec/core/rake_task_spec.rb

@@ -80,12 +80,39 @@ def spec_command
       end
     end
 
+    def test_files_to_run_ordering(pattern, task)
+      orderings = [
+        %w[ a/1.rb a/2.rb a/3.rb ],
+        %w[ a/2.rb a/1.rb a/3.rb ],
+        %w[ a/3.rb a/2.rb a/1.rb ]
+      ].map do |files|
+        FileList.should_receive(:[]).with(pattern) { files }
+        task.__send__(:files_to_run)
+      end.uniq
+
+      orderings.size.should eq(1)
+    end
+
     context "with SPEC env var set" do
       it "sets files to run" do
         with_env_vars 'SPEC' => 'path/to/file' do
           task.__send__(:files_to_run).should eq(["path/to/file"])
         end
       end
+
+      it "sets the files to run in a consistent order, regardless of the underlying FileList ordering" do
+        with_env_vars 'SPEC' => 'a/*.rb' do
+          test_files_to_run_ordering('a/*.rb', task)
+        end
+      end
+    end
+
+    it "sets the files to run in a consistent order, regardless of the underlying FileList ordering" do
+      task = RakeTask.new do |t|
+        t.pattern = 'a/*.rb'
+      end
+
+      test_files_to_run_ordering('a/*.rb', task)
     end
 
     context "with paths with quotes" do