Update minitest integration

Since the integration is dependent on minitest-rails, use its test class.
Did MiniTest::Spec::Decorator ever exist in this project?

draper.gemspec

@@ -23,5 +23,6 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'rake', '~> 0.9.2'
   s.add_development_dependency 'rspec', '~> 2.10'
   s.add_development_dependency 'yard'
+  s.add_development_dependency 'minitest-rails', '~> 0.2'
   s.add_development_dependency 'minitest', '~> 3.0' if RUBY_PLATFORM == "java"
 end

lib/draper.rb

@@ -13,4 +13,4 @@ require 'draper/railtie' if defined?(Rails)
 
 # Test Support
 require 'draper/test/rspec_integration'    if defined?(RSpec) and RSpec.respond_to?(:configure)
-require 'draper/test/minitest_integration' if defined?(MiniTest::Spec)
+require 'draper/test/minitest_integration' if defined?(MiniTest::Rails)

lib/draper/test/minitest_integration.rb

@@ -1,5 +1,7 @@
-require 'draper/test/view_context'
-
-MiniTest::Spec.register_spec_type(MiniTest::Spec::Decorator) do |desc|
-  desc.superclass == Draper::Base
+class MiniTest::Rails::ActiveSupport::TestCase
+  # Use AS::TestCase for the base class when describing a decorator
+  register_spec_type(self) do |desc|
+    desc < Draper::Base if desc.is_a?(Class)
+  end
+  register_spec_type(/Decorator( ?Test)?\z/i, self)
 end

spec/minitest-rails/spec_type_spec.rb

@@ -0,0 +1,63 @@
+require 'spec_helper'
+require 'minitest/rails/active_support'
+require 'draper/test/minitest_integration'
+
+describe "minitest-rails spec_type Lookup Integration" do
+  context "ProductDecorator" do
+    it "resolves constants" do
+      klass = MiniTest::Spec.spec_type(ProductDecorator)
+      klass.should == MiniTest::Rails::ActiveSupport::TestCase
+    end
+
+    it "resolves strings" do
+      klass = MiniTest::Spec.spec_type("ProductDecorator")
+      klass.should == MiniTest::Rails::ActiveSupport::TestCase
+    end
+  end
+
+  context "WidgetDecorator" do
+    it "resolves constants" do
+      klass = MiniTest::Spec.spec_type(WidgetDecorator)
+      klass.should == MiniTest::Rails::ActiveSupport::TestCase
+    end
+
+    it "resolves strings" do
+      klass = MiniTest::Spec.spec_type("WidgetDecorator")
+      klass.should == MiniTest::Rails::ActiveSupport::TestCase
+    end
+  end
+
+  context "decorator strings" do
+    it "resolves DoesNotExistDecorator" do
+      klass = MiniTest::Spec.spec_type("DoesNotExistDecorator")
+      klass.should == MiniTest::Rails::ActiveSupport::TestCase
+    end
+
+    it "resolves DoesNotExistDecoratorTest" do
+      klass = MiniTest::Spec.spec_type("DoesNotExistDecoratorTest")
+      klass.should == MiniTest::Rails::ActiveSupport::TestCase
+    end
+
+    it "resolves Does Not Exist Decorator" do
+      klass = MiniTest::Spec.spec_type("Does Not Exist Decorator")
+      klass.should == MiniTest::Rails::ActiveSupport::TestCase
+    end
+
+    it "resolves Does Not Exist Decorator Test" do
+      klass = MiniTest::Spec.spec_type("Does Not Exist Decorator Test")
+      klass.should == MiniTest::Rails::ActiveSupport::TestCase
+    end
+  end
+
+  context "non-decorators" do
+    it "doesn't resolve constants" do
+      klass = MiniTest::Spec.spec_type(Draper::HelperSupport)
+      klass.should == MiniTest::Spec
+    end
+
+    it "doesn't resolve strings" do
+      klass = MiniTest::Spec.spec_type("Nothing to see here...")
+      klass.should == MiniTest::Spec
+    end
+  end
+end