Fix inclusion order of RSpec::Matchers in Test::Unit and MiniTest.

Due to a bug in ruby 1.9, RSpec::Matchers must be included in the superclass (MiniTest::Unit::TestCase) before it is included in a subclass (Test::Unit::TestCase) or we may get infinite recursion and a SystemStackError from our `super` call in our method_missing hook.  See this gist for more info about the ruby 1.9 bug:

https://gist.github.com/845896

Closes #67.

lib/rspec/matchers.rb

@@ -155,13 +155,18 @@ module RSpec
   #   end
   #
   module Matchers
-    # Include Matchers for other test frameworks
-    if defined?(Test::Unit::TestCase)
-      Test::Unit::TestCase.send(:include, self)
-    end
+    # Include Matchers for other test frameworks.
+    # Note that MiniTest _must_ come before TU because on ruby 1.9,
+    # T::U::TC is a subclass of MT::U::TC and a 1.9 bug can lead
+    # to infinite recursion from the `super` call in our method_missing
+    # hook.  See this gist for more info:
+    #   https://gist.github.com/845896
     if defined?(MiniTest::Unit::TestCase)
       MiniTest::Unit::TestCase.send(:include, self)
     end
+    if defined?(Test::Unit::TestCase)
+      Test::Unit::TestCase.send(:include, self)
+    end
   end
 end
 

spec/rspec/matchers/be_spec.rb

@@ -1,10 +1,6 @@
 require 'spec_helper'
 
 describe "should be_predicate" do  
-  it "allows other undefined methods to raise errors as normal" do
-    expect { some_undefined_method }.to raise_error(NameError)
-  end
-
   it "passes when actual returns true for :predicate?" do
     actual = stub("actual", :happy? => true)
     actual.should be_happy

spec/rspec/matchers/matchers_spec.rb

@@ -1,19 +1,5 @@
 require 'spec_helper'
 
-module Test
-  module Unit
-    class TestCase
-    end
-  end
-end
-
-module MiniTest
-  module Unit
-    class TestCase
-    end
-  end
-end
-
 module RSpec
   describe Matchers do
 
@@ -25,21 +11,15 @@ module RSpec
     end
 
     context "once required" do
-
-      before(:all) do
-        path = File.expand_path("../../../../#{path}", __FILE__)
-        load File.join(path, 'lib/rspec/matchers.rb')
-      end
-
       it "includes itself in Test::Unit::TestCase" do
         test_unit_case = Test::Unit::TestCase.new
         sample_matchers.each do |sample_matcher|
             test_unit_case.should respond_to(sample_matcher)
         end
       end
 
-      it "includes itself in MiniTest::Unit::TestCase" do
-        minitest_case = MiniTest::Unit::TestCase.new
+      it "includes itself in MiniTest::Unit::TestCase", :if => defined?(MiniTest) do
+        minitest_case = MiniTest::Unit::TestCase.new(nil)
         sample_matchers.each do |sample_matcher|
             minitest_case.should respond_to(sample_matcher)
         end

spec/rspec/matchers/method_missing_spec.rb

@@ -0,0 +1,23 @@
+require 'spec_helper'
+
+shared_examples_for "a well-behaved method_missing hook" do
+  it "raises a NoMethodError (and not SystemStackError) for an undefined method" do
+    expect { subject.some_undefined_method }.to raise_error(NoMethodError)
+  end
+end
+
+describe "RSpec::Matchers method_missing hook" do
+  subject { self }
+  it_behaves_like "a well-behaved method_missing hook"
+
+  context 'when invoked in a Test::Unit::TestCase' do
+    subject { Test::Unit::TestCase.new }
+    it_behaves_like "a well-behaved method_missing hook"
+  end
+
+  context 'when invoked in a MiniTest::Unit::TestCase', :if => defined?(MiniTest) do
+    subject { MiniTest::Unit::TestCase.new(nil) }
+    it_behaves_like "a well-behaved method_missing hook"
+  end
+end
+

spec/spec_helper.rb

@@ -7,6 +7,14 @@ def add_to_load_path(path, prepend=false)
   end
 end
 
+require 'test/unit'
+
+# Make it easy to instantiate test cases for our specs.
+# Test::Unit::TestCase#initialize is picky about what arguments it expects.
+class Test::Unit::TestCase
+  def initialize; end
+end
+
 add_to_load_path("rspec-expectations", :prepend)
 add_to_load_path("rspec-core")
 add_to_load_path("rspec-mocks")