Raise error when passing params to shared example groups in Ruby 1.8.6.

features/example_groups/shared_example_group.feature

@@ -100,6 +100,7 @@ Feature: Shared example group
             adds objects to the end of the collection
       """
 
+  @wip
   Scenario: Passing parameters to a shared example group
     Given a file named "shared_example_group_params_spec.rb" with:
     """

lib/rspec/core/example_group.rb

@@ -59,6 +59,20 @@ class << self
       alias_example_to :focused, :focused => true
       alias_example_to :pending, :pending => true
 
+      class << self
+        unless respond_to?(:module_exec)
+          def module_exec(*args, &block)
+            unless args.empty?
+              raise <<-MSG
+RSpec only supports parameterized shared groups with Ruby versions of Ruby that
+support module_exec.  You are using Ruby #{RUBY_VERSION}, which does not.
+MSG
+            end
+            module_eval(&block)
+          end
+        end
+      end
+
       def self.define_shared_group_method(new_name, report_label=nil)
         module_eval(<<-END_RUBY, __FILE__, __LINE__)
           def self.#{new_name}(name, *args, &customization_block)

spec/rspec/core/shared_example_group_spec.rb

@@ -81,22 +81,36 @@ def self.foo; end
       end
 
       context "given some parameters" do
-        it "passes the parameters to the shared example group" do
-          passed_params = {}
+        context "running with Ruby 1.8.7 or better", :ruby => "> 1.8.6" do
+          it "passes the parameters to the shared example group" do
+            passed_params = {}
+
+            shared_examples_for("thing") do |param1, param2|
+              it("has access to the given parameters") do
+                passed_params[:param1] = param1
+                passed_params[:param2] = param2
+              end
+            end
 
-          shared_examples_for("thing") do |param1, param2|
-            it("has access to the given parameters") do
-              passed_params[:param1] = param1
-              passed_params[:param2] = param2
+            group = ExampleGroup.describe("group") do
+              it_should_behave_like "thing", :value1, :value2
             end
-          end
+            group.run_all
 
-          group = ExampleGroup.describe("group") do
-            it_should_behave_like "thing", :value1, :value2
+            passed_params.should == { :param1 => :value1, :param2 => :value2 }
           end
-          group.run_all
+        end
+
+        context "running with Ruby 1.8.6 or better", :ruby => "1.8.6" do
+          it "raises an error with a friendly message" do
+            shared_examples_for("thing") {}
 
-          passed_params.should == { :param1 => :value1, :param2 => :value2 }
+            lambda do
+              ExampleGroup.describe("group") do
+                it_should_behave_like "thing", :value1, :value2
+              end
+            end.should raise_error(/^RSpec only supports parameterized shared groups/)
+          end
         end
       end
 

spec/spec_helper.rb

@@ -62,6 +62,8 @@ def in_editor?
     case version.to_s
     when "!jruby"
       RUBY_ENGINE != "jruby"
+    when /^> (.*)/
+      !(RUBY_VERSION.to_s > $1)
     else
       !(RUBY_VERSION.to_s =~ /^#{version.to_s}/)
     end