WIP: Refactor metadata

benchmarks/delegate_v_defined.rb

@@ -0,0 +1,60 @@
+require 'benchmark'
+require 'delegate'
+
+class Original
+
+  def my_method
+    true
+  end
+
+end
+
+class Delegated < DelegateClass(Original)
+  def initialize
+    super(Original.new)
+  end
+end
+
+class Composed
+  def initialize
+    @original = Original.new
+  end
+
+  define_method(:my_method) { @original.my_method }
+end
+
+n = 100_000
+
+Benchmark.benchmark do |bm|
+  puts "#{n} times - ruby #{RUBY_VERSION}"
+
+  puts "[control] straight to obj"
+  bm.report do
+    n.times do
+      Original.new.my_method
+    end
+  end
+
+  puts "[delegate] DelegateClass to obj"
+  bm.report do
+    n.times do
+      Delegated.new.my_method
+    end
+  end
+
+  puts "[composed] passed to obj"
+  bm.report do
+    n.times do
+      Composed.new.my_method
+    end
+  end
+
+end
+
+# 100000 times - ruby 2.0.0
+# [control] straight to obj
+# 0.040000   0.000000   0.040000 (  0.038468)
+# [delegate] DelegateClass to obj
+# 0.230000   0.000000   0.230000 (  0.234356)
+# [composed] passed to obj
+# 0.070000   0.000000   0.070000 (  0.071021)

lib/rspec/core/example_group.rb

@@ -310,7 +310,7 @@ def self.set_it_up(*args)
         symbol_description = args.shift if args.first.is_a?(Symbol)
         args << build_metadata_hash_from(args)
         args.unshift(symbol_description) if symbol_description
-        @metadata = RSpec::Core::Metadata.new(superclass_metadata).process(*args)
+        @metadata = RSpec::Core::Metadata.new_for_example_group(superclass_metadata, *args)
         hooks.register_globals(self, RSpec.configuration.hooks)
         world.configure_group(self)
       end