Standardize on rspec-support’s thread local data hash.

lib/rspec/core.rb

@@ -119,20 +119,13 @@ def self.configure
   #     end
   #
   def self.current_example
-    thread_local_metadata[:current_example]
+    RSpec::Support.thread_local_data[:current_example]
   end
 
   # Set the current example being executed.
   # @api private
   def self.current_example=(example)
-    thread_local_metadata[:current_example] = example
-  end
-
-  # @private
-  # A single thread local variable so we don't excessively pollute that
-  # namespace.
-  def self.thread_local_metadata
-    Thread.current[:_rspec] ||= { :shared_example_group_inclusions => [] }
+    RSpec::Support.thread_local_data[:current_example] = example
   end
 
   # @private

lib/rspec/core/example_group.rb

@@ -231,7 +231,7 @@ def self.define_example_method(name, extra_options={})
       # @see DSL#describe
       def self.define_example_group_method(name, metadata={})
         idempotently_define_singleton_method(name) do |*args, &example_group_block|
-          thread_data = RSpec.thread_local_metadata
+          thread_data = RSpec::Support.thread_local_data
           top_level   = self == ExampleGroup
 
           if top_level
@@ -705,17 +705,22 @@ def description
 
       # @private
       def self.current_backtrace
-        RSpec.thread_local_metadata[:shared_example_group_inclusions].reverse
+        shared_example_group_inclusions.reverse
       end
 
       # @private
       def self.with_frame(name, location)
-        current_stack = RSpec.thread_local_metadata[:shared_example_group_inclusions]
+        current_stack = shared_example_group_inclusions
         current_stack << new(name, location)
         yield
       ensure
         current_stack.pop
       end
+
+      # @private
+      def self.shared_example_group_inclusions
+        RSpec::Support.thread_local_data[:shared_example_group_inclusions] ||= []
+      end
     end
   end
 

lib/rspec/core/metadata.rb

@@ -270,7 +270,7 @@ def self.backwards_compatibility_default_proc(&example_group_selector)
               # that take a metadata hash, and MetadataFilter sets this thread
               # local to silence the warning here since it would be so
               # confusing.
-              unless RSpec.thread_local_metadata[:silence_metadata_example_group_deprecations]
+              unless RSpec::Support.thread_local_data[:silence_metadata_example_group_deprecations]
                 RSpec.deprecate("The `:example_group` key in an example group's metadata hash",
                                 :replacement => "the example group's hash directly for the " \
                                 "computed keys and `:parent_example_group` to access the parent " \

lib/rspec/core/metadata_filter.rb

@@ -78,10 +78,10 @@ def filters_apply?(key, value, metadata)
         end
 
         def silence_metadata_example_group_deprecations
-          RSpec.thread_local_metadata[:silence_metadata_example_group_deprecations] = true
+          RSpec::Support.thread_local_data[:silence_metadata_example_group_deprecations] = true
           yield
         ensure
-          RSpec.thread_local_metadata.delete(:silence_metadata_example_group_deprecations)
+          RSpec::Support.thread_local_data.delete(:silence_metadata_example_group_deprecations)
         end
       end
     end

lib/rspec/core/shared_example_group.rb

@@ -80,7 +80,7 @@ module SharedExampleGroup
       # @see ExampleGroup.include_context
       def shared_examples(name, *args, &block)
         top_level = self == ExampleGroup
-        if top_level && RSpec.thread_local_metadata[:in_example_group]
+        if top_level && RSpec::Support.thread_local_data[:in_example_group]
           raise "Creating isolated shared examples from within a context is " \
                 "not allowed. Remove `RSpec.` prefix or move this to a " \
                 "top-level scope."

spec/rspec/core/example_group_spec.rb

@@ -1460,15 +1460,15 @@ def extract_execution_results(group)
         it "leaves RSpec's thread metadata unchanged" do
           expect {
             self.group.send(name, "named this")
-          }.to avoid_changing(RSpec, :thread_local_metadata)
+          }.to avoid_changing(RSpec::Support, :thread_local_data)
         end
 
         it "leaves RSpec's thread metadata unchanged, even when an error occurs during evaluation" do
           expect {
             self.group.send(name, "named this") do
               raise "boom"
             end
-          }.to raise_error("boom").and avoid_changing(RSpec, :thread_local_metadata)
+          }.to raise_error("boom").and avoid_changing(RSpec::Support, :thread_local_data)
         end
 
         it "passes parameters to the shared content" do
@@ -1637,7 +1637,7 @@ def foo; end
             shared_examples_for("stuff") { }
             it_should_behave_like "stuff"
           end
-        }.to avoid_changing(RSpec, :thread_local_metadata)
+        }.to avoid_changing(RSpec::Support, :thread_local_data)
       end
 
       it "leaves RSpec's thread metadata unchanged, even when an error occurs during evaluation" do
@@ -1648,7 +1648,7 @@ def foo; end
               raise "boom"
             end
           end
-        }.to raise_error("boom").and avoid_changing(RSpec, :thread_local_metadata)
+        }.to raise_error("boom").and avoid_changing(RSpec::Support, :thread_local_data)
       end
     end
 

spec/rspec/core_spec.rb

@@ -218,6 +218,14 @@
     end
   end
 
+  it 'uses only one thread local variable', :run_last do
+    # Trigger features that use thread locals...
+    aggregate_failures { }
+    RSpec.shared_examples_for("something") { }
+
+    expect(Thread.current.keys.map(&:to_s).grep(/rspec/i).count).to eq(1)
+  end
+
   describe "::Core.path_to_executable" do
     it 'returns the absolute location of the exe/rspec file' do
       expect(File.exist? RSpec::Core.path_to_executable).to be_truthy