lazily instantiate profiler

Author: JonRowe

lib/rspec/core/formatters.rb

@@ -121,7 +121,11 @@ def setup_default(output_stream, deprecation_stream)
         add DeprecationFormatter, deprecation_stream, output_stream
       end
 
-      return unless RSpec.configuration.profile_examples? && !existing_formatter_implements?(:dump_profile)
+      return unless RSpec.configuration.profile_examples?
+
+      @reporter.setup_profiler
+
+      return if existing_formatter_implements?(:dump_profile)
 
       add RSpec::Core::Formatters::ProfileFormatter, output_stream
     end

lib/rspec/core/reporter.rb

@@ -18,8 +18,6 @@ def initialize(configuration)
       @failed_examples = []
       @pending_examples = []
       @duration = @start = @load_time = nil
-      @profiler = Profiler.new
-      register_listener @profiler, *Profiler::NOTIFICATIONS
     end
 
     # @private
@@ -30,6 +28,13 @@ def reset
       @examples = []
       @failed_examples = []
       @pending_examples = []
+      @profiler = Profiler.new if defined?(@profiler)
+    end
+
+    # @private
+    def setup_profiler
+      @profiler = Profiler.new
+      register_listener @profiler, *Profiler::NOTIFICATIONS
     end
 
     # Registers a listener to a list of notifications. The reporter will send

spec/rspec/core/formatters_spec.rb

@@ -140,6 +140,7 @@ module RSpec::Core::Formatters
       context "without an existing profile formatter" do
         it "will add the profile formatter" do
           allow(reporter).to receive(:registered_listeners).with(:dump_profile) { [] }
+          expect(reporter).to receive(:setup_profiler)
           setup_default
           expect(loader.formatters.last).to be_a ::RSpec::Core::Formatters::ProfileFormatter
         end
@@ -148,6 +149,7 @@ module RSpec::Core::Formatters
       context "when a formatter that implement #dump_profile is added" do
         it "wont add the profile formatter" do
           allow(reporter).to receive(:registered_listeners).with(:dump_profile) { [:json] }
+          expect(reporter).to receive(:setup_profiler)
           setup_default
           expect(
             loader.formatters.map(&:class)

spec/rspec/core/reporter_spec.rb

@@ -25,6 +25,7 @@ module RSpec::Core
       it "dumps the failure summary after the profile and deprecation summary so failures don't scroll off the screen and get missed" do
         config.profile_examples = 10
         formatter = instance_double("RSpec::Core::Formatter::ProgressFormatter")
+        reporter.setup_profiler
         reporter.register_listener(formatter, :dump_summary, :dump_profile, :deprecation_summary)
 
         expect(formatter).to receive(:deprecation_summary).ordered

spec/support/formatter_support.rb

@@ -187,6 +187,7 @@ def setup_reporter(*streams)
 
   def setup_profiler
     config.profile_examples = true
+    reporter.setup_profiler
   end
 
   def formatter_output