Ensure the expected example count is reported accurately.

lib/rspec/core/runner.rb

@@ -105,7 +105,7 @@ def setup(err, out)
       #   or the configured failure exit code (1 by default) if specs
       #   failed.
       def run_specs(example_groups)
-        @configuration.reporter.report(@world.example_count) do |reporter|
+        @configuration.reporter.report(@world.example_count(example_groups)) do |reporter|
           begin
             hook_context = SuiteHookContext.new
             @configuration.hooks.run(:before, :suite, hook_context)

lib/rspec/core/world.rb

@@ -88,8 +88,8 @@ def configure_group(group)
       # @api private
       #
       # Get count of examples to be run
-      def example_count
-        FlatMap.flat_map(example_groups) {|g| g.descendants}.
+      def example_count(groups=example_groups)
+        FlatMap.flat_map(groups) {|g| g.descendants}.
           inject(0) {|sum, g| sum + g.filtered_examples.size}
       end
 

spec/rspec/core/runner_spec.rb

@@ -202,6 +202,43 @@ def run_specs
           expect(order).to eq([:start_set_1, :group_1, :start_set_2, :group_2])
         end
 
+        it 'reports the expected example count accurately, even when subclasses filter example groups' do
+          RSpec.describe("group 1") do
+            example("1") { }
+
+            context "nested" do
+              4.times { example { } }
+            end
+          end
+
+          RSpec.describe("group 2") do
+            example("2") { }
+            example("3") { }
+
+            context "nested" do
+              4.times { example { } }
+            end
+          end
+
+          subclass = Class.new(Runner) do
+            define_method :run_specs do |example_groups|
+              super(example_groups.select { |g| g.description == 'group 2' })
+            end
+          end
+
+          my_formatter = instance_double(Formatters::BaseFormatter).as_null_object
+          config.output_stream = out
+          config.deprecation_stream = err
+          config.reporter.register_listener(my_formatter, :start)
+
+          allow(config).to receive(:load_spec_files)
+          subclass.new(ConfigurationOptions.new([]), config, world).run(err, out)
+
+          expect(my_formatter).to have_received(:start) do |notification|
+            expect(notification.count).to eq(6)
+          end
+        end
+
         context "running files" do
           include_context "spec files"