Load only files with failures when using rspec --only-failures.

Loading ALL spec files when only a handful have failures is inefficient
and could make the run take significantly longer. Note that we only do
this if no file or directory arg is passed to `rspec`. If the user
passes anything, we load what they tell us to load.

Author: myronmarston

features/command_line/only_failures.feature

@@ -55,11 +55,22 @@ Feature: Only Failures
         end
       end
       """
-    And I have run `rspec` once, resulting in "7 examples, 3 failures"
+    And a file named "spec/passing_spec.rb" with:
+      """ruby
+      puts "Loading passing_spec.rb"
+
+      RSpec.describe "A passing spec" do
+        it "passes" do
+          expect(1).to eq(1)
+        end
+      end
+      """
+    And I have run `rspec` once, resulting in "8 examples, 3 failures"
 
-  Scenario: Use just `--only-failures`
+  Scenario: Running `rspec --only-failures` loads only spec files with failures and runs only the failures
     When I run `rspec --only-failures`
-    Then the output should contain "3 examples, 3 failures"
+    Then the output from "rspec --only-failures" should contain "3 examples, 3 failures"
+     And the output from "rspec --only-failures" should not contain "Loading passing_spec.rb"
 
   Scenario: Combine `--only-failures` with a file name
     When I run `rspec spec/array_spec.rb --only-failures`
@@ -91,4 +102,3 @@ Feature: Only Failures
 
     When I run `rspec --next-failure`
     Then the output should contain "All examples were filtered out"
-

lib/rspec/core/configuration.rb

@@ -159,6 +159,11 @@ def deprecation_stream=(value)
       # `--only-failures` and `--next-failures` CLI options.
       add_setting :example_status_persistence_file_path
 
+      # @macro define_reader
+      # Indicates if the `--only-failures` (or `--next-failure`) flag is being used.
+      define_reader :only_failures
+      alias_method :only_failures?, :only_failures
+
       # @macro add_setting
       # Clean up and exit after the first failure (default: `false`).
       add_setting :fail_fast
@@ -310,6 +315,7 @@ def initialize
         @after_suite_hooks  = []
 
         @mock_framework = nil
+        @files_or_directories_to_run_defaulted = false
         @files_or_directories_to_run = []
         @loaded_spec_files = Set.new
         @color = false
@@ -797,15 +803,29 @@ def profile_examples
       # @private
       def files_or_directories_to_run=(*files)
         files = files.flatten
-        files << default_path if (command == 'rspec' || Runner.running_in_drb?) && default_path && files.empty?
+
+        if (command == 'rspec' || Runner.running_in_drb?) && default_path && files.empty?
+          @files_or_directories_to_run_defaulted = true
+          files << default_path
+        else
+          @files_or_directories_to_run_defaulted = false
+        end
+
         @files_or_directories_to_run = files
         @files_to_run = nil
       end
 
       # The spec files RSpec will run.
       # @return [Array] specified files about to run
       def files_to_run
-        @files_to_run ||= get_files_to_run(@files_or_directories_to_run)
+        @files_to_run ||= begin
+          if @files_or_directories_to_run_defaulted && only_failures?
+            files_with_failures = RSpec.world.spec_files_with_failures.to_a
+            @files_or_directories_to_run = files_with_failures if files_with_failures.any?
+          end
+
+          get_files_to_run(@files_or_directories_to_run)
+        end
       end
 
       # Creates a method that delegates to `example` including the submitted

lib/rspec/core/configuration_options.rb

@@ -81,7 +81,7 @@ def order(keys)
 
         # `files_or_directories_to_run` uses `default_path` so it must be
         # set before it.
-        :default_path,
+        :default_path, :only_failures,
 
         # These must be set before `requires` to support checking
         # `config.files_to_run` from within `spec_helper.rb` when a

lib/rspec/core/option_parser.rb

@@ -155,12 +155,12 @@ def parser(options)
 FILTERING
 
         parser.on('--only-failures', "Filter to just the examples that failed the last time they ran.") do
-          add_tag_filter(options, :inclusion_filter, :last_run_status, 'failed')
+          configure_only_failures(options)
         end
 
         parser.on("--next-failure", "Apply `--only-failures` and abort after one failure.",
                   "  (Equivalent to `--only-failures --fail-fast --order defined`)") do
-          add_tag_filter(options, :inclusion_filter, :last_run_status, 'failed')
+          configure_only_failures(options)
           set_fail_fast(options, true)
           set_order(options, "defined")
         end
@@ -252,5 +252,10 @@ def set_fail_fast(options, value)
     def set_order(options, value)
       options[:order] = value
     end
+
+    def configure_only_failures(options)
+      options[:only_failures] = true
+      add_tag_filter(options, :inclusion_filter, :last_run_status, 'failed')
+    end
   end
 end

lib/rspec/core/world.rb

@@ -121,6 +121,18 @@ def last_run_statuses
           end
       end
 
+      # @private
+      def spec_files_with_failures
+        @spec_files_with_failures ||=
+          last_run_statuses.inject(Set.new) do |files, (id, status)|
+            files << id.split(Configuration::ON_SQUARE_BRACKETS).first if status == FAILED_STATUS
+            files
+          end.to_a
+      end
+
+      # @private
+      FAILED_STATUS = "failed".freeze
+
       # @api private
       #
       # Notify reporter of filters.

spec/rspec/core/configuration_options_spec.rb

@@ -106,6 +106,13 @@
       opts.configure(config)
     end
 
+    it 'configures `only_failures` before `files_or_directories_to_run` since it affects loaded files' do
+      opts = config_options_object(*%w[ --only-failures ])
+      expect(config).to receive(:force).with(:only_failures => true).ordered
+      expect(config).to receive(:files_or_directories_to_run=).ordered
+      opts.configure(config)
+    end
+
     { "pattern" => :pattern, "exclude-pattern" => :exclude_pattern }.each do |flag, attr|
       it "sets #{attr} before `requires` so users can check `files_to_run` in a `spec_helper` loaded by `--require`" do
         opts = config_options_object(*%W[--require spec_helpe --#{flag} **/*.spec])
@@ -168,6 +175,18 @@
         opts.configure(config)
       end
     end
+
+    %w[ --only-failures --next-failure ].each do |option|
+      describe option do
+        it "changes `config.only_failures?` to true" do
+          opts = config_options_object(option)
+
+          expect {
+            opts.configure(config)
+          }.to change(config, :only_failures?).from(a_falsey_value).to(true)
+        end
+      end
+    end
   end
 
   describe "-c, --color, and --colour" do

spec/rspec/core/configuration_spec.rb

@@ -488,6 +488,52 @@ def stub_expectation_adapters
         end
       end
 
+      context "when only_failures is set" do
+        around { |ex| Dir.chdir("spec/rspec/core", &ex) }
+        let(:default_path) { "resources" }
+        let(:files_with_failures) { ["resources/a_spec.rb"] }
+        let(:files_loaded_via_default_path) do
+          config = Configuration.new
+          config.default_path = default_path
+          config.files_or_directories_to_run = []
+          config.files_to_run
+        end
+
+        before do
+          expect(files_loaded_via_default_path).not_to eq(files_with_failures)
+          config.default_path = default_path
+          allow(RSpec.world).to receive_messages(:spec_files_with_failures => files_with_failures)
+          config.force(:only_failures => true)
+        end
+
+        context "and no explicit paths have been set" do
+          it 'loads only the files that have failures' do
+            assign_files_or_directories_to_run
+            expect(config.files_to_run).to eq(files_with_failures)
+          end
+
+          it 'loads the default path if there are no files with failures' do
+            allow(RSpec.world).to receive_messages(:spec_files_with_failures => [])
+            assign_files_or_directories_to_run
+            expect(config.files_to_run).to eq(files_loaded_via_default_path)
+          end
+        end
+
+        context "and a path has been set" do
+          it "ignores the list of files with failures, loading the configured path instead" do
+            assign_files_or_directories_to_run "resources/acceptance"
+            expect(config.files_to_run).to contain_files("resources/acceptance/foo_spec.rb")
+          end
+        end
+
+        context "and the default path has been explicitly set" do
+          it "ignores the list of files with failures, loading the configured path instead" do
+            assign_files_or_directories_to_run default_path
+            expect(config.files_to_run).to eq(files_loaded_via_default_path)
+          end
+        end
+      end
+
       context "with default pattern" do
         it "loads files named _spec.rb" do
           assign_files_or_directories_to_run "spec/rspec/core/resources"

spec/rspec/core/option_parser_spec.rb

@@ -128,7 +128,7 @@ def generate_help_text
         tag = Parser.parse(%w[ --tag last_run_status:failed ])
         only_failures = Parser.parse(%w[ --only-failures ])
 
-        expect(only_failures).to eq(tag)
+        expect(only_failures).to include(tag)
       end
     end
 
@@ -137,7 +137,7 @@ def generate_help_text
         long_form = Parser.parse(%w[ --tag last_run_status:failed --fail-fast --order defined ])
         next_failure = Parser.parse(%w[ --next-failure ])
 
-        expect(next_failure).to eq(long_form)
+        expect(next_failure).to include(long_form)
       end
     end
 

spec/rspec/core/world_spec.rb

@@ -23,16 +23,20 @@ module RSpec::Core
       end
     end
 
+    def simulate_persisted_examples(*examples)
+      configuration.example_status_persistence_file_path = "examples.txt"
+      persister = class_double(ExampleStatusPersister).as_stubbed_const
+
+      allow(persister).to receive(:load_from).with("examples.txt").and_return(examples)
+    end
+
     describe "#last_run_statuses" do
       context "when `example_status_persistence_file_path` is configured" do
         it 'gets the last run statuses from the ExampleStatusPersister' do
-          configuration.example_status_persistence_file_path = "examples.txt"
-          persister = class_double(ExampleStatusPersister).as_stubbed_const
-
-          allow(persister).to receive(:load_from).with("examples.txt").and_return([
+          simulate_persisted_examples(
             { :example_id => "id_1", :status => "passed" },
             { :example_id => "id_2", :status => "failed" }
-          ])
+          )
 
           expect(world.last_run_statuses).to eq(
             'id_1' => 'passed', 'id_2' => 'failed'
@@ -56,6 +60,37 @@ module RSpec::Core
       end
     end
 
+    describe "#spec_files_with_failures" do
+      context "when `example_status_persistence_file_path` is configured" do
+        it 'returns a memoized array of unique spec files that contain failed exaples' do
+          simulate_persisted_examples(
+            { :example_id => "./spec_1.rb[1:1]", :status => "failed"  },
+            { :example_id => "./spec_1.rb[1:2]", :status => "failed"  },
+            { :example_id => "./spec_2.rb[1:2]", :status => "passed"  },
+            { :example_id => "./spec_3.rb[1:2]", :status => "pending" },
+            { :example_id => "./spec_4.rb[1:2]", :status => "unknown" },
+            { :example_id => "./spec_5.rb[1:2]", :status => "failed"  }
+          )
+
+          expect(world.spec_files_with_failures).to(
+            be_an(Array) &
+            be(world.spec_files_with_failures) &
+            contain_exactly("./spec_1.rb", "./spec_5.rb")
+          )
+        end
+      end
+
+      context "when `example_status_persistence_file_path1` is not configured" do
+        it "returns a memoized blank array" do
+          configuration.example_status_persistence_file_path = nil
+
+          expect(world.spec_files_with_failures).to(
+            eq([]) & be(world.spec_files_with_failures)
+          )
+        end
+      end
+    end
+
     describe "#all_examples" do
       it "contains all examples from all levels of nesting" do
         RSpec.describe do