Always limit loaded files when --only-failures is used.

Before, we only did so when no file or directory arg was passed
to `rspec`, but it's better to take the intersection of files
matching the provided args and files with failures.

Author: myronmarston

lib/rspec/core/configuration.rb

@@ -327,7 +327,6 @@ 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
@@ -821,10 +820,7 @@ def files_or_directories_to_run=(*files)
         files = files.flatten
 
         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
@@ -834,14 +830,7 @@ def files_or_directories_to_run=(*files)
       # The spec files RSpec will run.
       # @return [Array] specified files about to run
       def files_to_run
-        @files_to_run ||= begin
-          if @files_or_directories_to_run_defaulted && only_failures?
-            files_with_failures = 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
+        @files_to_run ||= get_files_to_run(@files_or_directories_to_run)
       end
 
       # @private
@@ -1624,10 +1613,15 @@ def run_hooks_with(hooks, hook_context)
       end
 
       def get_files_to_run(paths)
-        FlatMap.flat_map(paths_to_check(paths)) do |path|
+        files = FlatMap.flat_map(paths_to_check(paths)) do |path|
           path = path.gsub(File::ALT_SEPARATOR, File::SEPARATOR) if File::ALT_SEPARATOR
           File.directory?(path) ? gather_directories(path) : extract_location(path)
         end.sort.uniq
+
+        return files unless only_failures?
+        relative_files = files.map { |f| Metadata.relative_path(File.expand_path f) }
+        with_failures = (relative_files & spec_files_with_failures.to_a)
+        with_failures.empty? ? files : with_failures
       end
 
       def paths_to_check(paths)

spec/rspec/core/configuration/only_failures_support_spec.rb

@@ -132,9 +132,14 @@ def allows_value_to_change_when_updated
     end
 
     describe "#files_to_run, when `only_failures` is set" do
-      around { |ex| Dir.chdir("spec/rspec/core", &ex) }
+      around do |ex|
+        handle_current_dir_change do
+          Dir.chdir("spec/rspec/core", &ex)
+        end
+      end
+
       let(:default_path) { "resources" }
-      let(:files_with_failures) { ["resources/a_spec.rb"] }
+      let(:files_with_failures) { ["./resources/a_spec.rb"] }
       let(:files_loaded_via_default_path) do
         configuration = Configuration.new
         configuration.default_path = default_path
@@ -167,16 +172,14 @@ def allows_value_to_change_when_updated
       end
 
       context "and a path has been set" do
-        it "ignores the list of files with failures, loading the configured path instead" do
-          config.files_or_directories_to_run = ["resources/acceptance"]
-          expect(config.files_to_run).to contain_files("resources/acceptance/foo_spec.rb")
+        it "loads the intersection of files matching the path and files with failures" do
+          config.files_or_directories_to_run = ["resources"]
+          expect(config.files_to_run).to eq(files_with_failures)
         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
-          config.files_or_directories_to_run = [default_path]
-          expect(config.files_to_run).to eq(files_loaded_via_default_path)
+        it "loads all files matching the path when there are no intersecting files" do
+          config.files_or_directories_to_run = ["resources/acceptance"]
+          expect(config.files_to_run).to contain_files("resources/acceptance/foo_spec.rb")
         end
       end
     end

spec/spec_helper.rb

@@ -53,10 +53,20 @@ def without_env_vars(*vars)
       ENV.replace(original)
     end
   end
+
+  def handle_current_dir_change
+    RSpec::Core::Metadata.instance_variable_set(:@relative_path_regex, nil)
+    yield
+  ensure
+    RSpec::Core::Metadata.instance_variable_set(:@relative_path_regex, nil)
+  end
 end
 
 RSpec.configure do |c|
   c.example_status_persistence_file_path = "./spec/examples.txt"
+  c.around(:example, :isolated_directory) do |ex|
+    handle_current_dir_change(&ex)
+  end
 
   # structural
   c.alias_it_behaves_like_to 'it_has_behavior'

spec/support/aruba_support.rb

@@ -17,16 +17,16 @@ def run_command(cmd)
 
     temp_stdout = StringIO.new
     temp_stderr = StringIO.new
-    RSpec::Core::Metadata.instance_variable_set(:@relative_path_regex, nil)
     cmd_parts = Shellwords.split(cmd)
 
-    in_current_dir do
-      RSpec::Core::Runner.run(cmd_parts, temp_stderr, temp_stdout)
+    handle_current_dir_change do
+      in_current_dir do
+        RSpec::Core::Runner.run(cmd_parts, temp_stderr, temp_stdout)
+      end
     end
   ensure
     RSpec.reset
     RSpec.configuration.color = true
-    RSpec::Core::Metadata.instance_variable_set(:@relative_path_regex, nil)
 
     # Ensure it gets cached with a proper value -- if we leave it set to nil,
     # and the next spec operates in a different dir, it could get set to an