As each file is required, push it onto requires

lib/rspec/core/configuration.rb

@@ -1604,8 +1604,10 @@ def configure_example(example, example_hooks)
       def requires=(paths)
         directories = ['lib', default_path].select { |p| File.directory? p }
         RSpec::Core::RubyProject.add_to_load_path(*directories)
-        paths.each { |path| load_file_handling_errors(:require, path) }
-        @requires += paths
+        paths.each { |path|
+          load_file_handling_errors(:require, path)
+          @requires << path
+        }
       end
 
       # @private

spec/rspec/core/configuration_spec.rb

@@ -237,6 +237,16 @@ def absolute_path_to(dir)
         expect(config.requires).to eq ['a/path']
       end
 
+      it 'stores required paths "per file"' do
+        allow(config).to receive(:require).with('a/path')
+        expect(config).to receive(:require).with('another/path') do
+          expect(config.requires).to eq ['a/path']
+        end
+
+        config.requires = ['a/path', 'another/path']
+        expect(config.requires).to eq ['a/path', 'another/path']
+      end
+
       context "when `default_path` refers to a file rather than a directory" do
         it 'does not add it to the load path' do
           config.default_path = 'Rakefile'