Fix failure screenshots on Rails 7.1

lib/rspec/rails/example/system_example_group.rb

@@ -44,6 +44,52 @@ def method_name
         ].join("_").tr(CHARS_TO_TRANSLATE.join, "_").byteslice(0...200).scrub("") + "_#{rand(1000)}"
       end
 
+      if ::Rails::VERSION::STRING.to_f >= 7.1
+        # @private
+        # Allows failure screenshot to work whilst not exposing metadata
+        class SuppressRailsScreenshotMetadata
+          def initialize
+            @example_data = {}
+          end
+
+          def [](key)
+            if @example_data.key?(key)
+              @example_data[key]
+            else
+              raise_wrong_scope_error
+            end
+          end
+
+          def []=(key, value)
+            if key == :failure_screenshot_path
+              @example_data[key] = value
+            else
+              raise_wrong_scope_error
+            end
+          end
+
+          def method_missing(_name, *_args, &_block)
+            raise_wrong_scope_error
+          end
+
+          private
+
+          def raise_wrong_scope_error
+            raise RSpec::Core::ExampleGroup::WrongScopeError,
+                  "`metadata` is not available from within an example " \
+                  "(e.g. an `it` block) or from constructs that run in the " \
+                  "scope of an example (e.g. `before`, `let`, etc). It is " \
+                  "only available on an example group (e.g. a `describe` or "\
+                  "`context` block)"
+          end
+        end
+
+        # @private
+        def metadata
+          @metadata ||= SuppressRailsScreenshotMetadata.new
+        end
+      end
+
       # Delegates to `Rails.application`.
       def app
         ::Rails.application

spec/rspec/rails/example/system_example_group_spec.rb

@@ -92,6 +92,53 @@ def take_screenshot
       end
     end
 
+    describe '#take_screenshot', if: ::Rails::VERSION::STRING.to_f >= 7.1 do
+      it 'handles Rails calling metadata' do
+        allow(Capybara::Session).to receive(:instance_created?).and_return(true)
+        group = RSpec::Core::ExampleGroup.describe do
+          include SystemExampleGroup
+
+          before do
+            driven_by(:selenium)
+          end
+
+          def page
+            instance_double(Capybara::Session, save_screenshot: nil)
+          end
+        end
+        example = group.it('fails') { raise }
+        group.run
+
+        expect(example.metadata[:execution_result].exception).to be_a RuntimeError
+      end
+    end
+
+    describe '#metadata', if: ::Rails::VERSION::STRING.to_f >= 7.1 do
+      let(:group) do
+        RSpec::Core::ExampleGroup.describe do
+          include SystemExampleGroup
+        end
+      end
+
+      it 'fakes out the rails expected method' do
+        example = group.it('does nothing') {
+          metadata[:failure_screenshot_path] = :value
+          expect(metadata[:failure_screenshot_path]).to eq(:value)
+        }
+        group.run
+        expect(example.execution_result.status).to eq :passed
+      end
+
+      it 'still raises correctly if you use it for something else' do
+        examples = []
+        examples << group.it('fails nothing') { metadata[:other] = :value }
+        examples << group.it('fails nothing') { metadata[:other] }
+        examples << group.it('fails nothing') { metadata.key?(:any) }
+        group.run
+        expect(examples.map(&:execution_result)).to all have_attributes status: :failed
+      end
+    end
+
     describe "hook order" do
       it 'calls Capybara.reset_sessions (TestUnit after_teardown) after any after hooks' do
         calls_in_order = []