fix(rails): set mechanism.handled based on error handling status (#2892)

Author: solnic

sentry-rails/lib/sentry/rails/error_subscriber.rb

@@ -27,6 +27,8 @@ def report(error, handled:, severity:, context:, source: nil)
           hint.merge!(context.delete(:hint))
         end
 
+        hint[:mechanism] ||= Sentry::Mechanism.new(type: Sentry::Rails.integration_name, handled: handled)
+
         Sentry::Rails.capture_exception(error, level: severity, contexts: { "rails.error" => context }, tags: tags, hint: hint)
       end
     end

sentry-rails/spec/sentry/rails/error_subscriber_spec.rb

@@ -71,6 +71,24 @@
       end
     end
 
+    context 'when handled: true' do
+      it 'sets mechanism.handled to true' do
+        expect(Sentry::Rails).to receive(:capture_exception) do |_, hint:, **_|
+          expect(hint[:mechanism].handled).to eq(true)
+        end
+        described_class.new.report(StandardError.new, handled: true, severity: :error, context: {})
+      end
+    end
+
+    context 'when handled: false' do
+      it 'sets mechanism.handled to false' do
+        expect(Sentry::Rails).to receive(:capture_exception) do |_, hint:, **_|
+          expect(hint[:mechanism].handled).to eq(false)
+        end
+        described_class.new.report(StandardError.new, handled: false, severity: :error, context: {})
+      end
+    end
+
     context 'when passed a context with hint key' do
       context 'when hint is a Hash' do
         it 'merges the hint into the event' do