[rails] support string errors in error reporter

CHANGELOG.md

@@ -5,6 +5,7 @@
 - Add `include_sentry_event` matcher for RSpec [#2424](https://github.com/getsentry/sentry-ruby/pull/2424)
 - Add support for Sentry Cache instrumentation, when using Rails.cache ([#2380](https://github.com/getsentry/sentry-ruby/pull/2380))
 - Add support for Queue Instrumentation for Sidekiq. [#2403](https://github.com/getsentry/sentry-ruby/pull/2403)
+- Add support for string errors in error reporter ([#2464](https://github.com/getsentry/sentry-ruby/pull/2464))
 - Reset trace_id and add root transaction for sidekiq-cron [#2446](https://github.com/getsentry/sentry-ruby/pull/2446)
 
     Note: MemoryStore and FileStore require Rails 8.0+

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

@@ -27,7 +27,16 @@
           hint.merge!(context.delete(:hint))
         end
 
-        Sentry::Rails.capture_exception(error, level: severity, contexts: { "rails.error" => context }, tags: tags, hint: hint)
+        options = { level: severity, contexts: { "rails.error" => context }, tags: tags, hint: hint }
+
+        case error
+        when String
+          Sentry::Rails.capture_message(error, **options)
+        when Exception
+          Sentry::Rails.capture_exception(error, **options)
+        else
+          raise ArgumentError, "Expected an Exception or a String, got: #{error.inspect}"
+        end
       end
     end
   end

sentry-rails/spec/sentry/rails_spec.rb

@@ -356,6 +356,25 @@ def capture_in_separate_process(exit_code:)
 
         expect(transport.events.count).to eq(0)
       end
+
+      it "captures string messages through error reporter" do
+        Rails.error.report("Test message", severity: :info, context: { foo: "bar" })
+
+        expect(transport.events.count).to eq(1)
+        event = transport.events.first
+
+        expect(event.message).to eq("Test message")
+        expect(event.level).to eq(:info)
+        expect(event.contexts).to include({ "rails.error" => { foo: "bar" } })
+        expect(event.tags).to include({ handled: true })
+      end
+
+      it "crashes if the message is not a string or an exception" do
+        # Subscriber crashes are handled and logged as fatal, so this doesn't raise here
+        Rails.error.report(312, severity: :info, context: { foo: "bar" })
+
+        expect(transport.events.count).to eq(0)
+      end
     end
   end
 end