Update lograge/patcher.rb so that the correct logger is checked

lib/datadog/tracing/contrib/lograge/patcher.rb

@@ -20,10 +20,12 @@ def target_version
 
           # patch applies our patch
           def patch
+            # First check Lograge logger directly for when keep_original_rails_log option is used
+            used_logger = ::Lograge.logger || ::Lograge::LogSubscribers::ActionController.logger
+
             # ActiveSupport::TaggedLogging is the default Rails logger since Rails 5
             if defined?(::ActiveSupport::TaggedLogging::Formatter) &&
-                ::Lograge::LogSubscribers::ActionController
-                    .logger&.formatter.is_a?(::ActiveSupport::TaggedLogging::Formatter)
+                used_logger&.formatter.is_a?(::ActiveSupport::TaggedLogging::Formatter)
               Datadog.logger.warn(
                 'Lograge and ActiveSupport::TaggedLogging (the default Rails log formatter) are not compatible: ' \
                   'Lograge does not account for Rails log tags, creating polluted logs and breaking log formatting. ' \

spec/datadog/tracing/contrib/lograge/patcher_spec.rb

@@ -21,15 +21,43 @@
       end
     end
 
-    context 'with Rails tagged logging' do
+    context 'with tagged logging for the Lograge logger' do
+      before do
+        logger = ActiveSupport::TaggedLogging.new(Logger.new(File::NULL))
+        allow(::Lograge).to receive(:logger).and_return(logger)
+      end
+
       it 'logs an incompatibility error' do
+        expect(Datadog.logger).to receive(:warn).with(/ActiveSupport::TaggedLogging/)
+
+        described_class.patch
+      end
+    end
+
+    context 'with tagged logging for the Rails logger' do
+      before do
         logger = ActiveSupport::TaggedLogging.new(Logger.new(File::NULL))
         stub_const('Lograge::LogSubscribers::ActionController', double('controller', logger: logger))
+      end
 
+      it 'logs an incompatibility error' do
         expect(Datadog.logger).to receive(:warn).with(/ActiveSupport::TaggedLogging/)
 
         described_class.patch
       end
+
+      context "when the Lograge logger does not use tagged logging" do
+        before do
+          logger = ActiveSupport::Logger.new(File::NULL)
+          allow(::Lograge).to receive(:logger).and_return(logger)
+        end
+
+        it 'does not log incompatibility error' do
+          expect(Datadog.logger).to_not receive(:warn)
+
+          described_class.patch
+        end
+      end
     end
   end
 end