Send nearest backtrace entry on failsafe messages. @brianr.

lib/rollbar.rb

@@ -573,21 +573,7 @@ def do_write_payload(payload)
     end
 
     def send_failsafe(message, exception)
-      body = 'Failsafe from rollbar-gem: '
-      log_error "[Rollbar] Sending failsafe response due to #{message}."
-
-      if exception
-        begin
-          body += "#{exception.class.name}: #{message}"
-          log_error "[Rollbar] #{exception.class.name}: #{exception}"
-        rescue
-        end
-      else
-        begin
-          body += message.to_s
-        rescue
-        end
-      end
+      body = failsafe_body(message, exception)
 
       failsafe_data = {
         :level => 'error',
@@ -619,6 +605,33 @@ def send_failsafe(message, exception)
       failsafe_payload
     end
 
+    def failsafe_body(message, exception)
+      body = 'Failsafe from rollbar-gem. '
+      log_error "[Rollbar] Sending failsafe response due to #{message}."
+
+      if exception
+        begin
+          backtrace = exception.backtrace || []
+          nearest_frame = backtrace[0]
+
+          exception_info = exception.class.name
+          exception_info += " in #{nearest_frame}" if nearest_frame
+
+          body += "#{exception_info}: #{message}"
+
+          log_error "[Rollbar] #{body}"
+        rescue
+        end
+      else
+        begin
+          body += message.to_s
+        rescue
+        end
+      end
+
+      body
+    end
+
     def schedule_payload(payload)
       return if payload.nil?
 

spec/rollbar_spec.rb

@@ -1564,14 +1564,14 @@ def backtrace
   context "send_failsafe" do
     let(:exception) { StandardError.new }
 
-    it "should not crash when given a message and exception" do
+    it "doesn't crash when given a message and exception" do
       sent_payload = notifier.send(:send_failsafe, "test failsafe", exception)
 
       expected_message = 'Failsafe from rollbar-gem: StandardError: test failsafe'
       expect(sent_payload['data'][:body][:message][:body]).to be_eql(expected_message)
     end
 
-    it "should not crash when given all nils" do
+    it "doesn't crash when given all nils" do
       notifier.send(:send_failsafe, nil, nil)
     end
 
@@ -1583,6 +1583,19 @@ def backtrace
         expect(sent_payload['data'][:body][:message][:body]).to be_eql(expected_message)
       end
     end
+
+    context 'if the exception has a backtrace' do
+      let(:backtrace) { ['func3', 'func2', 'func1'] }
+
+      before { exception.set_backtrace(backtrace) }
+
+      it 'adds the nearest frame to the message' do
+        sent_payload = notifier.send(:send_failsafe, "test failsafe", exception)
+
+        expected_message = 'Failsafe from rollbar-gem: StandardError in func3: test failsafe'
+        expect(sent_payload['data'][:body][:message][:body]).to be_eql(expected_message)
+      end
+    end
   end
 
   context 'when reporting internal error with nil context' do