NoMethodError in transaction_set_error when transaction is nil (SolidQueue)

[afthabvp]

Describe the bug

ActiveJobClassInstrumentation#transaction_set_error raises NoMethodError: undefined method 'set_error' for nil:NilClass when the transaction argument is nil. This happens in SolidQueue worker threads when Appsignal::Transaction.create fails and the job subsequently raises an exception.

To Reproduce

Steps to reproduce the behavior:

1. Use SolidQueue as the ActiveJob backend
2. A job fails in a SolidQueue worker thread where Appsignal::Transaction.create did not succeed
3. The rescue block in ActiveJobClassInstrumentation#execute calls transaction_set_error(nil, exception)
4. transaction_set_error calls nil.set_error(exception) → NoMethodError

Error

SolidQueue-1.3.2 Error in thread (0.0ms) error: "NoMethodError undefined method `set_error' for nil:NilClass"

Traceback points to lib/appsignal/hooks/active_job.rb:122.

Root cause

In lib/appsignal/hooks/active_job.rb:

def transaction_set_error(transaction, exception)
  return unless Appsignal.config[:activejob_report_errors] == "all"
  transaction.set_error(exception)  # ← no nil guard
end

The method checks the config but does not check if transaction is nil before calling .set_error.

Suggested fix

def transaction_set_error(transaction, exception)
  return unless transaction
  return unless Appsignal.config[:activejob_report_errors] == "all"

  transaction.set_error(exception)
end

Environment
Ruby: 3.2.4
Rails: 7.1.1
appsignal: 4.8.3 (also reproducible on 3.7.5)
solid_queue: 1.3.2

[unflxw]

Hi @afthabvp, thank you for reporting this!

Could you provide a reproduction case? Specifically I'm unsure as to what causes the precondition to step 2 in your reproduction steps, where "Appsignal::Transaction.create [does] not succeed"

The full traceback might also be useful.