Report activejob errors only when the job is discarded

[tombruijn]

In PR #1040 the activejob_report_errors config option was added. This only supports "all" (the orignal behavior to report all errors) and "none" (to disable error reporting).

It should also have the option to "discard", to only report errors if the job is discarded and no longer will be retried.

We can listen to the after_discard callback on the job, but I didn't manage to make it work yet, because in the test suite the job gets instantly retried, within the execute method we instrument, so we can't test if it crates one transaction without an error and one transaction with an error.

WIP branch: https://github.com/appsignal/appsignal-ruby/tree/active-job-error-discard

To do

• Implement option in Ruby gem
• Update activejob_report_errors docs to include discard

[backlog-helper]

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[tombruijn]

This was released in Ruby gem 3.7.3. See also the docs for this https://docs.appsignal.com/ruby/integrations/active-job.html (once deployed in a min or two).