Make assert_enqueued_with and assert_performed_with returns the matched job

[byroot]

Sometimes job properties can't be asserted with pure equality. It might be because part of it is time sensitive and you need an assert_delta equivalent, or it might contain part of randomness.

Or it might even be that you only want to assert one of the passed arguments.

This PR makes assert_enqueued_with and assert_performed_with returns the matched job if any.

Example:

job = assert_enqueued_with(job: SomeJob) do
  some_business_logic
end

assert_in_delta 5.minutes.from_now, job.scheduled_at, 1
assert_equal 5, job.arguments.second

I know an assertion method returning a meaningful value might seems weird, but there is precedent for this. For example if you want to assert an exception message, the way do to with minitest is:

error = assert_raises TypeError do
  '1' + 2
end
assert_equal 'no implicit conversion of Fixnum into String', error.message

@rafaelfranca thoughts?

cc @etiennebarrie

[etiennebarrie]

Especially when you compare with the equivalent with serialized arguments:

assert_enqueued_with(job: SomeJob, args: [user]) do
  some_business_logic
end

vs.

job = enqueued_jobs.first
assert_equal SomeJob, job[:job]
assert_equal ActiveJob::Arguments.serialize([user]), job[:args]
assert_in_delta 5.minutes.from_now.to_i, job[:at], 1

Note the need to serialize :at with to_i and the call to ActiveJob::Arguments.serialize

[rafaelfranca]

LGTM, could you add a CHANGELOG entry?

[byroot]

Changelog entry added, thanks!