sidekiq/testing - ability to run some configured server middleware chain on jobs recorded

[mikebaldry]

When using a client/server set of middleware that modify arguments in some way (supporting extra serialization for example), the client middleware runs and modifies the arguments, but the jobs stored by sidekiq/testing to assert against don't seem to have a way of running the server middleware against them.

This makes it awkward to test, because you're testing for the serialized args format, not what the Job would receive.

I'd be interested in implementing this somewhere in https://github.com/mperham/sidekiq/blob/main/lib/sidekiq/testing.rb

Would this be something you'd consider @mperham?

If so how would you suggest enabling this, as it would potentially be a breaking change in a test suite. Maybe Sidekiq::Testing.fake!(server_middleware: true) / Sidekiq::Testing.fake_options = { server_middleware: true } or something along those lines?

[mperham]

Are you looking for https://github.com/mperham/sidekiq/blob/b12300fc137e43b11bd127ec83b94d95852d6f32/lib/sidekiq/testing.rb#L53-L57 ?

[mperham]

Sidekiq::Testing.server_middleware.use MyMiddleware
Sidekiq::Testing.inline! do
  MyJob.perform_async
end

[mikebaldry]

Not quite, as I want to assert jobs queued and their arguments, not run them. So I'm using fake!

If I have a client middleware that makes all strings uppercase and a server middleware that makes them all lower case again:

MyJob.perform_later("cats", "dogs")

# test would fail
assert_equal MyJob.jobs.first["args"], ["cats", "dogs"]
# actual: ["CATS", "DOGS"]

I would expect that to pass - I'm testing the arguments I'm creating the job with, not the arguments as they're stored in redis

[mperham]

Your assumptions are wrong. Server-side middleware doesn’t execute until the job executes. It will be stored in upper case so that’s what you get from fake.

[mikebaldry]

Yes I know, I'm suggesting it should be possible to assert against what would be called on the job instead of what is stored in redis. I think that is a better experience and keeps the implementation of any middlewares from leaking in to unrelated tests

Would you consider a PR to add this?

[mperham]

I don't believe that's a good idea. fake allows you to see how the job will look in Redis. Use inline to mock a full round trip.

[mikebaldry]

I understand. It would be good to have some middleground. I'm not testing the underlying redis queue but I'm also not wanting to test the functionailty of my job 🤔