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Use `TestControl.executeEmbed` for time-based tests

See original GitHub issue

I noticed a flake in the server TimeoutSuite yesterday and realized that many/all of our time-based tests are actually running against real time, I believe.

In Cats Effect 3.3 TestControl.executeEmbed was introduced as a way of running an IO against “simulated” time instead of real time. This allows the test to run much more quickly (since it can simulate a sleep instantly, instead of actually sleeping) and more reliably.

Cats Effect docs: https://typelevel.org/cats-effect/docs/core/test-runtime#full-execution

I recently used executeEmbed in https://github.com/typelevel/fs2/pull/2922, as an example 😃

So executeEmbed should be sprinkled in the appropriate places in our test suite. The Timeout suite is a good place to start 😃

https://github.com/http4s/http4s/blob/08d219ba64f08a3741ebf2816f97a81b9561269a/server/shared/src/test/scala/org/http4s/server/middleware/TimeoutSuite.scala#L30

Issue Analytics

State:
Created a year ago
Comments:5 (5 by maintainers)

Top GitHub Comments

1reaction

FrancescoSerracommented, Jun 14, 2022

thanks @armanbilge and sorry for all the trouble!

1reaction

danichegcommented, Jun 14, 2022

I’ve tried to apply TestControl in tests and many times faced with this. But sure, maybe I was doing something wrong, just wanted to add some nota bene 😃

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