Question about testing ktor. Has anyone had luck mocking an ApplicationRequest? I'd like to be able to write unit tests without the whole test server harness, which has been fine for integration testing but a bit much for unit tests. Specifically, I just want to test a function that parses a request, so I just want to pass my function a test request without having to make a call to the test server to get one

I don’t use ktor, but the advice remains the same for any code - “don’t mock what you don’t own”. Is

ApplicationRequest

an object you can construct?

Technically, yes, but it's a huge pain to construct. Using the test harness is the easiest way to, and that's what I'm trying to move away from

How about introducing your own abstraction layer to only expose the parts you want? You could create an interface to expose the data you’re interested in in your code under test, then for production it’s a simple wrapper around

ApplicationRequest

to forward the values.

Right, I definitely still want the request level integration tests; I just also want to be able to unit test everything within the request that doesn't need to know about ktor

If you have integration level tests covering your behaviour, do you need the unit tests?

It's easier to test more cases with unit testing. It becomes very cumbersome with integration tests and because of the excess setup tends to obfuscate what is actually being tested

Agree on the first, the second can be mitigated though

True, I can always use some test utils to move setup out of the tests themselves, but then I still have more code to maintain and too many test utils like this can make the tests brittle to change and sometimes lead to false positives if you aren't careful so I try to avoid indirection whenever possible in tests and keep it very dumb.

You can also try #http4k 😅 (hides)

http4k looks really nice, and the service I'm working is new and small enough to give it a spin without much extra effort - thanks for the rec!