Is there an idiomatic way to override the default ...

# coroutines

[ashdavies]

Is there an idiomatic way to override the default dispatcher for unit tests? or would this be considered bad practice, and typical injection preferred?

[gildor]

What is your use case for this?
You can specify amount of threads for default dispathcer, but there is no way to completely replace it (except reflections), usually it shouldn’t be a problem for unit tests if you just use suspend functions and test them or just have access to Job

[ashdavies]

It’s only when unit testing classes that construct a coroutine consuming suspended functions, it needs to provided with a dispatcher or scope via constructor injection which can be changed under test.

[ashdavies]

Most samples hard code Dispatchers.main, which made me wonder if there was an alternative without using hacky methods

[spand]

I treat it as any other static dependency and pass it in.

[gildor]

For UI dispatcher you always should provide it

[gildor]

or use own dispather that allows to switch implementation for UI

[gildor]

It’s the same for non-coroutine code

[gildor]

In general it’s good style to use suspend functions or use launch/async but always return Job, so you can test such function easily

[ashdavies]

Yep, I figured as much, I just thought I’d ask 👍