How do you mock `rememberLauncherForActivityResult` in Compose? With `registerForActivityResult` you...

# compose

[Philip S]

How do you mock rememberLauncherForActivityResult in Compose? With registerForActivityResult you could send in a registry parameter to prevent the real implementation from being called in UI-tests. However this is missing for the Compose equivalent.

[nitrog42]

I think it's fixed with rc01 ? https://developer.android.com/jetpack/androidx/releases/compose-ui#1.0.0-rc01

[nitrog42]

Compose @Preview now provides a LocalActivityResultRegistryOwner that allows you to preview Composables that use APIs like rememberLauncherForActivityResult() that depend on that owner existing. (Ib13d1, b/185693006)

[nitrog42]

oh sorry I thought it was for the Preview

[Ian Lake]

Just provide your own registry via LocalActivittResultRegistryOwner

[Philip S]

How? I tried:

val registry = registryWrapper.activityResultRegistry

if (registry != null) {
    LocalActivityResultRegistryOwner.provides {
        registry
    }
}
val current = LocalActivityResultRegistryOwner.current?.activityResultRegistry

require(registry == current)

where registry is my mocked registry (i debugged to check that it is not null). rememberLauncherForActivityResult Will still not take my mocked registry and calling .current does not return my mocked registry

[Ian Lake]

I think the piece you're missing is `CompositionLocalProvider`: https://developer.android.com/reference/kotlin/androidx/compose/runtime/package-summary#CompositionLocalProvider(kotlin.Array,kotlin.Function0)

[Ian Lake]

That's what makes that value you provide available to everything under that hierarchy

[Ian Lake]

Take a look at how we test `rememberLauncherForActivityResult`: https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:activity[…]/androidx/activity/compose/ActivityResultRegistryTest.kt;l=77

[Philip S]

It works now thanks for the help