A modern programming language that makes developers happier.

kotlinlang

Is it possible to test Compose without running the test on a device/emulator?

I’ve followed <https://developer.android.com/jetpack/compose/testing|the testing docs>  but these tests require a device (it seems). I’m wondering if it’s possible to run the tests with Robolectric or even just JVM? There are some previous <https://kotlinlang.slack.com/archives/CJLTWPH7S/p1557766445136100|threads> from last year mentioning this but I don’t see any examples.

it should work fine with robolectric, we have a few robolectric tests lurking around in compose itself

compose-desktop of course runs on a local jvm, but not if you are testing things that have other android dependencies

If you have any of those Robolectric tests from within compose handy could you link them? I was trying to write some in Robolectric but I kept getting:
```java.lang.IllegalStateException: Functions that involve synchronization (Assertions, Actions, Synchronization; e.g. assertIsSelected(), doClick(), runOnIdle()) cannot be run from the main thread. Did you nest such a function inside runOnIdle {}, runOnUiThread {} or setContent {}?```

looks like there are definitely some workarounds floating about in these: <https://cs.android.com/androidx/platform/frameworks/support/+/androidx-master-dev:compose/ui/ui/src/test/kotlin/androidx/compose/ui/test/ComposeUiRobolectricTestRunner.kt;l=37>

<@UJBKXD0HH> I thought each composable would be able to be tested on the jvm. Maybe I misinterpreted something from months ago. I don't think it's the worst thing if I need to test my composables on device. Anything that gets me away from robolectric because that always ends up being a dumpster fire.

If you write a composable function like
```ContextAmbient.current.getSystemService(...)...```
then that's a platform-specific composable :slightly_smiling_face:

if you have composables that are platform-agnostic, then those will work host-side just fine

<@U01CG5P4WJE> did you get robolectric tests up and running?

Hey <@U01AYG2KABZ>, I was able to test Composables if I used <https://cs.android.com/androidx/platform/frameworks/support/+/androidx-master-dev:compose/ui/ui/src/test/kotlin/androidx/compose/ui/test/ComposeUiRobolectricTestRunner.kt;l=37|this runner> or upgraded to Robolectric 4.4. However, there are some view-testing function such as `assertIsDisplayed()` (<https://developer.android.com/reference/kotlin/androidx/compose/ui/test/package-summary#(androidx.compose.ui.test.SemanticsNodeInteraction).assertIsDisplayed()|this>) that I never figured out how to get working in Robolectric.

Did you create your own copy of the runner?

Hi Allan. Right, I copied the `ComposeUiRobolectricTestRunner` into my project. Then I set it as the runner for Robolectric tests like so:
```@RunWith(ComposeUiRobolectricTestRunner::class)
class YourComposableTest {
....```
hope that helps!