SoTest.kt

import android.app.Activity
import android.content.pm.ActivityInfo
import androidx.compose.foundation.layout.Column
import androidx.compose.material.Button
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.platform.LocalConfiguration
import androidx.compose.ui.platform.LocalContext
import androidx.compose.ui.test.assertIsDisplayed
import androidx.compose.ui.test.junit4.createComposeRule
import androidx.compose.ui.test.onNodeWithText
import androidx.compose.ui.test.performClick
import org.junit.Rule
import org.junit.Test

class SoTest {

    @get:Rule
    val composeRule = createComposeRule()

    @Test
    fun test() {
        composeRule.setContent { MyApp() }

        // Starts with portrait
        composeRule.onNodeWithText("P").assertIsDisplayed()
        // Change the orientation to Landscape
        composeRule.onNodeWithText("DO IT").performClick()
        // Now the text should be `L`
        composeRule.onNodeWithText("L").assertIsDisplayed()
    }

    @Composable
    fun MyApp() {
        val currentOrientation = LocalConfiguration.current.orientation
        val orientation = if (currentOrientation == ActivityInfo.SCREEN_ORIENTATION_PORTRAIT) {
                "P"
            } else {
                "L"
            }
        val activity = LocalContext.current as Activity
        Column {
            Text(text = orientation)
            Button(onClick = {
                // change orientation to landscape
                activity.requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE
            }) {
                Text(text = "DO IT")
            }
        }
    }
}