Interface you can import from your tests to be able to use screenshot testing for Android with different resolutions easily

ScreenshotTest.kt

import android.app.Activity
import android.app.Dialog
import android.content.Context
import android.view.View
import androidx.fragment.app.Fragment
import androidx.test.platform.app.InstrumentationRegistry
import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
import com.facebook.testing.screenshot.Screenshot
import com.facebook.testing.screenshot.ViewHelpers
import com.facebook.testing.screenshot.internal.TestNameDetector

interface ScreenshotTest {

    val context: Context get() = InstrumentationRegistry.getInstrumentation().targetContext

    fun compareScreenshot(
        activity: Activity,
        heightInPx: Int? = null,
        backgroundColor: Int = R.color.white
    ) {
        waitForAnimationsToFinish()
        val view = activity.findViewById<View>(android.R.id.content)
        runOnUi {
            view.setBackgroundResource(backgroundColor)
        }
        compareScreenshot(view = view!!, heightInPx = heightInPx)
    }

    fun compareScreenshot(dialog: Dialog) {
        val window = dialog.window
        if (window != null) {
            waitForAnimationsToFinish()
            compareScreenshot(window.decorView)
        }
    }

    fun compareScreenshot(view: View, heightInPx: Int? = null, name: String? = null) {
        waitForAnimationsToFinish()
        Device.values().forEach {
            val heightInDp = heightInPx ?: it.height
            runOnUi {
                ViewHelpers.setupView(view)
                    .setExactHeightPx(heightInDp)
                    .setExactWidthPx(it.width)
                    .layout()
            }
            val testName = name ?: TestNameDetector.getTestName()
            Screenshot
                .snap(view)
                .setName("${TestNameDetector.getTestClass()}_${testName}_${it.name}")
                .setDescription("${it.name}-${it.width}x${it.height}")
                .record()
        }
    }

    fun compareScreenshot(fragment: Fragment, heightInPx: Int) =
        compareScreenshot(fragment.view!!, heightInPx)

    fun waitForAnimationsToFinish() {
        getInstrumentation().waitForIdleSync()
    }

    fun runOnUi(block: () -> Unit) {
        getInstrumentation().runOnMainSync { block() }
    }
}

@Suppress("unused")
enum class Device(val width: Int, val height: Int) {
    SMALLEST(640, 1136),
    HUAWEI_P8_LITE(720, 1280),
    PIXEL4_XL((1440 / 1.82).toInt(), (3040 / 1.82).toInt()),
    SAMSUNG_GALAXY_S7_EDGE((1440 / 1.81).toInt(), (2560 / 1.81).toInt())
}