Snapshots tests for android for a remote device such as Firebase Test Lab (Bitrise)

screenshots.gradle

apply plugin: 'shot'
/*
Put this on any module you want to test with snapshots:
apply from: "../screenshots.gradle"

Put this on your root build.gradle
buildscript {
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.karumi:shot:3.1.0'
    }
}

Here some example of instrumentation test:
@RunWith(AndroidJUnit4::class)
class MainActivityTest {

    @Rule
    @JvmField
    val rule = ActivityTestRule(MainActivity::class.java, true, false)

    @Test
    fun testSnapshot() {
        rule.launchActivity(Intent())
        Screenshot.snapActivity(rule.activity)
            .record()
    }
}

class SampleTestRunner : AndroidJUnitRunner() {
    override fun onCreate(args: Bundle) {
        ScreenshotRunner.onCreate(this, args)
        super.onCreate(args)
    }

    override fun finish(resultCode: Int, results: Bundle) {
        ScreenshotRunner.onDestroy()
        super.finish(resultCode, results)
    }
}

 * `./gradlew executeScreenshotTests -Precord` - Executes snapshots recording at folder  `"${projectDir}/screenshots/`
 * `./gradlew executeScreenshotTests` - Verifies if the current screens against the previous snapshots at folder  `"${projectDir}/screenshots/` using the current connected device
 * `./gradlew copyVerificationFiles executeScreenshotTests -PrunInstrumentation=false` - Verifies if the current screens against the previous snapshots at folder  `"${projectDir}/screenshots/` without using the current connected device.
 In that case the current screenshots(that may be generated on a remote device) must be copied to the folder `"${projectDir}/screenshots/screenshots-default`

*/

ext {
    localProp = new Properties()
    fileName = 'local.properties'
    if (project.rootProject.file(fileName).exists()) {
        localProp.load(new FileInputStream(rootProject.file(fileName)))
    }
    screenShotsRecordedBaseDir =
            System.env.VDTESTING_DOWNLOADED_FILES_DIR != null ?
                    "${System.env.VDTESTING_DOWNLOADED_FILES_DIR}" :
                    getArgument("screenShotsRecordedBaseDir", "${project.buildDir}/reports/shot/record/images/recorded")
    screenShotsVerificationBaseDir =
            System.env.SCREENSHOTS_VERIFICATION_BASE_DIR != null ?
                    System.env.SCREENSHOTS_VERIFICATION_BASE_DIR :
                    getArgument("screenShotsVerificationBaseDir", "${projectDir}/screenshots/screenshots-default")
}

shot {
    appId = 'your.package.id'
    runInstrumentation = Boolean.valueOf(getArgument("runInstrumentation", "true"))
}

project.afterEvaluate {

    task copyVerificationFiles() {
        doFirst {
            println("screenShotsRecordedBaseDir=${screenShotsRecordedBaseDir}")
            println("screenShotsVerificationBaseDir=${screenShotsVerificationBaseDir}")
        }

        fileTree(dir: "${screenShotsRecordedBaseDir}")
                .filter { f ->
                    f.name.contains("_screenshots-default_")
                }.each { foundFile ->
            def nameWithoutPrefix = foundFile.name.split("_screenshots-default_")[1]

            copy {
                from "${foundFile.path}"
                into "${screenShotsVerificationBaseDir}"
                rename { String fileName ->
                    fileName.replace(foundFile.name, nameWithoutPrefix)
                }
            }
        }
    }
    //This ensures that the screenshots are recorded when running on Firebase test lab 
    project.tasks.connectedDebugAndroidTest.finalizedBy project.tasks.executeScreenshotTests
}

private def getArgument(prop, defaultValue) {
    def r = project.hasProperty(prop) ? project.getProperties().get(prop) : defaultValue
    println("${prop}=${r}")
    return r
}