Helper functions that introduce some sugar DSL around TestVariant and ApkVariantOutput instances.

SugarVariantOutputDSL.kt

/**
 * Yields all available variants of type [TestVariant].
 */
internal fun DomainObjectCollection<out BaseVariant>.forEachTestVariant(block: (TestVariant) -> Unit) {
    all { variant ->
        when (variant) {
            is ApplicationVariant -> variant.testVariant?.let(block)
            is TestVariant -> block(variant)
            is LibraryVariant -> variant.testVariant?.let(block)
        }
    }
}

/**
 * Yields packaging output for the [TestVariant].
 */
internal fun TestVariant.forEachApkOutput(block: (ApkVariantOutput) -> Unit) {
    outputs.all { output ->
        if (output is ApkVariantOutput) {
            block(output)
        } else {
            throw IllegalArgumentException("Unexpected output type for variant $name: ${output::class.java}")
        }
    }
}