Custom Filter

FlavorFilter.kt

package com.stepstone.base.test.runner.filter


import android.os.Bundle
import com.stepstone.base.BuildConfig
import com.stepstone.base.test.runner.annotation.TestFilter
import org.junit.runner.Description
import timber.log.Timber

/**
 * Filter used to determine if a test should be executed or not.
 *
 * This does the following:
 *
 * - runs all tests if 'class' bundle argument was provided to the runner (this means that either Android Test Orchestrator wants to run a single test or that we want to run a test from Android Studio directly)
 * - checks if [TestFilter] is present on a test method -> if so it filters the test based on that annotation
 * - checks if [TestFilter] is present on a test class -> if so it filters the test based on that annotation
 * - otherwise it runs the test
 *
 *
 * [TestFilter] filtering runs the following checks in order:
 *
 * - if flavor is not present in [TestFilter.flavors] it will not run the test
 * - if flavor is present in [TestFilter.notFlavors] it will not run the test
 *
 * To run a test on a single flavor e.g. flavor1 you need to add [TestFilter] to a test method like this:
 *
 * `@TestFilter(flavors = [FLAVOR_1])`
 *
 * To run a test on all flavors but one (flavor4) you need to add [TestFilter] to a test method like this:
 *
 * `@TestFilter(notFlavors = [FLAVOR_4])`
 *
 * @see org.junit.runner.manipulation.Filter
 */
class FlavorFilter(bundle: Bundle) : ParentFilter() {

    companion object {

        private const val CLASS_BUNDLE_KEY = "class"

    }

    private val shouldFilterTests: Boolean

    init {
        Timber.i("FlavorFilter bundle: %s", bundle)
        val listTestsForOrchestrator = java.lang.Boolean.parseBoolean(bundle.getString("listTestsForOrchestrator", "false"))
        val runsSingleClass = bundle.containsKey(CLASS_BUNDLE_KEY)
        shouldFilterTests = listTestsForOrchestrator && !runsSingleClass
    }

    override fun evaluateTest(description: Description): Boolean {
        if (!shouldFilterTests) {
            return true
        }

        val classTestFilter = description.testClass.getAnnotation(TestFilter::class.java)
        val testFilter = description.getAnnotation(TestFilter::class.java)
        if (testFilter != null) {
            return evaluateTestWithFilter(testFilter)
        } else if (classTestFilter != null) {
            return evaluateTestWithFilter(classTestFilter)
        }
        
        return true
    }

    private fun evaluateTestWithFilter(testFilter: TestFilter): Boolean {
        val filters = testFilter.filters
        val notFilters = testFilter.notFilters
        return (filters.contains(BuildConfig.FLAVOR)
                && !notFilters.contains(BuildConfig.FLAVOR))
    }

    override fun describe(): String {
        return "Flavor filter"
    }

}