Remove the custom GleanTestRunner

samples/android/app/build.gradle

@@ -20,7 +20,7 @@ android {
         versionCode 1
         versionName "1.0"
 
-        testInstrumentationRunner "org.mozilla.samples.gleancore.GleanTestRunner"
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
 
     buildTypes {

samples/android/app/src/androidTest/java/org/mozilla/samples/gleancore/GleanTestRunner.kt

@@ -1,89 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-package org.mozilla.samples.gleancore
-
-import androidx.annotation.VisibleForTesting
-import androidx.test.platform.app.InstrumentationRegistry
-import androidx.test.runner.AndroidJUnitRunner
-import okhttp3.mockwebserver.Dispatcher
-import okhttp3.mockwebserver.MockResponse
-import okhttp3.mockwebserver.MockWebServer
-import okhttp3.mockwebserver.RecordedRequest
-
-/**
- * Create a mock webserver that accepts all requests and replies with "OK".
- * @return a [MockWebServer] instance
- */
-private fun createMockWebServer(): MockWebServer {
-    val server = MockWebServer()
-    server.setDispatcher(object : Dispatcher() {
-        override fun dispatch(request: RecordedRequest): MockResponse {
-            return MockResponse().setBody("OK")
-        }
-    })
-    return server
-}
-
-/**
- * Returns the currently active instance of the ping server.
- *
- * @return the active [MockWebServer] instance
- */
-@VisibleForTesting(otherwise = VisibleForTesting.NONE)
-internal fun getPingServer(): MockWebServer {
-    val testRunner: GleanTestRunner = InstrumentationRegistry.getInstrumentation() as GleanTestRunner
-    return testRunner.pingServer
-}
-
-/**
- * Returns the port the local ping server is listening to.
- *
- * @return a `Int` containing the server address.
- */
-@VisibleForTesting(otherwise = VisibleForTesting.NONE)
-internal fun getPingServerPort(): Int {
-    val testRunner: GleanTestRunner = InstrumentationRegistry.getInstrumentation() as GleanTestRunner
-    return testRunner.pingServerPort!!
-}
-
-/**
- * The test runner to be used in the instrumentation tests for the Glean SDK
- * sample app in order to point it to a local ping server.
- */
-@VisibleForTesting(otherwise = VisibleForTesting.NONE)
-class GleanTestRunner : AndroidJUnitRunner() {
-    // Add a lazy ping server to the app runner. This is only initialized once
-    // since the `Application` object is re-used.
-    internal val pingServer: MockWebServer by lazy { createMockWebServer() }
-    internal var pingServerPort: Int? = null
-
-    init {
-        // We need to start the server off the main thread, otherwise
-        // Android will throw a `NetworkOnMainThreadException`. Spawning
-        // a thread and joining seems fine.
-        val thread = Thread {
-            pingServer.start()
-            pingServerPort = pingServer.port
-        }
-        thread.start()
-        thread.join()
-    }
-
-    /**
-     * Called before the application code runs, this starts the ping server.
-     */
-    override fun onStart() {
-        super.onStart()
-        pingServer.start()
-    }
-
-    /**
-     * Called after the application code cleans up, this stops the ping server.
-     */
-    override fun onDestroy() {
-        super.onDestroy()
-        pingServer.shutdown()
-    }
-}