revert remove robolectric - prepare for android navigation stack

lib/android/app/build.gradle

 apply plugin: 'com.android.library'
+apply from: '../prepare-robolectric.gradle'
 
 android {
     compileSdkVersion 25
 
     // tests
     testCompile 'junit:junit:4.12'
+    testCompile 'org.robolectric:robolectric:3.3'
     testCompile 'org.assertj:assertj-core:2.5.0'
     testCompile 'org.mockito:mockito-core:2.7.5'
-    testCompile 'org.json:json:20140107'
 }

lib/android/app/src/test/AndroidManifest.xml

+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+          package="com.reactnativenavigation">
+
+    <application
+        android:name=".TestApplication"
+        android:theme="@style/Theme.AppCompat.Light">
+    </application>
+</manifest>

lib/android/app/src/test/java/com/reactnativenavigation/BaseTest.java

 package com.reactnativenavigation;
 
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(sdk = 25, constants = BuildConfig.class, manifest = "/../../../../../src/test/AndroidManifest.xml")
 public abstract class BaseTest {
 
 }

lib/android/app/src/test/java/com/reactnativenavigation/EnvironmentTest.java

 import com.facebook.react.common.ReactConstants;
 
 import org.junit.Test;
+import org.robolectric.RuntimeEnvironment;
 
 import static org.assertj.core.api.Java6Assertions.assertThat;
 
 	public void androidR() {
 		assertThat(R.string.bottom_sheet_behavior).isNotZero();
 	}
+
+	@Test
+	public void ableToLoadApplication() throws Exception {
+		assertThat(RuntimeEnvironment.application).isNotNull();
+	}
 }

lib/android/app/src/test/java/com/reactnativenavigation/TestApplication.java

+package com.reactnativenavigation;
+
+import android.app.Application;
+
+public class TestApplication extends Application {
+}

lib/android/app/src/test/java/com/reactnativenavigation/utils/UiThreadTest.java

+package com.reactnativenavigation.utils;
+
+import com.reactnativenavigation.BaseTest;
+
+import org.junit.Test;
+import org.robolectric.shadows.ShadowLooper;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyZeroInteractions;
+
+public class UiThreadTest extends BaseTest {
+	@Test
+	public void postOnUiThread() throws Exception {
+		Runnable task = mock(Runnable.class);
+		ShadowLooper.pauseMainLooper();
+		UiThread.post(task);
+		verifyZeroInteractions(task);
+		ShadowLooper.runUiThreadTasks();
+		verify(task, times(1)).run();
+	}
+
+	@Test
+	public void postDelayedOnUiThread() throws Exception {
+		Runnable task = mock(Runnable.class);
+		UiThread.postDelayed(task, 1000);
+		verifyZeroInteractions(task);
+		ShadowLooper.runUiThreadTasksIncludingDelayedTasks();
+		verify(task, times(1)).run();
+	}
+}

lib/android/app/src/test/java/com/reactnativenavigation/utils/UiUtilsTest.java

+package com.reactnativenavigation.utils;
+
+import android.view.View;
+
+import com.reactnativenavigation.BaseTest;
+
+import org.junit.Test;
+import org.robolectric.shadow.api.Shadow;
+
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyZeroInteractions;
+
+public class UiUtilsTest extends BaseTest {
+	@Test
+	public void runOnPreDrawOnce() throws Exception {
+		View view = Shadow.newInstanceOf(View.class);
+		Runnable task = mock(Runnable.class);
+		verifyZeroInteractions(task);
+
+		UiUtils.runOnPreDrawOnce(view, task);
+		view.getViewTreeObserver().dispatchOnPreDraw();
+		verify(task, times(1)).run();
+	}
+}

lib/android/prepare-robolectric.gradle

+def robolectricDependenciesFolder = new File(rootProject.buildDir, "robolectric-3.3-dependencies")
+
+configurations.create('robolectricRuntime')
+
+dependencies {
+    testCompile "org.khronos:opengl-api:gl1.1-android-2.1_r1"
+
+    robolectricRuntime "org.robolectric:android-all:7.1.0_r7-robolectric-0"
+    robolectricRuntime "org.robolectric:shadows-core:3.3"
+    robolectricRuntime "org.robolectric:robolectric-utils:3.3"
+    robolectricRuntime "org.robolectric:robolectric-resources:3.3"
+    robolectricRuntime "org.robolectric:robolectric-processor:3.3"
+    robolectricRuntime "org.robolectric:robolectric-sandbox:3.3"
+    robolectricRuntime "org.robolectric:shadows-support-v4:3.3"
+    robolectricRuntime "org.robolectric:shadows-multidex:3.3"
+    robolectricRuntime "org.robolectric:shadows-play-services:3.3"
+    robolectricRuntime "org.robolectric:shadows-maps:3.3"
+}
+
+rootProject.task(type: Copy, overwrite: true, "downloadRobolectricDependencies") {
+    println "downloadRobolectricDependencies into " + robolectricDependenciesFolder
+    from configurations.robolectricRuntime
+    into robolectricDependenciesFolder
+}
+
+project.afterEvaluate {
+    tasks.all {
+        if (it.name.startsWith("test")) {
+            it.dependsOn(rootProject.tasks.findByName("downloadRobolectricDependencies"))
+        }
+    }
+}
+
+android {
+    testOptions {
+        unitTests.all {
+            systemProperty 'robolectric.offline', 'true'
+            systemProperty 'robolectric.dependency.dir', robolectricDependenciesFolder
+        }
+    }
+}
+