Revert "Remove abandoned implementation."

Revert submission 3242160-remove-messaging-package

Reason for revert: Droidmonitor created revert due to b/364617310, b/364626927, b/364617560

Reverted changes: /q/submissionid:3241481-remove-messaging-package

This reverts commit 93b5e63726.

Change-Id: I182cbf1758988d9a4950d39354266a5fb3aaabce

tests/src/com/android/messaging/TestUtil.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.messaging;
+
+import android.appwidget.AppWidgetManager;
+import android.content.ComponentName;
+import android.content.Context;
+import android.os.PowerManager;
+import android.test.InstrumentationTestCase;
+
+import com.android.messaging.util.LogUtil;
+import com.android.messaging.widget.BugleWidgetProvider;
+import com.android.messaging.widget.WidgetConversationProvider;
+
+import junit.framework.TestCase;
+
+import org.mockito.MockitoAnnotations;
+
+/**
+ * Helpers that can be called from all test base classes to 'reset' state and prevent as much as
+ * possible having side effects leak from one test to another.
+ */
+public class TestUtil {
+    public static void testSetup(final Context context, final TestCase testCase) {
+        haltIfTestsAreNotAbleToRun(context);
+
+        // Workaround to get mockito to work.
+        // See https://code.google.com/p/dexmaker/issues/detail?id=2. TODO: Apparently
+        // solvable by using a different runner.
+        System.setProperty("dexmaker.dexcache",
+                context.getCacheDir().getPath());
+
+        // Initialize @Mock objects.
+        MockitoAnnotations.initMocks(testCase);
+
+        // Tests have to explicitly override this
+        Factory.setInstance(null);
+    }
+
+    public static void testTeardown(final TestCase testCase) {
+        if (testCase instanceof InstrumentationTestCase) {
+            // Make sure the test case is finished running or we'll get NPEs when accessing
+            // Fragment.get()
+            ((InstrumentationTestCase) testCase).getInstrumentation().waitForIdleSync();
+        }
+        Factory.setInstance(null);
+    }
+
+    private static void haltIfTestsAreNotAbleToRun(final Context context) {
+        final PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
+        if (!pm.isScreenOn()) {
+            // Ideally we could turn it on for you using the WindowManager, but we currently run
+            // the tests independently of the activity life cycle.
+            LogUtil.wtf(LogUtil.BUGLE_TAG, "You need to turn on your screen to run tests!");
+        }
+
+        final AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);
+        int [] conversationWidgetIds = appWidgetManager.getAppWidgetIds(new ComponentName(context,
+                WidgetConversationProvider.class));
+        int [] conversationListWidgetIds = appWidgetManager.getAppWidgetIds(new
+                ComponentName(context, BugleWidgetProvider.class));
+
+        if ((conversationWidgetIds.length > 0) || (conversationListWidgetIds.length > 0)) {
+            // Currently widgets asynchronously access our content providers and singletons which
+            // interacts badly with our test setup and tear down.
+            LogUtil.wtf(LogUtil.BUGLE_TAG, "You currently can't reliably run unit tests" +
+                    " with a Messaging widget on your desktop!");
+        }
+    }
+}