Add beginning of a ViewModel test

mostly to demonstrate how those could look like

briar-android/build.gradle

@@ -126,10 +126,11 @@ dependencies {
 	testImplementation 'androidx.test:runner:1.3.0'
 	testImplementation 'androidx.test.ext:junit:1.1.2'
 	testImplementation 'androidx.fragment:fragment-testing:1.2.5'
+	testImplementation "androidx.arch.core:core-testing:2.1.0"
 	testImplementation "androidx.test.espresso:espresso-core:$espressoVersion"
 	testImplementation 'org.robolectric:robolectric:4.3.1'
 	testImplementation 'org.mockito:mockito-core:3.1.0'
-	testImplementation 'junit:junit:4.12'
+	testImplementation 'junit:junit:4.13.1'
 	testImplementation "org.jmock:jmock:$jmockVersion"
 	testImplementation "org.jmock:jmock-junit4:$jmockVersion"
 	testImplementation "org.jmock:jmock-legacy:$jmockVersion"

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/AddContactViewModel.java

@@ -12,6 +12,7 @@ import org.briarproject.bramble.api.db.NoSuchPendingContactException;
 import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.viewmodel.DbViewModel;
 import org.briarproject.briar.android.viewmodel.LiveEvent;
 import org.briarproject.briar.android.viewmodel.LiveResult;
@@ -54,8 +55,9 @@ public class AddContactViewModel extends DbViewModel {
 			ContactManager contactManager,
 			@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager,
-			TransactionManager db) {
-		super(application, dbExecutor, lifecycleManager, db);
+			TransactionManager db,
+			AndroidExecutor androidExecutor) {
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.contactManager = contactManager;
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/PendingContactListViewModel.java

@@ -19,6 +19,7 @@ import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.rendezvous.RendezvousPoller;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousPollEvent;
+import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.viewmodel.DbViewModel;
 
 import java.util.ArrayList;
@@ -58,10 +59,11 @@ public class PendingContactListViewModel extends DbViewModel
 			@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager,
 			TransactionManager db,
+			AndroidExecutor androidExecutor,
 			ContactManager contactManager,
 			RendezvousPoller rendezvousPoller,
 			EventBus eventBus) {
-		super(application, dbExecutor, lifecycleManager, db);
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.contactManager = contactManager;
 		this.rendezvousPoller = rendezvousPoller;
 		this.eventBus = eventBus;

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationViewModel.java

@@ -22,6 +22,7 @@ import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.attachment.AttachmentCreator;
 import org.briarproject.briar.android.attachment.AttachmentManager;
 import org.briarproject.briar.android.attachment.AttachmentResult;
@@ -106,6 +107,7 @@ public class ConversationViewModel extends DbViewModel
 			@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager,
 			TransactionManager db,
+			AndroidExecutor androidExecutor,
 			EventBus eventBus,
 			MessagingManager messagingManager,
 			ContactManager contactManager,
@@ -113,7 +115,7 @@ public class ConversationViewModel extends DbViewModel
 			PrivateMessageFactory privateMessageFactory,
 			AttachmentRetriever attachmentRetriever,
 			AttachmentCreator attachmentCreator) {
-		super(application, dbExecutor, lifecycleManager, db);
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.db = db;
 		this.eventBus = eventBus;
 		this.messagingManager = messagingManager;

briar-android/src/main/java/org/briarproject/briar/android/conversation/ImageViewModel.java

@@ -15,6 +15,7 @@ import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.attachment.AttachmentItem;
 import org.briarproject.briar.android.viewmodel.DbViewModel;
 import org.briarproject.briar.android.viewmodel.LiveEvent;
@@ -80,8 +81,9 @@ public class ImageViewModel extends DbViewModel implements EventListener {
 			@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager,
 			TransactionManager db,
+			AndroidExecutor androidExecutor,
 			@IoExecutor Executor ioExecutor) {
-		super(application, dbExecutor, lifecycleManager, db);
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.messagingManager = messagingManager;
 		this.eventBus = eventBus;
 		this.ioExecutor = ioExecutor;

briar-android/src/main/java/org/briarproject/briar/android/navdrawer/NavDrawerViewModel.java

@@ -9,6 +9,7 @@ import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
+import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.viewmodel.DbViewModel;
 
 import java.util.concurrent.Executor;
@@ -53,8 +54,9 @@ public class NavDrawerViewModel extends DbViewModel {
 			@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager,
 			TransactionManager db,
+			AndroidExecutor androidExecutor,
 			SettingsManager settingsManager) {
-		super(app, dbExecutor, lifecycleManager, db);
+		super(app, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.settingsManager = settingsManager;
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/navdrawer/PluginViewModel.java

@@ -29,6 +29,7 @@ import org.briarproject.bramble.api.plugin.event.TransportStateEvent;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.bramble.api.settings.event.SettingsUpdatedEvent;
+import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.viewmodel.DbViewModel;
 
 import java.util.concurrent.Executor;
@@ -87,9 +88,10 @@ public class PluginViewModel extends DbViewModel implements EventListener {
 	@Inject
 	PluginViewModel(Application app, @DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager, TransactionManager db,
-			SettingsManager settingsManager, PluginManager pluginManager,
-			EventBus eventBus, NetworkManager networkManager) {
-		super(app, dbExecutor, lifecycleManager, db);
+			AndroidExecutor androidExecutor, SettingsManager settingsManager,
+			PluginManager pluginManager, EventBus eventBus,
+			NetworkManager networkManager) {
+		super(app, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.app = app;
 		this.settingsManager = settingsManager;
 		this.pluginManager = pluginManager;

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupListViewModel.java

@@ -20,6 +20,7 @@ import org.briarproject.bramble.api.sync.ClientId;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.event.GroupAddedEvent;
 import org.briarproject.bramble.api.sync.event.GroupRemovedEvent;
+import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.briar.android.viewmodel.DbViewModel;
 import org.briarproject.briar.android.viewmodel.LiveResult;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
@@ -78,11 +79,12 @@ class GroupListViewModel extends DbViewModel implements EventListener {
 			@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager,
 			TransactionManager db,
+			AndroidExecutor androidExecutor,
 			PrivateGroupManager groupManager,
 			GroupInvitationManager groupInvitationManager,
 			ContactManager contactManager,
 			AndroidNotificationManager notificationManager, EventBus eventBus) {
-		super(application, dbExecutor, lifecycleManager, db);
+		super(application, dbExecutor, lifecycleManager, db, androidExecutor);
 		this.groupManager = groupManager;
 		this.groupInvitationManager = groupInvitationManager;
 		this.contactManager = contactManager;

briar-android/src/main/java/org/briarproject/briar/android/viewmodel/DbViewModel.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.viewmodel;
 
 import android.app.Application;
-import android.os.Handler;
 
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbCallable;
@@ -10,6 +9,7 @@ import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.AndroidExecutor;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -27,7 +27,6 @@ import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.recyclerview.widget.RecyclerView;
 
-import static android.os.Looper.getMainLooper;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logException;
@@ -42,16 +41,19 @@ public abstract class DbViewModel extends AndroidViewModel {
 	private final Executor dbExecutor;
 	private final LifecycleManager lifecycleManager;
 	private final TransactionManager db;
+	private final AndroidExecutor androidExecutor;
 
 	public DbViewModel(
 			@NonNull Application application,
 			@DatabaseExecutor Executor dbExecutor,
 			LifecycleManager lifecycleManager,
-			TransactionManager db) {
+			TransactionManager db,
+			AndroidExecutor androidExecutor) {
 		super(application);
 		this.dbExecutor = dbExecutor;
 		this.lifecycleManager = lifecycleManager;
 		this.db = db;
+		this.androidExecutor = androidExecutor;
 	}
 
 	/**
@@ -103,8 +105,8 @@ public abstract class DbViewModel extends AndroidViewModel {
 				Thread.currentThread().interrupt();
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);
-				new Handler(getMainLooper())
-						.post(() -> uiUpdate.call(new LiveResult<>(e)));
+				androidExecutor.runOnUiThread(
+						() -> uiUpdate.call(new LiveResult<>(e)));
 			}
 		});
 	}

briar-android/src/test/java/org/briarproject/briar/android/AndroidExecutorTestImpl.java

@@ -0,0 +1,36 @@
+package org.briarproject.briar.android;
+
+import org.briarproject.bramble.api.system.AndroidExecutor;
+
+import java.util.concurrent.Callable;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Future;
+
+public class AndroidExecutorTestImpl implements AndroidExecutor {
+
+	private final Executor executor;
+
+	public AndroidExecutorTestImpl(Executor executor) {
+		this.executor = executor;
+	}
+
+	@Override
+	public <V> Future<V> runOnBackgroundThread(Callable<V> c) {
+		throw new IllegalStateException("not implemented");
+	}
+
+	@Override
+	public void runOnBackgroundThread(Runnable r) {
+		executor.execute(r);
+	}
+
+	@Override
+	public <V> Future<V> runOnUiThread(Callable<V> c) {
+		throw new IllegalStateException("not implemented");
+	}
+
+	@Override
+	public void runOnUiThread(Runnable r) {
+		executor.execute(r);
+	}
+}

briar-android/src/test/java/org/briarproject/briar/android/privategroup/list/GroupListViewModelTest.java

@@ -0,0 +1,212 @@
+package org.briarproject.briar.android.privategroup.list;
+
+import android.app.Application;
+
+import org.briarproject.bramble.api.contact.Contact;
+import org.briarproject.bramble.api.contact.ContactManager;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.db.TransactionManager;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.event.EventListener;
+import org.briarproject.bramble.api.identity.AuthorInfo;
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.sync.Group;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.bramble.test.BrambleMockTestCase;
+import org.briarproject.bramble.test.DbExpectations;
+import org.briarproject.bramble.test.ImmediateExecutor;
+import org.briarproject.briar.android.AndroidExecutorTestImpl;
+import org.briarproject.briar.android.viewmodel.LiveResult;
+import org.briarproject.briar.api.android.AndroidNotificationManager;
+import org.briarproject.briar.api.privategroup.PrivateGroup;
+import org.briarproject.briar.api.privategroup.PrivateGroupManager;
+import org.briarproject.briar.api.privategroup.event.GroupDissolvedEvent;
+import org.briarproject.briar.api.privategroup.invitation.GroupInvitationItem;
+import org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager;
+import org.jmock.Expectations;
+import org.jmock.lib.legacy.ClassImposteriser;
+import org.junit.Rule;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.Executor;
+
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule;
+
+import static edu.emory.mathcs.backport.java.util.Collections.emptyList;
+import static edu.emory.mathcs.backport.java.util.Collections.singletonList;
+import static org.briarproject.bramble.test.TestUtils.getAuthor;
+import static org.briarproject.bramble.test.TestUtils.getContact;
+import static org.briarproject.bramble.test.TestUtils.getGroup;
+import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
+import static org.briarproject.briar.android.viewmodel.LiveDataTestUtil.getOrAwaitValue;
+import static org.briarproject.briar.api.client.MessageTracker.GroupCount;
+import static org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager.CLIENT_ID;
+import static org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager.MAJOR_VERSION;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+public class GroupListViewModelTest extends BrambleMockTestCase {
+
+	@Rule
+	public final InstantTaskExecutorRule testRule =
+			new InstantTaskExecutorRule();
+
+	private final LifecycleManager lifecycleManager =
+			context.mock(LifecycleManager.class);
+	private final TransactionManager db =
+			context.mock(TransactionManager.class);
+	private final PrivateGroupManager groupManager =
+			context.mock(PrivateGroupManager.class);
+	private final GroupInvitationManager groupInvitationManager =
+			context.mock(GroupInvitationManager.class);
+	private final ContactManager contactManager =
+			context.mock(ContactManager.class);
+	private final AndroidNotificationManager notificationManager =
+			context.mock(AndroidNotificationManager.class);
+	private final EventBus eventBus = context.mock(EventBus.class);
+
+	private final GroupListViewModel viewModel;
+
+
+	private final Group g1 = getGroup(CLIENT_ID, MAJOR_VERSION);
+	private final Group g2 = getGroup(CLIENT_ID, MAJOR_VERSION);
+	private final PrivateGroup privateGroup1 =
+			new PrivateGroup(g1, "foo", getAuthor(), getRandomBytes(2));
+	private final PrivateGroup privateGroup2 =
+			new PrivateGroup(g2, "bar", getAuthor(), getRandomBytes(2));
+	private final AuthorInfo authorInfo1 =
+			new AuthorInfo(AuthorInfo.Status.UNVERIFIED);
+	private final AuthorInfo authorInfo2 =
+			new AuthorInfo(AuthorInfo.Status.VERIFIED);
+
+	private final GroupCount groupCount1 = new GroupCount(2, 1, 23L);
+	private final GroupCount groupCount2 = new GroupCount(5, 3, 42L);
+	private final GroupItem item1 =
+			new GroupItem(privateGroup1, authorInfo1, groupCount1, false);
+	private final GroupItem item2 =
+			new GroupItem(privateGroup2, authorInfo2, groupCount2, false);
+
+	public GroupListViewModelTest() {
+		context.setImposteriser(ClassImposteriser.INSTANCE);
+		Application app = context.mock(Application.class);
+		context.checking(new Expectations() {{
+			oneOf(eventBus).addListener(with(any(EventListener.class)));
+		}});
+		Executor dbExecutor = new ImmediateExecutor();
+		AndroidExecutor androidExecutor =
+				new AndroidExecutorTestImpl(dbExecutor);
+		viewModel = new GroupListViewModel(app, dbExecutor, lifecycleManager,
+				db, androidExecutor, groupManager, groupInvitationManager,
+				contactManager, notificationManager, eventBus);
+	}
+
+	@Test
+	public void testLoadGroupsException() throws Exception {
+		DbException dbException = new DbException();
+
+		Transaction txn = new Transaction(null, true);
+		context.checking(new DbExpectations() {{
+			oneOf(lifecycleManager).waitForDatabase();
+			oneOf(db).transaction(with(true), withDbRunnable(txn));
+			oneOf(groupManager).getPrivateGroups(txn);
+			will(throwException(dbException));
+		}});
+
+		viewModel.loadGroups();
+
+		LiveResult<List<GroupItem>> result =
+				getOrAwaitValue(viewModel.getGroupItems());
+		assertTrue(result.hasError());
+		assertEquals(dbException, result.getException());
+		assertNull(result.getResultOrNull());
+	}
+
+	@Test
+	public void testLoadGroups() throws Exception {
+		Transaction txn = new Transaction(null, true);
+		context.checking(new DbExpectations() {{
+			oneOf(lifecycleManager).waitForDatabase();
+			oneOf(db).transaction(with(true), withDbRunnable(txn));
+			oneOf(groupManager).getPrivateGroups(txn);
+			will(returnValue(Arrays.asList(privateGroup1, privateGroup2)));
+		}});
+		expectLoadGroup(txn, privateGroup1, authorInfo1, groupCount1, false);
+		expectLoadGroup(txn, privateGroup2, authorInfo2, groupCount2, false);
+
+		viewModel.loadGroups();
+
+		// unpack updated live data
+		LiveResult<List<GroupItem>> result =
+				getOrAwaitValue(viewModel.getGroupItems());
+		assertFalse(result.hasError());
+		List<GroupItem> liveList = result.getResultOrNull();
+		assertNotNull(liveList);
+		// list is sorted by last message timestamp
+		assertEquals(Arrays.asList(item2, item1), liveList);
+
+		// group 1 gets dissolved by creator
+		Event dissolvedEvent = new GroupDissolvedEvent(privateGroup1.getId());
+		viewModel.eventOccurred(dissolvedEvent);
+		result = getOrAwaitValue(viewModel.getGroupItems());
+		liveList = result.getResultOrNull();
+		assertNotNull(liveList);
+		assertEquals(2, liveList.size());
+		// assert that list update includes dissolved group item
+		for (GroupItem item : liveList) {
+			if (item.getId().equals(privateGroup1.getId())) {
+				assertTrue(item.isDissolved());
+			} else if (item.getId().equals(privateGroup2.getId())) {
+				assertFalse(item.isDissolved());
+			} else fail();
+		}
+	}
+
+	@Test
+	public void testLoadNumInvitations() throws Exception {
+		context.checking(new Expectations() {{
+			oneOf(lifecycleManager).waitForDatabase();
+			oneOf(groupInvitationManager).getInvitations();
+			will(returnValue(emptyList()));
+		}});
+		viewModel.loadNumInvitations();
+
+		int num = getOrAwaitValue(viewModel.getNumInvitations());
+		assertEquals(0, num);
+
+		PrivateGroup pg = context.mock(PrivateGroup.class);
+		Contact c = getContact();
+		GroupInvitationItem item = new GroupInvitationItem(pg, c);
+		context.checking(new Expectations() {{
+			oneOf(lifecycleManager).waitForDatabase();
+			oneOf(groupInvitationManager).getInvitations();
+			will(returnValue(singletonList(item)));
+		}});
+		viewModel.loadNumInvitations();
+
+		num = getOrAwaitValue(viewModel.getNumInvitations());
+		assertEquals(1, num);
+	}
+
+	private void expectLoadGroup(Transaction txn, PrivateGroup privateGroup,
+			AuthorInfo authorInfo, GroupCount groupCount, boolean dissolved)
+			throws DbException {
+		context.checking(new DbExpectations() {{
+			oneOf(contactManager)
+					.getAuthorInfo(txn, privateGroup.getCreator().getId());
+			will(returnValue(authorInfo));
+			oneOf(groupManager).getGroupCount(txn, privateGroup.getId());
+			will(returnValue(groupCount));
+			oneOf(groupManager).isDissolved(txn, privateGroup.getId());
+			will(returnValue(dissolved));
+		}});
+	}
+
+}

briar-android/src/test/java/org/briarproject/briar/android/viewmodel/LiveDataTestUtil.java

@@ -0,0 +1,36 @@
+/* Copyright 2019 Google LLC.
+   SPDX-License-Identifier: Apache-2.0
+   https://gist.github.com/JoseAlcerreca/1e9ee05dcdd6a6a6fa1cbfc125559bba
+   */
+
+package org.briarproject.briar.android.viewmodel;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import androidx.annotation.Nullable;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.Observer;
+
+public class LiveDataTestUtil {
+	public static <T> T getOrAwaitValue(final LiveData<T> liveData)
+			throws InterruptedException {
+		final Object[] data = new Object[1];
+		final CountDownLatch latch = new CountDownLatch(1);
+		Observer<T> observer = new Observer<T>() {
+			@Override
+			public void onChanged(@Nullable T o) {
+				data[0] = o;
+				latch.countDown();
+				liveData.removeObserver(this);
+			}
+		};
+		liveData.observeForever(observer);
+		// Don't wait indefinitely if the LiveData is not set.
+		if (!latch.await(2, TimeUnit.SECONDS)) {
+			throw new RuntimeException("LiveData value was never set.");
+		}
+		//noinspection unchecked
+		return (T) data[0];
+	}
+}