fix: Improve test coverage for internal/wire folder. (#214)

* fix: Add a test for SinglePartitionPublisherBuilder.

* fix: Add a test for Versions.

* fix: Add a test for ChannelCache.

* fix: Improve ConnectedSubscriberImpl coverage.

* fix: Add a test for RoutingPublisher.

* fix: Add a test for PublisherBuilder.

* fix: Add test coverage for remaining builders.

* fix: Add licence headers.

google-cloud-pubsublite/src/main/java/com/google/cloud/pubsublite/internal/ChannelCache.java

@@ -16,21 +16,31 @@
 
 package com.google.cloud.pubsublite.internal;
 
+import com.google.common.annotations.VisibleForTesting;
 import io.grpc.Channel;
 import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
 
 /** A ChannelCache creates and stores default channels for use with api methods. */
 public class ChannelCache {
+  private final Function<String, ManagedChannel> channelFactory;
   private final ConcurrentHashMap<String, ManagedChannel> channels = new ConcurrentHashMap<>();
 
   public ChannelCache() {
+    this(ChannelCache::newChannel);
     Runtime.getRuntime().addShutdownHook(new Thread(this::onShutdown));
   }
 
-  private void onShutdown() {
+  @VisibleForTesting
+  ChannelCache(Function<String, ManagedChannel> channelFactory) {
+    this.channelFactory = channelFactory;
+  }
+
+  @VisibleForTesting
+  void onShutdown() {
     channels.forEachValue(
         channels.size(),
         channel -> {
@@ -43,10 +53,10 @@ private void onShutdown() {
   }
 
   public Channel get(String target) {
-    return channels.computeIfAbsent(target, this::newChannel);
+    return channels.computeIfAbsent(target, channelFactory);
   }
 
-  private ManagedChannel newChannel(String target) {
+  private static ManagedChannel newChannel(String target) {
     return ManagedChannelBuilder.forTarget(target).build();
   }
 }

google-cloud-pubsublite/src/main/java/com/google/cloud/pubsublite/internal/wire/SinglePartitionPublisherBuilder.java

@@ -39,8 +39,13 @@ public abstract class SinglePartitionPublisherBuilder {
   // Rarely set parameters.
   abstract PubsubContext context();
 
+  // For testing.
+  abstract PublisherBuilder.Builder underlyingBuilder();
+
   public static Builder newBuilder() {
-    return new AutoValue_SinglePartitionPublisherBuilder.Builder().setContext(PubsubContext.of());
+    return new AutoValue_SinglePartitionPublisherBuilder.Builder()
+        .setContext(PubsubContext.of())
+        .setUnderlyingBuilder(PublisherBuilder.builder());
   }
 
   @AutoValue.Builder
@@ -59,12 +64,16 @@ public abstract static class Builder {
     // Rarely set parameters.
     public abstract Builder setContext(PubsubContext context);
 
+    // For testing.
+    abstract Builder setUnderlyingBuilder(PublisherBuilder.Builder underlyingBuilder);
+
     abstract SinglePartitionPublisherBuilder autoBuild();
 
     public SinglePartitionPublisher build() throws StatusException {
       SinglePartitionPublisherBuilder builder = autoBuild();
       PublisherBuilder.Builder publisherBuilder =
-          PublisherBuilder.builder()
+          builder
+              .underlyingBuilder()
               .setTopic(builder.topic())
               .setPartition(builder.partition())
               .setContext(builder.context());

google-cloud-pubsublite/src/main/java/com/google/cloud/pubsublite/internal/wire/Versions.java

@@ -17,22 +17,32 @@
 package com.google.cloud.pubsublite.internal.wire;
 
 import com.google.api.gax.core.GaxProperties;
+import com.google.common.annotations.VisibleForTesting;
 
 /** The version number of this library. */
 final class Versions {
-  private Versions() {}
+  private final String versionString;
 
-  private static String[] GetVersionSplits() {
+  @VisibleForTesting
+  Versions(String versionString) {
+    this.versionString = versionString;
+  }
+
+  private Versions() {
+    this(GaxProperties.getLibraryVersion(Versions.class));
+  }
+
+  private String[] getVersionSplits() {
     try {
-      String versionString = GaxProperties.getLibraryVersion(Versions.class);
       return versionString.split("\\.");
     } catch (Exception e) {
       return new String[0];
     }
   }
 
-  private static int GetMajorVersion() {
-    String[] splits = GetVersionSplits();
+  @VisibleForTesting
+  int getMajorVersion() {
+    String[] splits = getVersionSplits();
     if (splits.length != 3) return 0;
     try {
       return Integer.parseInt(splits[0]);
@@ -41,8 +51,9 @@ private static int GetMajorVersion() {
     }
   }
 
-  private static int GetMinorVersion() {
-    String[] splits = GetVersionSplits();
+  @VisibleForTesting
+  int getMinorVersion() {
+    String[] splits = getVersionSplits();
     if (splits.length != 3) return 0;
     try {
       return Integer.parseInt(splits[1]);
@@ -51,7 +62,8 @@ private static int GetMinorVersion() {
     }
   }
 
+  private static final Versions VERSIONS = new Versions();
   // TODO: Do this using generation automation as opposed to maven packaging.
-  static final int MAJOR_VERSION = GetMajorVersion();
-  static final int MINOR_VERSION = GetMinorVersion();
+  static final int MAJOR_VERSION = VERSIONS.getMajorVersion();
+  static final int MINOR_VERSION = VERSIONS.getMinorVersion();
 }

google-cloud-pubsublite/src/test/java/com/google/cloud/pubsublite/internal/ChannelCacheTest.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * 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.google.cloud.pubsublite.internal;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.mockito.MockitoAnnotations.initMocks;
+
+import io.grpc.Channel;
+import io.grpc.ManagedChannel;
+import java.util.function.Function;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+import org.mockito.Mock;
+
+@RunWith(JUnit4.class)
+public class ChannelCacheTest {
+  @Mock ManagedChannel mockChannel;
+  @Mock Function<String, ManagedChannel> channelFactory;
+
+  @Before
+  public void setUp() {
+    initMocks(this);
+  }
+
+  @Test
+  public void reusesChannels() {
+    when(channelFactory.apply(any())).thenReturn(mockChannel);
+    ChannelCache cache = new ChannelCache(channelFactory);
+    Channel chan1 = cache.get("abc");
+    Channel chan2 = cache.get("abc");
+    assertThat(chan1).isEqualTo(chan2);
+    verify(channelFactory, times(1)).apply("abc");
+    when(mockChannel.shutdownNow()).thenReturn(mockChannel);
+    cache.onShutdown();
+    verify(mockChannel, times(1)).shutdownNow();
+  }
+}

google-cloud-pubsublite/src/test/java/com/google/cloud/pubsublite/internal/wire/AssignerBuilderTest.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * 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.google.cloud.pubsublite.internal.wire;
+
+import static org.mockito.Mockito.mock;
+
+import com.google.cloud.pubsublite.CloudRegion;
+import com.google.cloud.pubsublite.CloudZone;
+import com.google.cloud.pubsublite.ProjectNumber;
+import com.google.cloud.pubsublite.SubscriptionName;
+import com.google.cloud.pubsublite.SubscriptionPaths;
+import com.google.cloud.pubsublite.proto.PartitionAssignmentServiceGrpc;
+import io.grpc.Channel;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class AssignerBuilderTest {
+  @Test
+  public void testBuilder() throws Exception {
+    AssignerBuilder.newBuilder()
+        .setSubscriptionPath(
+            SubscriptionPaths.newBuilder()
+                .setZone(CloudZone.of(CloudRegion.of("us-central1"), 'a'))
+                .setProjectNumber(ProjectNumber.of(3))
+                .setSubscriptionName(SubscriptionName.of("abc"))
+                .build())
+        .setReceiver(mock(PartitionAssignmentReceiver.class))
+        .setAssignmentStub(PartitionAssignmentServiceGrpc.newStub(mock(Channel.class)))
+        .build();
+  }
+}

google-cloud-pubsublite/src/test/java/com/google/cloud/pubsublite/internal/wire/CommitterBuilderTest.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * 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.google.cloud.pubsublite.internal.wire;
+
+import static org.mockito.Mockito.mock;
+
+import com.google.cloud.pubsublite.CloudRegion;
+import com.google.cloud.pubsublite.CloudZone;
+import com.google.cloud.pubsublite.Partition;
+import com.google.cloud.pubsublite.ProjectNumber;
+import com.google.cloud.pubsublite.SubscriptionName;
+import com.google.cloud.pubsublite.SubscriptionPaths;
+import com.google.cloud.pubsublite.proto.CursorServiceGrpc;
+import com.google.cloud.pubsublite.proto.PartitionAssignmentServiceGrpc;
+import io.grpc.Channel;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class CommitterBuilderTest {
+  @Test
+  public void testBuilder() throws Exception {
+    CommitterBuilder.newBuilder()
+        .setSubscriptionPath(
+            SubscriptionPaths.newBuilder()
+                .setZone(CloudZone.of(CloudRegion.of("us-central1"), 'a'))
+                .setProjectNumber(ProjectNumber.of(3))
+                .setSubscriptionName(SubscriptionName.of("abc"))
+                .build())
+        .setPartition(Partition.of(987))
+        .setCursorStub(CursorServiceGrpc.newStub(mock(Channel.class)))
+        .build();
+  }
+}