add tests

Author: rahul2393

google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/ChannelFinderServerFactory.java

@@ -22,8 +22,8 @@
  * Factory for creating and caching server connections for location-aware routing.
  *
  * <p>Implementations are expected to cache {@link ChannelFinderServer} instances such that repeated
- * calls with the same address return the same instance. This allows the {@link
- * com.google.cloud.spanner.spi.v1.KeyRangeCache} to efficiently manage server references.
+ * calls with the same address return the same instance. This allows routing components to
+ * efficiently manage server references.
  *
  * <p>Implementations must be thread-safe. Multiple threads may concurrently call {@link
  * #create(String)} with different addresses.

google-cloud-spanner/src/main/java/com/google/cloud/spanner/spi/v1/GrpcChannelFinderServerFactory.java

@@ -147,7 +147,12 @@ static class GrpcChannelFinderServer implements ChannelFinderServer {
      */
     GrpcChannelFinderServer(String address, TransportChannelProvider provider) throws IOException {
       this.address = address;
-      GrpcTransportChannel transportChannel = (GrpcTransportChannel) provider.getTransportChannel();
+      TransportChannelProvider readyProvider = provider;
+      if (provider.needsHeaders()) {
+        readyProvider = provider.withHeaders(java.util.Collections.emptyMap());
+      }
+      GrpcTransportChannel transportChannel =
+          (GrpcTransportChannel) readyProvider.getTransportChannel();
       this.channel = (ManagedChannel) transportChannel.getChannel();
     }
 
@@ -173,9 +178,15 @@ public boolean isHealthy() {
       if (channel.isShutdown() || channel.isTerminated()) {
         return false;
       }
-      // Check connectivity state without triggering a connection attempt
-      ConnectivityState state = channel.getState(false);
-      return state != ConnectivityState.SHUTDOWN && state != ConnectivityState.TRANSIENT_FAILURE;
+      // Check connectivity state without triggering a connection attempt.
+      // Some channel implementations don't support getState(), in which case
+      // we assume the channel is healthy if it's not shutdown/terminated.
+      try {
+        ConnectivityState state = channel.getState(false);
+        return state != ConnectivityState.SHUTDOWN && state != ConnectivityState.TRANSIENT_FAILURE;
+      } catch (UnsupportedOperationException e) {
+        return true;
+      }
     }
 
     @Override

google-cloud-spanner/src/test/java/com/google/cloud/spanner/spi/v1/GrpcChannelFinderServerFactoryTest.java

@@ -0,0 +1,119 @@
+/*
+ * Copyright 2026 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.spanner.spi.v1;
+
+import static com.google.common.truth.Truth.assertThat;
+import static org.junit.Assert.assertThrows;
+
+import com.google.api.gax.grpc.InstantiatingGrpcChannelProvider;
+import com.google.cloud.spanner.SpannerException;
+import io.grpc.ManagedChannelBuilder;
+import org.junit.Test;
+
+public class GrpcChannelFinderServerFactoryTest {
+
+  private static InstantiatingGrpcChannelProvider createProvider(String endpoint) {
+    return InstantiatingGrpcChannelProvider.newBuilder()
+        .setEndpoint(endpoint)
+        .setChannelConfigurator(ManagedChannelBuilder::usePlaintext)
+        .build();
+  }
+
+  @Test
+  public void defaultServerIsCached() throws Exception {
+    GrpcChannelFinderServerFactory factory =
+        new GrpcChannelFinderServerFactory(createProvider("localhost:1234"));
+    try {
+      ChannelFinderServer defaultServer = factory.defaultServer();
+      ChannelFinderServer server = factory.create(defaultServer.getAddress());
+      assertThat(server).isSameInstanceAs(defaultServer);
+    } finally {
+      factory.shutdown();
+    }
+  }
+
+  @Test
+  public void createCachesPerAddress() throws Exception {
+    GrpcChannelFinderServerFactory factory =
+        new GrpcChannelFinderServerFactory(createProvider("localhost:1234"));
+    try {
+      ChannelFinderServer first = factory.create("localhost:1111");
+      ChannelFinderServer second = factory.create("localhost:1111");
+      ChannelFinderServer third = factory.create("localhost:2222");
+
+      assertThat(second).isSameInstanceAs(first);
+      assertThat(third).isNotSameInstanceAs(first);
+    } finally {
+      factory.shutdown();
+    }
+  }
+
+  @Test
+  public void evictRemovesNonDefaultServer() throws Exception {
+    GrpcChannelFinderServerFactory factory =
+        new GrpcChannelFinderServerFactory(createProvider("localhost:1234"));
+    try {
+      ChannelFinderServer first = factory.create("localhost:1111");
+      factory.evict("localhost:1111");
+      ChannelFinderServer second = factory.create("localhost:1111");
+
+      assertThat(second).isNotSameInstanceAs(first);
+    } finally {
+      factory.shutdown();
+    }
+  }
+
+  @Test
+  public void evictIgnoresDefaultServer() throws Exception {
+    GrpcChannelFinderServerFactory factory =
+        new GrpcChannelFinderServerFactory(createProvider("localhost:1234"));
+    try {
+      ChannelFinderServer defaultServer = factory.defaultServer();
+      factory.evict(defaultServer.getAddress());
+      ChannelFinderServer server = factory.create(defaultServer.getAddress());
+
+      assertThat(server).isSameInstanceAs(defaultServer);
+    } finally {
+      factory.shutdown();
+    }
+  }
+
+  @Test
+  public void shutdownPreventsNewServers() throws Exception {
+    GrpcChannelFinderServerFactory factory =
+        new GrpcChannelFinderServerFactory(createProvider("localhost:1234"));
+    factory.shutdown();
+
+    assertThrows(SpannerException.class, () -> factory.create("localhost:1111"));
+    assertThat(factory.defaultServer().getChannel().isShutdown()).isTrue();
+  }
+
+  @Test
+  public void healthReflectsChannelShutdown() throws Exception {
+    GrpcChannelFinderServerFactory factory =
+        new GrpcChannelFinderServerFactory(createProvider("localhost:1234"));
+    try {
+      ChannelFinderServer server = factory.create("localhost:1111");
+      assertThat(server.isHealthy()).isTrue();
+
+      server.getChannel().shutdownNow();
+      assertThat(server.isHealthy()).isFalse();
+    } finally {
+      factory.shutdown();
+    }
+  }
+}