chore: remove double client lib token header (#2681)

* chore: remove double client lib token header

Removes the double inclusion of the standard client lib token when no
custom client lib token has been set. Also reuses more of the standard
feature for setting the client lib token, instaed of appending the
standard token at the moment that we are creating the gRPC stub. This
should reduce the probability that anyone who might be using a custom
header or custom client in some way will get it wrong.

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* test: modify expected outcome to match the new behavior

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

README.md

@@ -50,20 +50,20 @@ If you are using Maven without the BOM, add this to your dependencies:
 If you are using Gradle 5.x or later, add this to your dependencies:
 
 ```Groovy
-implementation platform('com.google.cloud:libraries-bom:26.24.0')
+implementation platform('com.google.cloud:libraries-bom:26.25.0')
 
 implementation 'com.google.cloud:google-cloud-spanner'
 ```
 If you are using Gradle without BOM, add this to your dependencies:
 
 ```Groovy
-implementation 'com.google.cloud:google-cloud-spanner:6.50.1'
+implementation 'com.google.cloud:google-cloud-spanner:6.51.0'
 ```
 
 If you are using SBT, add this to your dependencies:
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.50.1"
+libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.51.0"
 ```
 <!-- {x-version-update-end} -->
 
@@ -432,7 +432,7 @@ Java is a registered trademark of Oracle and/or its affiliates.
 [kokoro-badge-link-5]: http://storage.googleapis.com/cloud-devrel-public/java/badges/java-spanner/java11.html
 [stability-image]: https://img.shields.io/badge/stability-stable-green
 [maven-version-image]: https://img.shields.io/maven-central/v/com.google.cloud/google-cloud-spanner.svg
-[maven-version-link]: https://central.sonatype.com/artifact/com.google.cloud/google-cloud-spanner/6.50.1
+[maven-version-link]: https://central.sonatype.com/artifact/com.google.cloud/google-cloud-spanner/6.51.0
 [authentication]: https://github.com/googleapis/google-cloud-java#authentication
 [auth-scopes]: https://developers.google.com/identity/protocols/oauth2/scopes
 [predefined-iam-roles]: https://cloud.google.com/iam/docs/understanding-roles#predefined_roles

google-cloud-spanner/src/main/java/com/google/cloud/spanner/SpannerOptions.java

@@ -17,6 +17,7 @@
 package com.google.cloud.spanner;
 
 import com.google.api.core.ApiFunction;
+import com.google.api.core.InternalApi;
 import com.google.api.gax.core.ExecutorProvider;
 import com.google.api.gax.grpc.GrpcCallContext;
 import com.google.api.gax.grpc.GrpcInterceptorProvider;
@@ -686,10 +687,10 @@ public static class Builder
     private final ImmutableSet<String> allowedClientLibTokens =
         ImmutableSet.of(
             ServiceOptions.getGoogApiClientLibName(),
-            JDBC_API_CLIENT_LIB_TOKEN,
-            HIBERNATE_API_CLIENT_LIB_TOKEN,
-            LIQUIBASE_API_CLIENT_LIB_TOKEN,
-            PG_ADAPTER_CLIENT_LIB_TOKEN);
+            createCustomClientLibToken(JDBC_API_CLIENT_LIB_TOKEN),
+            createCustomClientLibToken(HIBERNATE_API_CLIENT_LIB_TOKEN),
+            createCustomClientLibToken(LIQUIBASE_API_CLIENT_LIB_TOKEN),
+            createCustomClientLibToken(PG_ADAPTER_CLIENT_LIB_TOKEN));
     private TransportChannelProvider channelProvider;
 
     @SuppressWarnings("rawtypes")
@@ -725,6 +726,10 @@ public static class Builder
     private String emulatorHost = System.getenv("SPANNER_EMULATOR_HOST");
     private boolean leaderAwareRoutingEnabled = true;
 
+    private static String createCustomClientLibToken(String token) {
+      return token + " " + ServiceOptions.getGoogApiClientLibName();
+    }
+
     private Builder() {
       // Manually set retry and polling settings that work.
       OperationTimedPollAlgorithm longRunningPollingAlgorithm =
@@ -795,6 +800,13 @@ protected Set<String> getAllowedClientLibTokens() {
       return allowedClientLibTokens;
     }
 
+    @InternalApi
+    @Override
+    public SpannerOptions.Builder setClientLibToken(String clientLibToken) {
+      return super.setClientLibToken(
+          clientLibToken + " " + ServiceOptions.getGoogApiClientLibName());
+    }
+
     /**
      * Sets the {@code ChannelProvider}. {@link GapicSpannerRpc} would create a default one if none
      * is provided.

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

@@ -55,7 +55,6 @@
 import com.google.api.pathtemplate.PathTemplate;
 import com.google.cloud.RetryHelper;
 import com.google.cloud.RetryHelper.RetryHelperException;
-import com.google.cloud.ServiceOptions;
 import com.google.cloud.grpc.GcpManagedChannelBuilder;
 import com.google.cloud.grpc.GcpManagedChannelOptions;
 import com.google.cloud.grpc.GcpManagedChannelOptions.GcpMetricsOptions;
@@ -297,8 +296,7 @@ public GapicSpannerRpc(final SpannerOptions options) {
     ApiClientHeaderProvider internalHeaderProvider =
         internalHeaderProviderBuilder
             .setClientLibToken(
-                options.getClientLibToken() + " " + ServiceOptions.getGoogApiClientLibName(),
-                GaxProperties.getLibraryVersion(options.getClass()))
+                options.getClientLibToken(), GaxProperties.getLibraryVersion(options.getClass()))
             .setTransportToken(
                 GaxGrpcProperties.getGrpcTokenName(), GaxGrpcProperties.getGrpcVersion())
             .build();

google-cloud-spanner/src/test/java/com/google/cloud/spanner/SpannerOptionsTest.java

@@ -516,23 +516,25 @@ public void testSetClientLibToken() {
             .setCredentials(NoCredentials.getInstance())
             .setClientLibToken(jdbcToken)
             .build();
-    assertThat(options.getClientLibToken()).isEqualTo(jdbcToken);
+    // Verify that the client lib token that will actually be used contains both the JDBC token and
+    // the standard Java client library token ('gccl').
+    assertEquals("sp-jdbc gccl", options.getClientLibToken());
 
     options =
         SpannerOptions.newBuilder()
             .setProjectId("some-project")
             .setCredentials(NoCredentials.getInstance())
             .setClientLibToken(hibernateToken)
             .build();
-    assertThat(options.getClientLibToken()).isEqualTo(hibernateToken);
+    assertEquals("sp-hib gccl", options.getClientLibToken());
 
     options =
         SpannerOptions.newBuilder()
             .setProjectId("some-project")
             .setCredentials(NoCredentials.getInstance())
             .setClientLibToken(pgAdapterToken)
             .build();
-    assertEquals(options.getClientLibToken(), pgAdapterToken);
+    assertEquals("pg-adapter gccl", options.getClientLibToken());
 
     options =
         SpannerOptions.newBuilder()

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

@@ -583,6 +583,35 @@ public void testRouteToLeaderHeaderWithLeaderAwareRoutingDisabled() {
     assertFalse(isRouteToLeader);
   }
 
+  @Test
+  public void testClientLibToken() {
+    SpannerOptions options = createSpannerOptions();
+    try (Spanner spanner = options.getService()) {
+      DatabaseClient databaseClient =
+          spanner.getDatabaseClient(DatabaseId.of("[PROJECT]", "[INSTANCE]", "[DATABASE]"));
+      TransactionRunner runner = databaseClient.readWriteTransaction();
+      runner.run(transaction -> transaction.executeUpdate(UPDATE_FOO_STATEMENT));
+    }
+    Key<String> key = Key.of("x-goog-api-client", Metadata.ASCII_STRING_MARSHALLER);
+    assertTrue(lastSeenHeaders.containsKey(key));
+    assertTrue(
+        lastSeenHeaders.get(key),
+        Objects.requireNonNull(lastSeenHeaders.get(key))
+            .contains(ServiceOptions.getGoogApiClientLibName() + "/"));
+    // Check that the default header value is only included once in the header.
+    // We do this by splitting the entire header by the default header value. The resulting array
+    // should have 2 elements.
+    assertEquals(
+        lastSeenHeaders.get(key),
+        2,
+        Objects.requireNonNull(lastSeenHeaders.get(key))
+            .split(ServiceOptions.getGoogApiClientLibName())
+            .length);
+    assertTrue(
+        lastSeenHeaders.get(key),
+        Objects.requireNonNull(lastSeenHeaders.get(key)).contains("gl-java/"));
+  }
+
   @Test
   public void testCustomClientLibToken_alsoContainsDefaultToken() {
     SpannerOptions options =
@@ -602,6 +631,9 @@ public void testCustomClientLibToken_alsoContainsDefaultToken() {
         lastSeenHeaders.get(key),
         Objects.requireNonNull(lastSeenHeaders.get(key))
             .contains(ServiceOptions.getGoogApiClientLibName() + "/"));
+    assertTrue(
+        lastSeenHeaders.get(key),
+        Objects.requireNonNull(lastSeenHeaders.get(key)).contains("gl-java/"));
   }
 
   private SpannerOptions createSpannerOptions() {