chore(spanner): handle mock spanner logic

Author: harshachinta

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

@@ -30,6 +30,7 @@
 import com.google.common.base.Preconditions;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.spanner.v1.BeginTransactionRequest;
+import com.google.spanner.v1.RequestOptions;
 import com.google.spanner.v1.Transaction;
 import java.time.Clock;
 import java.time.Duration;
@@ -313,7 +314,9 @@ private void verifyBeginTransactionWithRWOnMultiplexedSession(String sessionName
             .setSession(sessionName)
             .setOptions(
                 SessionImpl.createReadWriteTransactionOptions(
-                    Options.fromTransactionOptions(), /* previousTransactionId = */ null));
+                    Options.fromTransactionOptions(), /* previousTransactionId = */ null))
+            .setRequestOptions(
+                RequestOptions.newBuilder().setTransactionTag("multiplexed-rw-background-begin-txn").build());
     final BeginTransactionRequest request = requestBuilder.build();
     final ApiFuture<Transaction> requestFuture;
     requestFuture =

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

@@ -159,6 +159,6 @@ boolean isMultiplexedSessionsEnabledForRW(Spanner spanner) {
   // This is due to the explicit BeginTransaction RPC that is executed once during multiplexed
   // session creation.
   protected int mayBeIncrementBeginTransactionRequestsCount(Spanner spanner, int count) {
-    return isMultiplexedSessionsEnabledForRW(spanner) ? count + 1 : count;
+    return isMultiplexedSessionsEnabledForRW(spanner) ? count + 0 : count;
   }
 }

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

@@ -1872,7 +1872,9 @@ private Transaction getTemporaryTransactionOrNull(TransactionSelector tx) {
   @Override
   public void beginTransaction(
       BeginTransactionRequest request, StreamObserver<Transaction> responseObserver) {
-    requests.add(request);
+    if (!request.getRequestOptions().getTransactionTag().equals("multiplexed-rw-background-begin-txn")) {
+      requests.add(request);
+    }
     Preconditions.checkNotNull(request.getSession());
     Session session = getSession(request.getSession());
     if (session == null) {

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

@@ -598,6 +598,7 @@ public void testMutationUsingWrite() {
 
     List<BeginTransactionRequest> beginTransactionRequests =
         mockSpanner.getRequestsOfType(BeginTransactionRequest.class);
+    assertEquals(2, beginTransactionRequests.size());
     assertEquals(
         mayBeIncrementBeginTransactionRequestsCount(spanner, /* count = */ 2),
         beginTransactionRequests.size());

google-cloud-spanner/src/test/java/com/google/cloud/spanner/connection/AbstractMockServerTest.java

@@ -334,6 +334,6 @@ boolean isMultiplexedSessionsEnabledForRW(Spanner spanner) {
   // This is due to the explicit BeginTransaction RPC that is executed once during multiplexed
   // session creation.
   protected int mayBeIncrementBeginTransactionRequestsCount(Spanner spanner, int count) {
-    return isMultiplexedSessionsEnabledForRW(spanner) ? count + 1 : count;
+    return isMultiplexedSessionsEnabledForRW(spanner) ? count + 0 : count;
   }
 }