@@ -58,7 +58,14 @@ void checkLocalConnection(ConnectionOptions options) {
 InstanceAdminStubSettings.newBuilder()
 .setCredentialsProvider(NoCredentialsProvider.create())
 .setTransportChannelProvider(
-InstantiatingGrpcChannelProvider.newBuilder().setEndpoint(host).build());
+InstantiatingGrpcChannelProvider.newBuilder()
+.setEndpoint(host)
+.setChannelConfigurator(
+input -> {
+input.usePlaintext();
+return input;
+})
+.build());
 testEmulatorSettings
 .listInstanceConfigsSettings()
 .setSimpleTimeoutNoRetries(Duration.ofSeconds(10L));

@@ -26,7 +26,7 @@
 import java.util.Arrays;
 
 public class MockSpannerTestUtil {
-static final Statement SELECT1 = Statement.of("SELECT 1 AS COL1");
+public static final Statement SELECT1 = Statement.of("SELECT 1 AS COL1");
 private static final ResultSetMetadata SELECT1_METADATA =
 ResultSetMetadata.newBuilder()
 .setRowType(
@@ -41,7 +41,7 @@ public class MockSpannerTestUtil {
 .build())
 .build())
 .build();
-static final com.google.spanner.v1.ResultSet SELECT1_RESULTSET =
+public static final com.google.spanner.v1.ResultSet SELECT1_RESULTSET =
 com.google.spanner.v1.ResultSet.newBuilder()
 .addRows(
 ListValue.newBuilder()

@@ -0,0 +1,66 @@
+/*
+* Copyright 2021 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.connection;
+
+import static com.google.cloud.spanner.MockSpannerTestUtil.SELECT1;
+import static com.google.cloud.spanner.MockSpannerTestUtil.SELECT1_RESULTSET;
+
+import com.google.cloud.spanner.MockSpannerServiceImpl;
+import com.google.cloud.spanner.ResultSet;
+import io.grpc.Server;
+import io.grpc.netty.shaded.io.grpc.netty.NettyServerBuilder;
+import java.net.InetSocketAddress;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class LocalConnectionCheckerTest {
+
+private MockSpannerServiceImpl mockSpanner;
+private Server server;
+private InetSocketAddress address;
+
+@Before
+public void setUp() throws Exception {
+mockSpanner = new MockSpannerServiceImpl();
+mockSpanner.setAbortProbability(0.0D); // We don't want any unpredictable aborted transactions.
+address = new InetSocketAddress("localhost", 0);
+server = NettyServerBuilder.forAddress(address).addService(mockSpanner).build();
+server.start();
+}
+
+@After
+public void tearDown() throws Exception {
+server.shutdown();
+server.awaitTermination();
+}
+
+@Test
+public void localConnectionCheckerWorksWithMockSpanner() {
+final String uri =
+String.format(
+"cloudspanner://localhost:%d/projects/proj/instances/inst/databases/db?usePlainText=true",
+server.getPort());
+final ConnectionOptions connectionOptions = ConnectionOptions.newBuilder().setUri(uri).build();
+mockSpanner.putStatementResult(
+MockSpannerServiceImpl.StatementResult.query(SELECT1, SELECT1_RESULTSET));
+
+try (Connection connection = connectionOptions.getConnection();
+ResultSet resultSet = connection.executeQuery(SELECT1)) {
+while (resultSet.next()) {}
+}
+}
+}