fix: Don't route to leader for single-use transactions in Client#execute_query

google-cloud-spanner/lib/google/cloud/spanner/client.rb

@@ -484,7 +484,7 @@ def execute_query sql, params: nil, types: nil, single_use: nil,
           request_options = Convert.to_request_options request_options,
                                                        tag_type: :request_tag
           single_use_tx = single_use_transaction single_use
-          route_to_leader = LARHeaders.execute_query true
+          route_to_leader = LARHeaders.execute_query false
           results = nil
           @pool.with_session do |session|
             results = session.execute_query \

google-cloud-spanner/test/google/cloud/spanner/leader_aware_routing/client/execute_query_test.rb

@@ -60,13 +60,13 @@
     mock.verify
   end
 
-  it "sends header x-goog-spanner-route-to-leader when LAR is enabled" do
+  it "sends header x-goog-spanner-route-to-leader with true for queries without single_use when LAR is enabled" do
     mock = Minitest::Mock.new
     mock.expect :create_session, session_grpc do |request, gapic_options|
       gapic_options.metadata["x-goog-spanner-route-to-leader"] == 'true'
     end    
     mock.expect :execute_streaming_sql, results_enum do |request, gapic_options|
-      gapic_options.metadata["x-goog-spanner-route-to-leader"] == 'true'
+      gapic_options.metadata["x-goog-spanner-route-to-leader"] == 'false'
     end
     spanner.service.mocked_service = mock
 
@@ -75,4 +75,53 @@
 
     mock.verify
   end
+
+  it "sends header x-goog-spanner-route-to-leader with false for queries with single_use strong option when LAR is enabled" do
+    mock = Minitest::Mock.new
+    mock.expect :create_session, session_grpc do |request, gapic_options|
+      gapic_options.metadata["x-goog-spanner-route-to-leader"] == 'true'
+    end
+    mock.expect :execute_streaming_sql, results_enum do |request, gapic_options|
+      gapic_options.metadata["x-goog-spanner-route-to-leader"] == 'false'
+    end
+    spanner.service.mocked_service = mock
+
+    spanner.service.enable_leader_aware_routing = true
+    results = client.execute_query "SELECT 1", single_use: { strong: true }
+
+    mock.verify
+  end
+
+  it "sends header x-goog-spanner-route-to-leader with false for queries with single_use staleness option when LAR is enabled" do
+    mock = Minitest::Mock.new
+    mock.expect :create_session, session_grpc do |request, gapic_options|
+      gapic_options.metadata["x-goog-spanner-route-to-leader"] == 'true'
+    end
+    mock.expect :execute_streaming_sql, results_enum do |request, gapic_options|
+      gapic_options.metadata["x-goog-spanner-route-to-leader"] == 'false'
+    end
+    spanner.service.mocked_service = mock
+
+    spanner.service.enable_leader_aware_routing = true
+    results = client.execute_query "SELECT 1", single_use: { staleness: 60 }
+
+    mock.verify
+  end
+
+  it "sends header x-goog-spanner-route-to-leader with false for queries with single_use timestamp option when LAR is enabled" do
+    mock = Minitest::Mock.new
+    mock.expect :create_session, session_grpc do |request, gapic_options|
+      gapic_options.metadata["x-goog-spanner-route-to-leader"] == 'true'
+    end
+    mock.expect :execute_streaming_sql, results_enum do |request, gapic_options|
+      gapic_options.metadata["x-goog-spanner-route-to-leader"] == 'false'
+    end
+    spanner.service.mocked_service = mock
+
+    spanner.service.enable_leader_aware_routing = true
+    timestamp = Time.now - 60
+    results = client.execute_query "SELECT 1", single_use: { timestamp: timestamp }
+
+    mock.verify
+  end
 end