feat: grpc keep alive settings

src/index.ts

@@ -305,6 +305,9 @@ class Spanner extends GrpcService {
         libName: 'gccl',
         libVersion: require('../../package.json').version,
         scopes,
+        // Add grpc keep alive setting
+        'grpc.keepalive_time_ms': 30000,
+        'grpc.keepalive_timeout_ms': 10000,
         // Enable grpc-gcp support
         'grpc.callInvocationTransformer': grpcGcp.gcpCallInvocationTransformer,
         'grpc.channelFactoryOverride': grpcGcp.gcpChannelFactoryOverride,

test/index.ts

@@ -204,6 +204,8 @@ describe('Spanner', () => {
       libVersion: require('../../package.json').version,
       scopes: [],
       grpc,
+      'grpc.keepalive_time_ms': 30000,
+      'grpc.keepalive_timeout_ms': 10000,
       'grpc.callInvocationTransformer':
         fakeGrpcGcp().gcpCallInvocationTransformer,
       'grpc.channelFactoryOverride': fakeGrpcGcp().gcpChannelFactoryOverride,
@@ -251,6 +253,24 @@ describe('Spanner', () => {
       );
     });
 
+    it('should override grpc settings', () => {
+      const keepaliveOptions = {
+        'grpc.keepalive_time_ms': 300,
+        'grpc.keepalive_timeout_ms': 100,
+      };
+      const options = extend({}, OPTIONS, keepaliveOptions);
+      const spanner = new Spanner(options);
+      const expectedOptions = Object.assign(
+        {},
+        EXPECTED_OPTIONS,
+        keepaliveOptions
+      );
+      assert.deepStrictEqual(
+        getFake(spanner.auth).calledWith_[0],
+        expectedOptions
+      );
+    });
+
     it('should inherit from GrpcService', () => {
       assert(spanner instanceof FakeGrpcService);