fix: unhandled exceptions from gax (#2338)

Author: alkatrivedi

src/index.ts

@@ -1523,8 +1523,12 @@ class Spanner extends GrpcService {
  return;
  }
  const clientName = config.client;
- if (!this.clients_.has(clientName)) {
- this.clients_.set(clientName, new v1[clientName](this.options));
+ try {
+ if (!this.clients_.has(clientName)) {
+ this.clients_.set(clientName, new v1[clientName](this.options));
+ }
+ } catch (err) {
+ callback(err, null);
  }
  const gaxClient = this.clients_.get(clientName)!;
  let reqOpts = extend(true, {}, config.reqOpts);

test/index.ts

@@ -2000,6 +2000,22 @@ describe('Spanner', () => {
  });
  });
 
+ it('should be able to catch any error from google-gax-library', done => {
+ const error = new Error('Error.');
+
+ fakeV1[CONFIG.client] = class {
+ constructor(options) {
+ assert.strictEqual(options, spanner.options);
+ throw error;
+ }
+ };
+
+ spanner.prepareGapicRequest_(CONFIG, err => {
+ assert.strictEqual(err, error);
+ done();
+ });
+ });
+
  it('should create and cache a gapic client', done => {
  fakeV1[CONFIG.client] = class {
  constructor(options) {