rename create client, fix client instance test

src/helpers/es_client.js

@@ -3,7 +3,8 @@ import elasticsearch from 'elasticsearch';
 export default function createClient(options) {
   let client;
 
-  if (options instanceof elasticsearch.Client) {
+  // if there's a transport property, assume it's a client instance
+  if (isClient(options)) {
     client = options;
   } else {
     client = new elasticsearch.Client(options);
@@ -11,3 +12,7 @@ export default function createClient(options) {
 
   return client;
 };
+
+export function isClient(client) {
+  return !!client.transport;
+}

test/src/helpers/es_client.js

@@ -2,24 +2,25 @@ import expect from 'expect.js';
 import proxyquire from 'proxyquire';
 import * as elasticsearchMock from '../../fixtures/elasticsearch';
 
-const createClient = proxyquire.noPreserveCache()('../../../lib/helpers/create_client', {
+const module = proxyquire.noPreserveCache()('../../../lib/helpers/es_client', {
   elasticsearch: elasticsearchMock
 });
 
+const createClient = module.default;
+const { isClient } = module;
+
 describe('Create client helper', function () {
   it('should have a client', function () {
     const options = {
       host: 'http://localhost:9200'
     };
     const client = createClient(options);
-
+    expect(isClient(client)).to.be.ok();
-    expect(client).to.be.a(elasticsearchMock.Client);
   });
 
   it('should use passed in instance', function () {
     const clientInstance = new elasticsearchMock.Client();
     const client = createClient(clientInstance);
-
     expect(client).to.equal(clientInstance);
   });
 });