make the mock client get method async

and update worker tests to use async value

test/fixtures/elasticsearch.js

@@ -45,14 +45,14 @@ Client.prototype.get = function (params = {}, source = {}) {
     status: 'pending'
   }, source);
 
-  return {
+  return Promise.resolve({
     _index: params.index || 'index',
     _type: params.type || DEFAULT_SETTING_DOCTYPE,
     _id: params.id || 'AVRPRLnlp7Ur1SZXfT-T',
     _version: params.version || 1,
     found: true,
     _source: _source
-  };
+  });
 };
 
 Client.prototype.search = function (params = {}, count = 5, source = {}) {

test/src/worker.js

@@ -285,10 +285,13 @@ describe('Worker class', function () {
         id: 12345,
         version: 3
       };
-      job = mockQueue.client.get(params);
+      return mockQueue.client.get(params)
+      .then((jobDoc) => {
+        job = jobDoc;
         worker = new Worker(mockQueue, 'test', noop);
         updateSpy = sinon.spy(mockQueue.client, 'update');
       });
+    });
 
     afterEach(() => {
       clock.restore();
@@ -364,16 +367,18 @@ describe('Worker class', function () {
       anchorMoment = moment(anchor);
       clock = sinon.useFakeTimers(anchorMoment.valueOf());
 
-      job = mockQueue.client.get();
+      return mockQueue.client.get()
+      .then((jobDoc) => {
+        job = jobDoc;
         worker = new Worker(mockQueue, 'test', noop);
         updateSpy = sinon.spy(mockQueue.client, 'update');
       });
+    });
 
     afterEach(() => {
       clock.restore();
     });
 
-
     it('should use version on update', function () {
       worker._failJob(job);
       const query = updateSpy.firstCall.args[0];
@@ -427,9 +432,13 @@ describe('Worker class', function () {
       payload = {
         value: random(0, 100, true)
       };
-      job = mockQueue.client.get({}, { payload });
+
+      return mockQueue.client.get({}, { payload })
+      .then((jobDoc) => {
+        job = jobDoc;
         updateSpy = sinon.spy(mockQueue.client, 'update');
       });
+    });
 
     it('should call the workerFn with the payload', function (done) {
       const workerFn = function (jobPayload) {