add optional debugging output

package.json

@@ -30,6 +30,7 @@
     "sinon": "~1.17.3"
   },
   "dependencies": {
+    "debug": "~2.2.0",
     "elasticsearch": "~11.0.1",
     "lodash": "~4.11.1",
     "moment": "~2.10.6",

src/helpers/logger.js

@@ -0,0 +1,5 @@
+import debugging from 'debug';
+
+export default function logger(type) {
+  return debugging(type);
+}

src/index.js

@@ -1,10 +1,13 @@
 import events from 'events';
 import createClient from './helpers/es_client';
 import indexTimestamp from './helpers/index_timestamp';
+import logger from './helpers/logger';
 import Job from './job.js';
 import Worker from './worker.js';
 import { omit } from 'lodash';
 
+const debug = logger('queue');
+
 export default class Elastique extends events.EventEmitter {
   constructor(index, options = {}) {
     if (!index) throw new Error('Must specify an index to write to');
@@ -21,12 +24,14 @@ export default class Elastique extends events.EventEmitter {
   }
 
   _initTasks() {
-
     var initTasks = [
       this.client.ping({ timeout: 3000 }),
     ];
 
-    return Promise.all(initTasks);
+    return Promise.all(initTasks).catch((err) => {
+      debug('Initialization failed', err);
+      throw err;
+    });
   }
 
   add(type, payload, opts = {}) {

src/job.js

@@ -1,8 +1,11 @@
 import events from 'events';
 import { isPlainObject } from 'lodash';
+import logger from './helpers/logger';
 import { JOB_STATUS_PENDING } from './helpers/constants';
 import createIndex from './helpers/create_index';
 
+const debug = logger('job');
+
 export default class Job extends events.EventEmitter {
   constructor(client, index, type, payload, timeout = 10000) {
     if (typeof type !== 'string') throw new Error('Type must be a string');
@@ -38,9 +41,11 @@ export default class Job extends events.EventEmitter {
           type: doc._type,
           version: doc._version,
         };
+        debug('Job created', this.document);
       });
     })
     .catch((err) => {
+      debug('Job creation failed', err);
       this.emit('error', err);
       throw err;
     });