Promisifying Azure Table Storage queries in Node

app.js

/**
 * ATS Promisfy node demo
 * Steve Hobbs, July 2015
 * See associated package.json for package install
 */

var chalk = require('chalk');
var azure = require('azure-storage');
var deferred = require('deferred');

var config = {	
	accountName: '**',
	key: '**'	
};

// Create a promisify method that takes the original ATS method and turns it into
// one that returns a promise object.
var promisify = function(fn, target) {
	
	return function() {	
		
		var d = deferred();						
		var args = Array.prototype.slice.call(arguments, 0, arguments.length);
		
		args.push(function(err, result) {
			if (err)
				d.reject(err);
			else
				d.resolve(result);
		});
		
		fn.apply(target, args);	
	
		return d.promise;
	};
};

console.log(chalk.yellow('Loading Azure entities..'));

// Create table service
var tableService = azure.createTableService(config.accountName, config.key);

// Promisify the 'retrieveEntity' method
var retrieveEntity = promisify(tableService.retrieveEntity, tableService);

// Promisify the 'createTable' method
var createTable = promisify(tableService.createTableIfNotExists, tableService);

// Use the promisified methods
retrieveEntity('posts', 'general', 'AAAA7216583744299')(function(result) {
	console.log(result);
});

createTable('testTable').done(function(result) { 
	console.log('Table created') 
});

package.json

{
  "name": "azure-promisify",
  "version": "1.0.0",
  "description": "",
  "main": "app.js",
  "scripts": {
    "start": "node app.js"
  },
  "author": "Steve Hobbs <[email protected]> (http://stevescodingblog.co.uk)",
  "license": "ISC",
  "dependencies": {
    "azure": "^0.10.6",
    "azure-storage": "^0.4.5",
    "chalk": "^1.0.0",
    "deferred": "^0.7.2"
  }
}