Contextual Promise Chain JS

contextualpromisechain.js

//    allows you to use contexts within promise chains.

//    works best w/ KeyStore where you use your context as your keystore context name / id.
//		KeyStore.js | a globally reusable value / reference storage
//		https://gist.github.com/servercharlie/f5b104ceb0bb559e6281b040e6d875e4
          
//    use your own contexts, or use uuid's (like in the provided example) 
//		SimpleUUID.js | an expertly refined generator & validator for UUIDv4.
//		https://gist.github.com/servercharlie/70638dd74bec7b52223ef9794b47f83c

var ContextualPromiseChain = function(_context, _promises){
	return new Promise(function (resolve, reject) {
		function recurse(){
			if(_promises.length >= 1){
				let _currentPromise = _promises.shift();
				_currentPromise(_context)
					.then(()=>{recurse()}, (reason)=>{reject(reason)});
			}else{
				resolve();
			}
		}
		recurse();
	});
};

// usage:
// tested w/ gulp, just remove the gulp parts if you don't want it.

gulp.task(`chain`, () => {	

	var p1 = function(_context){return new Promise(function (resolve, reject) {
		console.log("Context:", _context);
		setTimeout(function(){
			resolve();
		}, 3000);
	})};
	var p2 = function(_context){return new Promise(function (resolve, reject) {
		console.log("Context:", _context);
		setTimeout(function(){
			resolve();
		}, 5000);
	})};
	
	return ContextualPromiseChain(
		uuidv4(),
		[p1, p2]
	);
	
});