/sync-es6

How to write in sync (with only generator & yield ES6), based on waitfor-ES6

Primary LanguageJavaScript

About

The most native and simplest way to write-in-sync in NodeJS

This library is written purely in ES6 without any dependency

Still non-blocking node's event loop

Fully compatible with all other libraries (such as async)

NEW UPDATE: support Promise call (BETA - document pending) Example

Install

  • npm i sync-es6 --save

Usage

CALLBACK HELL:

main(callback) {
	async_function(arg1, (err, result1) => {
		another_async_function(arg2, (err, result2) => {
			return callback && callback(null, result1 + result2);
		});
	});
}

Step 0: make sure all of your callback functions will be callbacked as "function (err, result) {}" format

  • 1st param: error indicated (usually null)
  • 2nd param: real return value

Step 1: define wraper function as a generator function, and call inside functions in sync

function* writeSyncInside(args1, args2) { 
	let returnValue1 = yield [async_function, arg1];
	let returnValue2 = yield [another_async_function, arg2];

	return returnValue1 + returnValue2;
}

Step 2: CALL IT with sync

const _sync = require('sync-es6');

_sync(writeSyncInside /*,args1, args2, ... , callback*/);
// optional callback function at last argument, nice to have in case of error occurred

Sample code:

Syntax:

let iterator = _sync(runner,args1, args2, ... , finalcallback);

  • Parameters

    • runner (required): a generator function OR object {generator: function*, isTolerant: boolean}
      • isTolerant (optional, default "false"): if it's "true", when an error occurred in inside async function (when callback return (err)) the runner will not throw & break to finalcallback (if existed) and just return undefined
    • args (optional): input params for generator function
    • finalcallback (optional): catch error & final result for runner, if it's undefined the runner will throw() when error occurred

  • Return

    • iterator (optional): IT'S NOT final result value, just a iterator. Normally you wouldn't use it. It has .break(err) method when you want to break from runner function anytime.
iterator.break(err) // break exit from inside runner (generator) function.
  • Parameters
    • err (required): Error/String/... anything that's not null

Credit:

I write this library in thanks of Mr.Luciotato that looking into his code help me learn about generator function. I guess that because of he want the wait.for-es6 should be backward compatible with wait.for (ES5) so there something messy if you wall to call multiple async functions inside each others (with the "onComplete" event) OR maybe just I don't know how to use it properly. So I decide to seperate with a little modification to make it easier to use.