promise-waterfall

Promise-waterfall

Promise-waterfall extends promise utilities with sequential flow control like async.waterfall.

Since Promise.all(promiseArr) || Promise.spread(promiseArr) execs promises simultaneously, each of the functions in the promiseArr cannot depend on another, and if you want promises execute in order or some of the promises need the resolved value of another, this library is for you.

Installation

npm install promise-waterfall

Usage

var waterfall = require("promise-waterfall");
var func1 = function(){
        // return a promise
    },
    func2 = function(res1){
        // optionally use res1 
        // which is resolved from func1 
        // and return a promise
    },
    func3 = function(res2){
        // like func2
    },
    promiseSequence = [func1, func2, func3];
    
waterfall(promiseSequence) 
    // the promiseSequence will executes sequentially
    // just like func1().then(func2).then(func3)
    .then(function(res){
        // use res
    })
    .catch(function(err){
        // deal with error
    });

See test cases in /tests for full examples.

Development

Test

run npm test or make test

Changelog

• v0.1 (Thanks to @stevenvachon)
  • Return a promise(fulfilled when returned normally or rejected when error occurs) in whatever condition;
  • Compatible with all libraries conforming to Promises/A+ spec;
  • Dropped client support
• v0.0.1
  • First release

Thanks