SeqProm

Repo for Sequential Promises project

Installation

npm install seq-prom --save

Options

Option	Type	Description	Default	Required?
list	Array	List of items to iterate through		Yes
cb	Function	Function called when time to process next item		Yes
batchSize	Integer	Size of the batch, or if using stream mode, how many streams to use	1	No
errorCB	Function	Called when there is an error, with the item and reason for error		No
finalCB	Function	Called when all is done. Passes in a list of errors, and any items, passed to the resolve method		No
useStream	Boolean	Will switch to stream mode, which meaning multiple queues are created with the list	false	No
autoStart	Boolean	Instead of having to call .start() will do this for you	false	No

Usage

Basic Example

const SeqProm = require("seq-prom");

let seqProm = SeqProm({
  list: [1, 2, 3],
  cb  (item, resolve, reject) {
    console.log(`Item [${item}] called!`);
    setTimeout(function () {
      if (item === 3) {
        return reject("Not sure about this!");
      } else {
        return resolve();
      }
    }, item * 1000);
  },
  errorCB (item, reason) {
    console.error(`Item [${item}] failed with error: ${reason}`);
  },
  finalCB (){
    console.log("All done!");
  }
});

seqProm.start();

Other Options

const SeqProm = require("seq-prom");

SeqProm({
  list: [1, 2, 3, 4],
  autoStart: true,
  useStream : true,
  batchSize : 2,
  cb  (item, resolve, reject) {
    console.log(`Item [${item}] called!`);
    setTimeout(function () {
      if (item === 3) {
        return reject("Not sure about this!");
      } else {
        return resolve(item);
      }
    }, item * 1000);
  },
  errorCB (item, reason) {
    console.error(`Item [${item}] failed with error: ${reason}`);
  },
  finalCB (errors, responses){
    console.log("All done!");
    console.dir(errors);
    console.dir(responses);
  }
})
.promise
.then(function(){
  console.log("Called after all is said and done");
});

Functions

cb

Argument	Description
item	Item from the list
resolver	The resolve function from the promise
rejecter	The reject function from the promise
self	this passed through. Can call .stop() on this
threadId	If in stream mode, then this will be the threadId

errorCB

Argument	Description
item	Item from the list
reason	Reason for the error, either from the reject method or a caught error

finalCB

Argument	Description
error	List of errors that have occured
response	List of items passed back to the resolve function

Promise Response

const SeqProm = require("seq-prom");

SeqProm({
  list: [1, 2, 3],
  autoStart : true,
  cb  (item, resolve, reject) {
    console.log(`Item [${item}] called!`);
    setTimeout(function () {
      if (item === 3) {
        return reject("Not sure about this!");
      } else {
        return resolve(item);
      }
    }, item * 1000);
  },
  errorCB (item, reason) {
    console.error(`Item [${item}] failed with error: ${reason}`);
  },
  finalCB (errors, response){
    console.log("All done!");
  }
})
.promise
.then(([errors, responses])=> console.log(errors, responses));         

Tests

npm test

Release History

• 1.1.1 Package update
• 1.1.0
  • Updates to allow passage of data
  • Added more tests
  • Added autStart option
  • Added ability to chain off of promise
• 1.0.0 Initial release