promise-map-series

promise-map-series

Call an iterator function for each element of an array in series, ensuring that no iterator is called before the promise returned by the previous iterator is fulfilled, in effect preventing parallel execution. Like async.mapSeries, but for promises.

Installation

npm install --save promise-map-series

Usage

var mapSeries = require('promise-map-series')

mapSeries(array, iterator[, thisArg]).then(function (newArray) {
  ...
})

• array: An array of values (should not be promises).

• iterator: Function that returns a promise or a value for the new array. The iterator will be called once for each element. If iterator returns a promise, then iterator will only be called for the next element once that promise is fulfilled. If the promise is rejected or iterator throws an error, iteration will stop immediately and mapSeries returns a rejected promise. The iterator function receives three arguments:

  • item: The current item in the array.

  • index: The current index in the array.

  • array: The original array argument.

• thisArg (optional): Value to use as this when executing iterator.

Similar packages

Other packages similar to promise-map-series

p-map-series

p-map-series is a similar package that also maps over an array of items and applies a promise-returning function to each item in series. It is similar to promise-map-series in functionality but is part of the 'p-*' series of promise utilities by Sindre Sorhus, which are known for their simplicity and reliability.

async

The async package provides a wide range of utilities for working with asynchronous JavaScript, including a series method that can be used to run an array of functions in series. While it offers more features than promise-map-series, it is also heavier and more complex.

bluebird

Bluebird is a fully-featured promise library that includes a mapSeries method for sequentially processing an array of items. It offers more advanced features and optimizations compared to promise-map-series, but it is also a larger library.