promlop

An easy to use zero-dependency vanilla promise loop utility.

WARNING: promlop is still early in development. Stability is not guaranteed and functions may be altered frequently.

Installation

$ npm install promlop

Importing

Commonjs

const promlop = require("promlop");

ES6

import {promWhile, promEach} from "promlop";

Default Namespace

import Promlop from "promlop";

Usage

v0.2.0

promFor

The promise equivalent of a for loop.

import {promFor} from "promlop";

promFor({
  iterator: 0, // Initial value of the [iterator]
  condition: async (iterator: number) => iterator < 10, // Condition to check before running the [promise]
  update: async (iterator: number) => iterator + 1, // Update the [iterator] after running the [promise]
  promise: async (iterator: number) => {
    console.log(iterator);
  } // The promise to run if condidion is truthy
}).then(() => {
  console.log("Ended promise based for loop");
});

promWhile

The promise equivalent of a while loop.

import {promWhile} from "promlop";

let iterator: number = 0;

promWhile({
  condition: async () => iterator < 10, // Condition to check before running the [promise]
  promise: async () => {
    console.log(iterator);
  } // The promise to run if condidion is truthy
}).then(() => {
  console.log("Ended promise based while loop");
});

promDo

The promise equivalent of a do while loop.

import {promDo} from "promlop";

let iterator: number = 0;

promDo({
  condition: async () => iterator < 10, // Condition to check before running the [promise]
  promise: async () => {
    console.log(iterator);
  } // The promise to run if condidion is truthy
}).then(() => {
  console.log("Ended promise based do while loop");
});

promEach

The promise equivalent of a for each loop.

import {promEach} from "promlop";

let people: Array<any> = 0;

let getPeople: Array<() => Promise<any>> = [
  async () => {
    things.push("Mega Man");
  },
  async () => {
    things.push("Blue Beetle");
  },
  async () => {
    things.push("Sonic");
  }
];

promEach({
  promises: getPeople, // An array of promises to loop through
  each: async (result: any) => {} // A function called after each promise
}).then(() => {
  console.log("Ended promise based for each loop");
});

OLD v0.1.2

Version 0.1.2 of promlop supports 3 ways to loop through a series of promises.

Note please only use these functions if you are using v0.1.2 or earlier as newer functions (starting from v0.2.0) may be easier to understand and are still being maintained.

promLoop

const promlop = require("promlop");

let iteration = 0;

promlop
  .promLoop({
    promise: async () => {
      iteration++;

      return {
        continue: iteration < 5 // Loop will continue until this value is false
      };
    }
  })
  .then(() => {})
  .catch((err) => {});

promIterate

import {promIterate} from "promlop";

const promiseOne = async () => {
  console.log("First Promise Complete");
  return {};
};

const promiseTwo = async () => {
  console.log("Second Promise Complete");
  return {};
};

promIterate({
  promises: [promiseOne, promiseTwo], // List of promises to sequentially iterate through
  index: 1 // Start on "promiseTwo".
})
  .then(() => {})
  .catch((err) => {});