chained-functions v0.1.5

Chained Functions

Run functions sequentially. Pass the return from one to another.

Usage

Import chain and call it passing the functions as parameters.

import { chain } from 'chained-functions';

function set3() {
    return 3;
}

function sum10(curr) {
    return curr + 10;
}

function minus5(curr) {
    return curr - 5;
}

const result = chain(set3, sum10, minus5)
console.log(result) // 8

Chaining Async Functions

You can use chainAsync when dealing with async functions.

import { chainAsync } from 'chained-functions';

async function fetchFromDB() {
    ... // fetching data
    return dataResponse;
}

function formatResponse(curr) {
    return { message: curr }
}

(async () => {
    const result = await chainAsync(fetchFromDB, formatResponse)
    console.log(result) // { message: dataResponse }
})()

Breaking the Chain and Inserting Values

When you need to break the chain at a certain step or insert a value at the beginning of the chain, use the breakChain and addLink functions.

import { chain, addLink, breakChain } from 'chained-functions';

const result = chain(
  addLink(40),
  (curr) => breakChain("res: " + curr),
  (curr) => curr + 50 // This step will not be executed
)

console.log(result) // res: 40

To break the chain and return only the current value, return the breakChain function itself (without calling it).

import { chain, addLink, breakChain } from 'chained-functions';

const result = chain(
  addLink(40),
  () => breakChain,
  (curr) => curr + 50 // This step will not be executed
)

console.log(result) // 40

Typing the returned value

When using Typescript, you can set the return type as a Generic of the chain/asyncChain function.

import { chain } from 'chained-functions';

const result = chain<number>(firstFn, secondFn, lastFn)

To get the precise type, use ReturnType<> with the last function.

import { chain } from 'chained-functions';

const result = chain<ReturnType<typeof lastFn>>(firstFn, secondFn, lastFn)

Installation

1. Install it using npm or yarn
   • npm i chained-functions
   • yarn add chained-functions
2. Import it
   • import {chain} from 'chained-functions'
3. Use it 😄