EVL

😈 Function fallback when error.

Likes NVL but for Error fallback.

Installation

Via npm:

npm install evl

Via Yarn:

yarn add evl

Usage

const evl = require('evl');

const err = () => {
	throw new Error('An error. 😱');
};
const one = () => 1;
const two = () => 2;
const add = (a, b) => a + b;
const multiply = (a, b) => a * b;

/*
 * No arguments
 */
const a = evl(one, two)(); // a is 1
const b = evl(err, two)(); // b is 2

/*
 * With arguments
 */
// To call add(1, 2) or multiply(3, 4)
const c = evl(add, multiply)([1, 2], [3, 4]); // c is 3 (1 + 2 from add function)
// To call err(1, 2) or multiply(3, 4)
const d = evl(err, multiply)([1, 2], [3, 4]); // d is 12 (3 * 4 from multiply function)

You can also pass non-function.

const evl = require('evl');

const err = () => {
	throw new Error('An error. 💩');
};

evl(err, 'I am fallback value.') // -> 'I am fallback value.'

API

evl(mainFunction, fallbackFunction)

Create an invoke function that will return the value from either of given functions.

mainFunction

Type: Function

A main function that you expect it to work.

If you pass non-function value to this parameter, evl will return it back from invoke function.

fallbackFunction

Type: Function

A fallback function that will work when main function throw an error.

If you pass non-function value to this parameter, evl will return it back from invoke function when main function not work.

invoke(mainFuncArgs, fallbackFuncArgs) - Invoke Function

Return a value of either of given functions with given arguments.

If both mainFunction and fallbackFunction have error, invoke will return null.

mainFuncArgs

Type: Array
Default: []

Arguments of evl's mainFunction.

fallbackFuncArgs

Type: Array
Default: []

Arguments of evl's fallbackFunction.