object-to-arguments

Transforms object's properties into an array of arguments tailored for a specific function, respecting the expected order and handling destructuring and rest parameters when needed.

Installation

npm install object-to-arguments

CLI

npm install object-to-arguments -g

Usage

objectToArguments.call(fn, object);

objectToArguments.call(fn, object);

• fn must be a function reference or a function stringified (e.g. fn.toString()) for which the arguments array will be created for.

• object is a flat object literal containing all the parameters names and its desired arguments. Note that in case of destructuring parameters, the object must still be flat, and the engine will create the structure needed for it.

  • Every argument defined that is not expected as a parameter will be appended to the end of the arguments array (it will be available to be accessed via arguments or via rest parameter ...args)

Example

const objectToArguments = require('object-to-arguments');
 
const fn = (a = 'defaultA', b, ...args) => {
    return { a, b, args};
};
 
const objectArgs = {
    extra1: 'EXTRA1',
    b: 'argB',
    extra2: 'EXTRA2'
};
 
// fnArguments = [ undefined, 'argB', 'EXTRA1', 'EXTRA2' ]
const fnArguments = objectToArguments(fn, objectArgs);
 
// fnReturn = { a: 'defaultA', b: 'argB', args: [ 'EXTRA1', 'EXTRA2' ] }
const fnReturn = fn(...fnArguments);

An example with complex destructuring parameters and default values set in many ways

const objectToArguments = require('object-to-arguments');
 
const fn = function([a, [b, [c, [d,e] = ['dD', 'dE'] ]]] = ['dA', ['dB', ['dC', ]]], {f} = {}, {g = 'dG'} = {}, {h: {i} = {}} = {},{j: {k = 'dK'} = {}} = {},{l: {m, n: {o} = {}} = {}} = {}, {p,q = 'dQ', r} = {}, [[[s,{t: {u} = {}} = {}]]] = [[[]]], {v: [{w} = {}, x = 'dX'] = []} = {}) {
    return { a, b, c, d, e, f, g, i, k, m, o, p, q, r, s, u, w, x, arguments };
};
 
const objectArgs = {
    a: 'aA',
    b: 'aB',
    c: 'aC',
    f: 'aF',
    k: 'aK',
    p: 'aP',
    q: 'aQ',
    s: 'aS',
    u: 'aU',
    v: 'aV',
    w: 'aW',
    x: 'aX',
    extra1: 'EXTRA1',
    extra2: 'EXTRA2'
};
 
const fnArgs = objectToArguments(fn, objectArgs);
const fnReturn = fn(...fnArgs);
 
/////////////////////
// fnArgs will be: //
/////////////////////
// [
//     [
//         "aA",
//         [
//             "aB",
//             [
//                 "aC",
//                 undefined
//             ]
//         ]
//     ],
//     {
//         "f": "aF"
//     },
//     undefined,
//     undefined,
//     {
//         "j": {
//             "k": "aK"
//         }
//     },
//     undefined,
//     {
//         "p": "aP",
//         "q": "aQ"
//     },
//     [
//         [
//             [
//                 "aS",
//                 {
//                     "t": {
//                         "u": "aU"
//                     }
//                 }
//             ]
//         ]
//     ],
//     {
//         "v": [
//             {
//                 "w": "aW"
//             },
//             "aX"
//         ]
//     },
//     "aV",
//     "EXTRA1",
//     "EXTRA2"
// ]
 
 
///////////////////////
// fnReturn will be: //
///////////////////////
// {
//     "a": "aA",
//     "b": "aB",
//     "c": "aC",
//     "d": "dD",
//     "e": "dE",
//     "f": "aF",
//     "g": "dG",
//     "k": "aK",
//     "p": "aP",
//     "q": "aQ",
//     "s": "aS",
//     "u": "aU",
//     "w": "aW",
//     "x": "aX",
//     "arguments": {
//         "0": [
//             "aA",
//             [
//                 "aB",
//                 [
//                     "aC",
//                     null
//                 ]
//             ]
//         ],
//         "1": {
//             "f": "aF"
//         },
//         "4": {
//             "j": {
//                 "k": "aK"
//             }
//         },
//         "6": {
//             "p": "aP",
//             "q": "aQ"
//         },
//         "7": [
//             [
//                 [
//                     "aS",
//                     {
//                         "t": {
//                             "u": "aU"
//                         }
//                     }
//                 ]
//             ]
//         ],
//         "8": {
//             "v": [
//                 {
//                     "w": "aW"
//                 },
//                 "aX"
//             ]
//         },
//         "9": "aV",
//         "10": "EXTRA1",
//         "11": "EXTRA2"
//     }
// }