Call function once

Create a once-only function and it will be never repeated

Installation

npm install once-only

or

yarn add once-only

Usage

import { onceOnly } from 'once-only'

Create:

const createUserOnce = onceOnly(createUser);

Original function will be called only once. It returns cache on a repeated call:

const currentUser = createUserOnce({ userId: 234 });

You can pass configuration object to onceOnly as a second argument:

API

Configuration options:

You can pass config as a second argument.

Default values are: { attach: false, strict: false }

attach option

Attach once function to the original function:

onceOnly(fetchCompany, { attach: true });

Then call it:

const promise = fetchCompany.once({ companyId: 11 });

strict option

You can throw an error when a function is called more than once:

const getIdOnceOnly = onceOnly(getId, { strict: true });
const users = getIdOnceOnly({ userId: 234 }); // Throws an error

Static properties of a once-only function:

Returned function has two static properties (as well as an attached once function):

.called

console.log(fetchUsersOnce.called); // true or false

.cache

console.log(fetchUserOnce.cache); // function: () => cache
const result = fetchUserOnce.cache(); // call cache getter
console.log(result); // logs the result of the first function call

Tip

If you found this packeage useful, please star it on GitHub ★

Definition of "once-only" in English

once-only adjective

That occurs, operates, etc., on one occasion only.

Origin:

1960s; earliest use found in The Sunday Express.

once-only in British adjective

(ˌwʌnsˈəʊnlɪ)

never to be repeated

Examples:

• This is a once-only offer.
• This once-only opportunity to select one of these books absolutely free
• Membership is valid for ten years for a once-only donation of £2,500.

^Collins English Dictionary. Copyright © HarperCollins Publishers

Author

@doasync

Licence

MIT