# util-arity

> Set the length of a function.

Latest version **1.1.0** (published 2017-01-28) · MIT license · 0 weekly downloads

## Install

```sh
npm install util-arity
pnpm add util-arity
yarn add util-arity
bun add util-arity
```

## Health

**Score 25/100 (F)** — status: abandoned.

Positive: has types; no vulnerabilities; high quality score.

Warnings: low downloads; no esm support.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 1.1.0 |
| Published | 2017-01-28 |
| First published | 2014-08-17 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | CommonJS |
| Dependencies | 0 |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 17 |
| Author | Blake Embrey |
| Maintainers | blakeembrey |
| Keywords | arity, function, length, arguments, count |

## Links

- npm: https://www.npmjs.com/package/util-arity
- Repository: https://github.com/blakeembrey/arity
- Issues: https://github.com/blakeembrey/arity/issues
- npm.io page: https://npm.io/package/util-arity

## Recent versions

- 1.1.0 (latest) — 2017-01-28
- 1.0.2 — 2015-12-30
- 1.0.1 — 2015-12-30
- 1.0.0 — 2014-08-17
- 0.0.3 — 2014-08-17

## README

# Arity

[![NPM version][npm-image]][npm-url]
[![NPM downloads][downloads-image]][downloads-url]
[![Build status][travis-image]][travis-url]
[![Test coverage][coveralls-image]][coveralls-url]

> Set a functions arity (the argument count) by proxying function calls.

**P.S.** If you need need to enforce arity and don't care about argument length or `this`, use [`nary`](https://github.com/blakeembrey/nary). It's magnitudes faster than using `.apply` to proxy arguments.

## When would I use this?

It's unlikely you'll need to use this utility in everyday development. The reason I wrote it was for functional utilities and backward compatibility with user expectations. For example, many modules use function arity to decide how the function behaves (e.g. error middleware in `express`, callbacks in `mocha`).

## Installation

```
npm install util-arity --save
```

## Usage

```javascript
var fn = function () {};
var arity = require('util-arity');

var oneArg = arity(1, fn);
var twoArgs = arity(2, fn);
var threeArgs = arity(3, fn);

oneArgs.length; //=> 1
twoArgs.length; //=> 2
threeArgs.length; //=> 3
```

## TypeScript

The typings for this project are available for node module resolution with TypeScript.

## License

MIT

[npm-image]: https://img.shields.io/npm/v/util-arity.svg?style=flat
[npm-url]: https://npmjs.org/package/util-arity
[downloads-image]: https://img.shields.io/npm/dm/util-arity.svg?style=flat
[downloads-url]: https://npmjs.org/package/util-arity
[travis-image]: https://img.shields.io/travis/blakeembrey/arity.svg?style=flat
[travis-url]: https://travis-ci.org/blakeembrey/arity
[coveralls-image]: https://img.shields.io/coveralls/blakeembrey/arity.svg?style=flat
[coveralls-url]: https://coveralls.io/r/blakeembrey/arity?branch=master

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_Source: https://npm.io/package/util-arity · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._