is-number/README.md

# @validatem/is-number

*This validator is designed to be used with [Validatem](https://validatem.cryto.net/), the universal and composable validation library.*

Validates that a given input is a number.

Note that this only accepts actual numbers, not numeric strings; if you are trying to validate a numeric string, you should use [@validatem/is-numeric](https://www.npmjs.com/package/@validatem/is-numeric) instead.

## License, donations, and other boilerplate

Licensed under either the [WTFPL](http://www.wtfpl.net/txt/copying/) or [CC0](https://creativecommons.org/publicdomain/zero/1.0/), at your choice. In practice, that means it's more or less public domain, and you can do whatever you want with it. Giving credit is *not* required, but still very much appreciated! I'd love to [hear from you](mailto:admin@cryto.net) if this module was useful to you.

Creating and maintaining open-source modules is a lot of work. A donation is also not required, but much appreciated! You can donate [here](http://cryto.net/~joepie91/donate.html).

## Example

A runnable version of this example is included in the repository, as `example.js`.

```js
"use strict";

const { validateValue } = require("@validatem/core");
const isNumber = require("@validatem/is-number");

console.log(validateValue(42, [ isNumber ])); // 42

console.log(validateValue("hello world", [ isNumber ])); /*
	AggregrateValidationError: One or more validation errors occurred:
	 - At (root): Must be a number
*/

```

## API

__If you are new to Validatem,__ please read the documentation on the [Validatem website](https://validatem.cryto.net/) first - it will explain how the general API works, and how you should use validator modules with it.

### isNumber

Not callable. Validates that the input is a number. When validation passes, it returns the original number as-is.

Possible error codes:
- __validatem.is-number.number:__ The input was not a number.
- __validatem.is-number.nan:__ The input was NaN.

## Changelog

### 1.0.0 (July 14, 2024)

Initial release.