## What is this?

This is intended to be a fun way of accepting alternatives to `false` or "no" in CLI prompts, web forms, etc. For example, you might want to allow users to define `nil` or `nope` to disable something. 

## Usage

```js
const falsey = require('{%= name %}');

console.log(falsey());       //=> true
console.log(falsey(false));  //=> true
console.log(falsey('nil'));  //=> true
console.log(falsey('nope')); //=> true
console.log(falsey('yes'));  //=> false
```

## Examples

Any value that is not falsey (according to JavaScript) _and is not in the list_ of [falsey keywords](#falsey-keywords) will return `false`:

```js
falsey('abc');
falsey(true);
falsey(1);
falsey('1');
falsey({});
falsey([]);
```

Any value that is falsey (according to JavaScript) _or is in the list_ of [falsey keywords](#falsey-keywords) will return `true`:

```js
falsey();          //=> true
falsey('');        //=> true
falsey(0);         //=> true
falsey(false);     //=> true
falsey(NaN);       //=> true
falsey(null);      //=> true
falsey(undefined); //=> true
falsey(void 0);    //=> true
```

### Falsey keywords

If a value matches one of the built-in "falsey" keywords (all strings) it will return `true`:

- `0`
- `false`
- `nada`
- `nil`
- `nay`
- `nah`
- `negative`
- `no`
- `none`
- `nope`
- `nul`
- `null`
- `nix`
- `nyet`
- `uh-uh`
- `veto`
- `zero`


**Customize falsey keywords**

Pass an array of custom keywords that should return `true` when evaluated as _falsey_:

```js
falsey('zilch', ['no', 'nope', 'nada', 'zilch']); //=> true
```

Disable built-in keywords by passing an empty array:

```js
falsey('nil', []); //=> false
```

**Extend built-in keywords**

Built-in keywords are exposed on the `.keywords` property so that you may extend them with your own keywords:

```js
falsey('zilch', falsey.keywords.concat(['zilch'])); //=> true
```

## Release history

### v1.0

**Breaking changes**

- objects will now always returns `false` 
- more words were added to the built-in list of [falsey keywords](#falsey-keywords)