https://github.com/rwu823/is-type-guard

💂is-type-guard - Types checking made easy
https://github.com/rwu823/is-type-guard

guard is ts type typescript

Last synced: about 1 month ago
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💂is-type-guard - Types checking made easy

• Host: GitHub
• URL: https://github.com/rwu823/is-type-guard
• Owner: rwu823
• Created: 2018-10-13T15:25:26.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2023-12-15T05:38:18.000Z (about 1 year ago)
• Last Synced: 2024-04-09T22:53:41.890Z (9 months ago)
• Topics: guard, is, ts, type, typescript
• Language: TypeScript
• Homepage:
• Size: 68.4 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        


  is-type-guard





  

    

  

  

    

  

  

    

  

  



## Why

In TypeScript you can only use `typeof` or `instanceof` as types checking. It gets a little bit trouble if you want to check a plain object.

e.g.

```ts

([]) instanceof Object // true

({}) instanceof Object // true

typeof [] === 'object' //true

typeof {} === 'object' //true

```

## Installation

```sh

$ yarn add is-type-guard

```

## Usage

```ts

import is from 'is-type-guard'

const foo = 'bar'

if(is.string(foo)) {

}

```

## API

### is.string

### is.function

### is.object

### is.array

### is.number

### is.null

### is.undefined

### is.document

### is.process

## ofType

It's based on `Object.prototype.toString`

## Custom types

Easy to extend as your custom types guard.

```ts

import isType, { ofType } from './is-type-guard'

const is = {

  ...isType,

  date: (o: any): o is Date => ofType(o, 'Date'),

  body: (o: any): o is HTMLBodyElement => ofType(o, 'HTMLBodyElement'),

}

```