astro/packages/webapi/README.md

# WebAPI

**WebAPI** lets you use Web APIs not present in Node v16 and later.

```sh
npm install @astrojs/webapi
```

```js
import { polyfill } from '@astrojs/webapi'

polyfill(globalThis)

const t = new EventTarget()
const e = new CustomEvent('hello')

t.addEventListener('hello', console.log)

t.dispatchEvent(e) // logs `e` event from `t`
```

These APIs are combined from popular open source projects and configured to share implementation details. This allows their behavior to match browser expectations as well as reduce their combined memory footprint.

## Features

- [ByteLengthQueuingStrategy](https://developer.mozilla.org/en-US/docs/Web/API/ByteLengthQueuingStrategy)
- [CanvasRenderingContext2D](https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D)
- [CSSStyleSheet](https://developer.mozilla.org/en-US/docs/Web/API/CSSStyleSheet)
- [CountQueuingStrategy](https://developer.mozilla.org/en-US/docs/Web/API/CountQueuingStrategy)
- [CustomElementRegistry](https://developer.mozilla.org/en-US/docs/Web/API/CustomElementRegistry)
- [CustomEvent](https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent)
- [DOMException](https://developer.mozilla.org/en-US/docs/Web/API/DOMException)
- [Document](https://developer.mozilla.org/en-US/docs/Web/API/Document)
- [DocumentFragment](https://developer.mozilla.org/en-US/docs/Web/API/DocumentFragment)
- [Element](https://developer.mozilla.org/en-US/docs/Web/API/Element)
- [Event](https://developer.mozilla.org/en-US/docs/Web/API/Event)
- [EventTarget](https://developer.mozilla.org/en-US/docs/Web/API/EventTarget)
- [File](https://developer.mozilla.org/en-US/docs/Web/API/File)
- [FormData](https://developer.mozilla.org/en-US/docs/Web/API/FormData)
- [HTMLDocument](https://developer.mozilla.org/en-US/docs/Web/API/HTMLDocument)
- [HTMLElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement)
- [HTMLBodyElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLBodyElement)
- [HTMLCanvasElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement)
- [HTMLDivElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLDivElement)
- [HTMLHeadElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLHeadElement)
- [HTMLHtmlElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLHtmlElement)
- [HTMLImageElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLImageElement)
- [HTMLSpanElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLSpanElement)
- [HTMLStyleElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLStyleElement)
- [HTMLTemplateElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLTemplateElement)
- [HTMLUnknownElement](https://developer.mozilla.org/en-US/docs/Web/API/HTMLUnknownElement)
- [Headers](https://developer.mozilla.org/en-US/docs/Web/API/Headers)
- [IntersectionObserver](https://developer.mozilla.org/en-US/docs/Web/API/IntersectionObserver)
- [Image](https://developer.mozilla.org/en-US/docs/Web/API/Image)
- [ImageData](https://developer.mozilla.org/en-US/docs/Web/API/ImageData)
- [MediaQueryList](https://developer.mozilla.org/en-US/docs/Web/API/MediaQueryList)
- [MutationObserver](https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver)
- [Node](https://developer.mozilla.org/en-US/docs/Web/API/Node)
- [NodeIterator](https://developer.mozilla.org/en-US/docs/Web/API/NodeIterator)
- [OffscreenCanvas](https://developer.mozilla.org/en-US/docs/Web/API/OffscreenCanvas)
- [ReadableByteStreamController](https://developer.mozilla.org/en-US/docs/Web/API/ReadableByteStreamController)
- [ReadableStream](https://developer.mozilla.org/en-US/docs/Web/API/ReadableStream)
- [ReadableStreamBYOBReader](https://developer.mozilla.org/en-US/docs/Web/API/ReadableStreamBYOBReader)
- [ReadableStreamBYOBRequest](https://developer.mozilla.org/en-US/docs/Web/API/ReadableStreamBYOBRequest)
- [ReadableStreamDefaultController](https://developer.mozilla.org/en-US/docs/Web/API/ReadableStreamDefaultController)
- [ReadableStreamDefaultReader](https://developer.mozilla.org/en-US/docs/Web/API/ReadableStreamDefaultReader)
- [Request](https://developer.mozilla.org/en-US/docs/Web/API/Request)
- [Response](https://developer.mozilla.org/en-US/docs/Web/API/Response)
- [ShadowRoot](https://developer.mozilla.org/en-US/docs/Web/API/ShadowRoot)
- [Storage](https://developer.mozilla.org/en-US/docs/Web/API/Storage)
- [StyleSheet](https://developer.mozilla.org/en-US/docs/Web/API/StyleSheet)
- [TransformStream](https://developer.mozilla.org/en-US/docs/Web/API/TransformStream)
- [TreeWalker](https://developer.mozilla.org/en-US/docs/Web/API/TreeWalker)
- [WritableStream](https://developer.mozilla.org/en-US/docs/Web/API/WritableStream)
- [WritableStreamDefaultController](https://developer.mozilla.org/en-US/docs/Web/API/WritableStreamDefaultController)
- [WritableStreamDefaultWriter](https://developer.mozilla.org/en-US/docs/Web/API/WritableStreamDefaultWriter)
- [Window](https://developer.mozilla.org/en-US/docs/Web/API/Window)
- [cancelAnimationFrame](https://developer.mozilla.org/en-US/docs/Web/API/Window/cancelAnimationFrame)
- [cancelIdleCallback](https://developer.mozilla.org/en-US/docs/Web/API/cancelIdleCallback)
- [clearTimeout](https://developer.mozilla.org/en-US/docs/Web/API/clearTimeout)
- [fetch](https://developer.mozilla.org/en-US/docs/Web/API/fetch)
- [localStorage](https://developer.mozilla.org/en-US/docs/Web/API/localStorage)
- [requestAnimationFrame](https://developer.mozilla.org/en-US/docs/Web/API/requestAnimationFrame)
- [requestIdleCallback](https://developer.mozilla.org/en-US/docs/Web/API/requestIdleCallback)
- [setTimeout](https://developer.mozilla.org/en-US/docs/Web/API/setTimeout)
- [structuredClone](https://developer.mozilla.org/en-US/docs/Web/API/structuredClone)
- [URLPattern](https://developer.mozilla.org/en-US/docs/Web/API/URLPattern)

## Usage

You can use WebAPIs as individual exports.

```js
import { Event, EventTarget, File, fetch, Response } from '@astrojs/webapi'
```

You can apply WebAPIs to an object, like `globalThis`.

```js
import { polyfill } from '@astrojs/webapi'

polyfill(globalThis)
```

## Polyfill Options

The `exclude` option receives a list of WebAPIs to exclude from polyfilling.

```js
polyfill(globalThis, {
  // disables polyfills for setTimeout clearTimeout
  exclude: 'setTimeout clearTimeout',
})
```

The `exclude` option accepts shorthands to exclude multiple polyfills. These shorthands end with the plus sign (`+`).

```js
polyfill(globalThis, {
  // disables polyfills for setTimeout clearTimeout
  exclude: 'Timeout+',
})
```

```js
polyfill(globalThis, {
  // disables polyfills for Node, Window, Document, HTMLElement, etc.
  exclude: 'Node+',
})
```

```js
polyfill(globalThis, {
  // disables polyfills for Event, EventTarget, Node, Window, Document, HTMLElement, etc.
  exclude: 'Event+',
})
```

| Shorthand      | Excludes |
|:-------------- |:-------- |
| `Document+`    | `Document`, `HTMLDocument` |
| `Element+`     | `Element`, and exclusions from `HTMLElement+` |
| `Event+`       | `Event`, `CustomEvent`, `EventTarget`, `MediaQueryList`, `Window`, and exclusions from `Node+` |
| `EventTarget+` | `Event`, `CustomEvent`, `EventTarget`, `MediaQueryList`, `Window`, and exclusions from `Node+` |
| `HTMLElement+` | `CustomElementsRegistry`, `HTMLElement`, `HTMLBodyElement`, `HTMLCanvasElement`, `HTMLDivElement`, `HTMLHeadElement`, `HTMLHtmlElement`, `HTMLImageElement`, `HTMLStyleElement`, `HTMLTemplateElement`, `HTMLUnknownElement`, `Image` |
| `Node+`        | `Node`, `DocumentFragment`, `ShadowRoot`, `Document`, `HTMLDocument`, and exclusions from `Element+` |
| `StyleSheet+`  | `StyleSheet`, `CSSStyleSheet` |

---



## License & Attribution

Thank you to Jon Neal for his work on the original [webapi](https://github.com/astro-community/webapi) project that this package is forked from. Licensed under the CC0-1.0 License.

Code from [event-target-shim](https://www.npmjs.com/package/event-target-shim) is licensed under the MIT License (MIT), Copyright Toru Nagashima.