# @xmldom/is-dom-node

> TypeScript helper functions to narrow the type of object to a Node descendant

Latest version **1.0.1** (published 2023-10-09) · MIT license · 0 weekly downloads

## Install

```sh
npm install @xmldom/is-dom-node
pnpm add @xmldom/is-dom-node
yarn add @xmldom/is-dom-node
bun add @xmldom/is-dom-node
```

## Health

**Score 40/100 (D)** — status: abandoned.

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

Warnings: low downloads; no esm support.

Negative: abandoned.

## Facts

| | |
|---|---|
| Version | 1.0.1 |
| Published | 2023-10-09 |
| First published | 2023-10-09 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | bundled |
| Module format | CommonJS |
| Node | >= 16 |
| Dependencies | 0 |
| Unpacked size | 21.5 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 5 |
| Author | Chris Barth |
| Maintainers | cjbarth |
| Keywords | dom, node, typescript, narrow, guard |

## Links

- npm: https://www.npmjs.com/package/@xmldom/is-dom-node
- Repository: https://github.com/xmldom/is-dom-node
- Homepage: https://github.com/xmldom/is-dom-node#readme
- Issues: https://github.com/xmldom/is-dom-node/issues
- npm.io page: https://npm.io/package/@xmldom/is-dom-node

## Alternatives

- [babylon](https://npm.io/package/babylon.md) — 5.1M weekly downloads
- [csscolorparser](https://npm.io/package/csscolorparser.md) — 3.7M weekly downloads
- [expr-eval-fork](https://npm.io/package/expr-eval-fork.md) — 1.5M weekly downloads
- [@leeoniya/ufuzzy](https://npm.io/package/@leeoniya/ufuzzy.md) — 247.7K weekly downloads
- [xml-parser](https://npm.io/package/xml-parser.md) — 78.4K weekly downloads

## Recent versions

- 1.0.1 (latest) — 2023-10-09
- 1.0.0 — 2023-10-09

## README

# is-dom-node

![Build Status](https://img.shields.io/github/actions/workflow/status/xmldom/is-dom-node/ci.yml)
![Code Coverage](https://img.shields.io/codecov/c/github/xmldom/is-dom-node)
![NPM Version](https://img.shields.io/npm/v/@xmldom/is-dom-node)
![License](https://img.shields.io/npm/l/@xmldom/is-dom-node)

## Description

`@xmldom/is-dom-node` is a versatile TypeScript library designed to provide robust utility functions for working with DOM nodes. Whether you're developing for the browser or dealing with XML in NodeJS, this library offers a comprehensive set of functions for checking and asserting various types of DOM nodes. It's particularly useful when working with NodeJS libraries like [xpath](https://www.npmjs.com/package/xpath) and [@xmldom/xmldom](https://www.npmjs.com/package/@xmldom/xmldom), as it can validate the objects returned by these libraries.

## Installation

```shell
npm install @xmldom/is-dom-node
```

## Usage

Import the library and use it as follows:

```javascript
import * as isDomNode from "@xmldom/is-dom-node";

const element = document.createElement("div");
const result = isDomNode.isElementNode(element); // Output: true
```

### TypeScript Example

```typescript
import * as isDomNode from "@xmldom/is-dom-node";

function handleNode(node: Node) {
  if (isDomNode.isElementNode(node)) {
    // TypeScript now knows `node` is an Element
    console.log(node.tagName);
  } else if (isDomNode.isTextNode(node)) {
    // TypeScript now knows `node` is a Text node
    console.log(node.wholeText);
  } else {
    try {
      // Assert that the node is a Comment node
      isDomNode.assertIsCommentNode(node);
      // TypeScript now knows `node` is a Comment node
      console.log(node.nodeValue);
    } catch (error) {
      console.error("Node is not a Comment node:", error);
    }
  }
}
```

## API Overview

The API consists of two main types of functions:

### `is...` Functions

These functions return a boolean value indicating whether the given object meets certain criteria:

- `isNodeLike`: Checks if a given value resembles a DOM node.
- `isArrayOfNodes`: Checks if the given value is an array of DOM nodes.
- `isElementNode`, `isAttributeNode`, `isTextNode`, etc.: Check for specific types of DOM nodes.

### `assertIs...` Functions

These functions assert that a given object meets certain criteria and throw an error if it doesn't:

- `assertIsNodeLike`: Asserts that a given value is a DOM node.
- `assertIsArrayOfNodes`: Asserts that the given value is an array of DOM nodes.
- `assertIsElementNode`, `assertIsAttributeNode`, `assertIsTextNode`, etc.: Assert for specific types of DOM nodes.

### TypeScript Type Narrowing

Both the `is...` and `assertIs...` functions can be used for TypeScript type narrowing. After a successful check or assertion, TypeScript will recognize the specific type of the DOM node, allowing for more robust and error-free code.

## Features

- Lightweight
- Written in TypeScript
- Comprehensive tests
- Compatible with NodeJS XML libraries like `xpath` and `@xmldom/xmldom`

## Contributing

Please read [CONTRIBUTING.md](CONTRIBUTING.md) for details on our code of conduct, and the process for submitting pull requests.

## License

This project is licensed under the MIT License - see the [LICENSE.md](LICENSE.md) file for details.

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