markdownlint-rule-relative-links/README.md

<h1 align="center">markdownlint-rule-relative-links</h1>

<p align="center">
  <strong>Custom rule for <a href="https://github.com/DavidAnson/markdownlint">markdownlint</a> to validate relative links.</strong>
</p>

<p align="center">
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  <br />
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</p>

## 📜 About

**markdownlint-rule-relative-links** is a [markdownlint](https://github.com/DavidAnson/markdownlint) custom rule to validate relative links.

It ensures that relative links (using `file:` protocol) are working and not "dead" which means that it exists in the file system of the project that uses `markdownlint`.

### Example

File structure:

```txt
├── abc.txt
└── awesome.md
```

With `awesome.md` content:

```md
[abc](./abc.txt)

[Dead link](./dead.txt)
```

Running `markdownlint-cli2` with `markdownlint-rule-relative-links` will output:

```sh
awesome.md:3 relative-links Relative links should be valid [Link "./dead.txt" is dead]
```

### Related links

- [DavidAnson/markdownlint#253](https://github.com/DavidAnson/markdownlint/issues/253)
- [DavidAnson/markdownlint#121](https://github.com/DavidAnson/markdownlint/issues/121)
- [nschonni/markdownlint-valid-links](https://github.com/nschonni/markdownlint-valid-links)

## Prerequisites

- [Node.js](https://nodejs.org/) >= 16.0.0

## Installation

```sh
npm install --save-dev markdownlint-rule-relative-links
```

## Configuration

There are various ways `markdownlint` can be configured using objects, config files etc. For more information on `markdownlint` configuration refer [options.config](https://github.com/DavidAnson/markdownlint#optionsconfig).

We recommend configuring `markdownlint-cli2` over `markdownlint-cli` for compatibility with the `vscode-markdownlint` plugin.

`.markdownlint-cli2.jsonc`

```json
{
  "config": {
    "default": true,
    "relative-links": true
  },
  "globs": ["**/*.{md,mdx}"],
  "ignores": ["**/node_modules"],
  "customRules": ["markdownlint-rule-relative-links"]
}
```

`package.json`

```json
{
  "scripts": {
    "lint:markdown": "markdownlint-cli2"
  }
}
```

## Usage

```sh
npm run lint:markdown
```

## 💡 Contributing

Anyone can help to improve the project, submit a Feature Request, a bug report or even correct a simple spelling mistake.

The steps to contribute can be found in the [CONTRIBUTING.md](./CONTRIBUTING.md) file.

## 📄 License

[MIT](./LICENSE)