markdownlint-rule-relative-links

Custom rule for markdownlint to validate relative links.

📜 About

markdownlint-rule-relative-links is a markdownlint custom rule to validate relative links.

It ensures that relative links (using file: protocol) are working and exists in the file system of the project that uses markdownlint.

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File structure:

``txt
├── abc.txt
└── awesome.md
`

With awesome.md content:

`md
abc

Invalid link
`

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

`sh
awesome.md:3 relative-links Relative links should be valid ["./invalid.txt" should exist in the file system]
`

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- Support images (e.g: !Image).
- Support links fragments similar to the built-in markdownlint rule - MD051 (e.g: Link).
- Ignore external links and absolute paths as it only checks relative links (e.g: https://example.com/ or /absolute/path.png).
- If necessary, absolute paths can be validated too, with root_path configuration option.

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- Only images and links defined using markdown syntax are validated, html syntax is ignored (e.g: or ).

Contributions are welcome to improve the rule, and to alleviate these limitations. See CONTRIBUTING.md for more information.

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- DavidAnson/markdownlint#253
- DavidAnson/markdownlint#121
- nschonni/markdownlint-valid-links

Prerequisites

Node.js >= 22.0.0

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 configuration refer to options.config.

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

.markdownlint-cli2.mjs

`js
import relativeLinksRule from "markdownlint-rule-relative-links"

const config = {
config: {
default: true,
"relative-links": true,
},
globs: ["*/.md"],
ignores: ["**/node_modules"],
customRules: [relativeLinksRule],
}

export default config
`

package.json

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

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GitHub (and, likely, other similar platforms) resolves absolute paths in Markdown links relative to the repository root.

To validate such links, add root_path option to the configuration:

`js
config: {
default: true,
"relative-links": {
root_path: ".",
},
},
`

After this change, all absolute paths will be converted to relative paths, and will be resolved relative to the specified directory.

For example, if you run markdownlint from a subdirectory (if package.json is located in a subdirectory), you should set root_path to "..".

Usage

`sh
node --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 file.

📄 License

MIT