markdownlint-rule-numbered-headings-unique

A custom [markdownlint][markdownlint] rule that checks that headings ending in
a number are unique within the document.

Overview

This rule is for the [Node.js markdownlint library][markdownlint] and its
associated tools. It enforces that any heading ending in a number (e.g., ## 1,
## Test 42) must be unique across the entire Markdown document.

$3

The built-in markdownlint rule [MD024] can require all headings to be globally
unique (which is often too strict) or only check siblings (which can be too
permissive). This rule provides a middle ground: only headings ending in a
number must be unique, which is useful for structured documents like release
notes or test case lists.

Examples of where this is useful:

- Release notes
- Test case documents

Example structure:

``markdown


Obsolete versions

$3

#### New features

#### Bugs fixed

$3

#### New features

#### Bugs fixed

Current versions

$3

#### New features

#### Bugs fixed

$3

#### New features

#### Bugs fixed
`

Installation

`sh
npm install --save-dev markdownlint-rule-numbered-headings-unique
`

Usage

$3

If installed locally, markdownlint will auto-discover the rule by package name.
You can use:

`sh
markdownlint --rules markdownlint-rule-numbered-headings-unique *.md
`

If you want to use a direct path, you can still use:

`sh
markdownlint --rules ./index.cjs *.md
`

$3

If installed locally, markdownlint-cli2 will auto-discover the rule by package
name. You can add it to your config file using the package name:

`jsonc
{
"customRules": [
"markdownlint-rule-numbered-headings-unique"
]
}
`

Or to .markdownlint-cli2.yaml:

`yaml
customRules:
- markdownlint-rule-numbered-headings-unique
`

To use a direct path, you can still reference index.cjs if needed:

`jsonc
{
"customRules": [
"./index.cjs"
]
}
`

$3

If using the [markdownlint extension for VS Code][vscode-markdownlint],
install this package in your workspace and the rule will be auto-discovered.
For advanced usage, see the markdownlint-cli2 examples above or refer to the
extension documentation.

Testing

To run the tests:

`sh
npm test
``

Contributing

Pull requests and issues are welcome! Please ensure your code passes linting
and tests before submitting.

License

MIT

[markdownlint]:
[vscode-markdownlint]:
[MD024]: