eslint-plugin-mark

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no-unused-definition

✅ Recommended ⭐ CommonMark 🌟 GFM

🔗 Rule Source 🔗 Test Source

Disallow unused definitions.

Rule Details ​

This rule disallows unused reference definitions in Markdown documents. Reference definitions provide a way to create reusable links or images, but when they're defined but never referenced, they add unnecessary clutter to your document.

The rule identifies definition entries (e.g., [reference-id]: http://example.com) that are not referenced by any link or image in the document and reports them as violations. Removing unused definitions helps keep your Markdown documents clean and maintainable.

Examples ​

❌ Incorrect ​

Examples of incorrect code for this rule:

md
This paragraph has no references to any definitions.

[unused-link]: https://example.com
[another-unused]: https://example.com/another "With title"
md
This paragraph references [some-link][used-link] but not all definitions.

[used-link]: https://example.com
[unused-link]: https://example.com/unused

✅ Correct ​

Examples of correct code for this rule:

md
This paragraph references [a link][used-link].

[used-link]: https://example.com
md
This paragraph has an image ![Alt text][image-ref].

[image-ref]: https://example.com/image.png "Image title"

When Not To Use It ​

You might want to disable this rule if:

  • You're maintaining a document with intentionally defined but temporarily unused references
  • You're using reference definitions as a form of documentation or note-taking
  • You have a workflow that automatically generates reference definitions, some of which might not be used in every document

AST ​

This rule uses the ReferenceDefinitionHandler utility to track references and their definitions. It examines:

At the end of processing, it identifies any definition nodes that are never referenced by either image or link references.