Project: micromark/micromark

Package: micromark-util-normalize-identifier@1.0.0

  1. Dependents: 0
  2. micromark utility normalize identifiers (as found in references, definitions)
  1. util 145
  2. utility 141
  3. micromark 37
  4. id 4
  5. normalize 3
  6. identifier 2


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micromark utility normalize identifiers.


What is this?

This package exposes an algorithm to normalize identifiers found in markdown.

When should I use this?

This package might be useful when you are making your own micromark extensions.


This package is ESM only. In Node.js (version 16+), install with npm:

npm install micromark-util-normalize-identifier

In Deno with esm.sh:

import {normalizeIdentifier} from 'https://esm.sh/micromark-util-normalize-identifier@1'

In browsers with esm.sh:

<script type="module">
  import {normalizeIdentifier} from 'https://esm.sh/micromark-util-normalize-identifier@1?bundle'


import {normalizeIdentifier} from 'micromark-util-normalize-identifier'

normalizeIdentifier(' a ') // 'A'
normalizeIdentifier('a\t\r\nb') // 'A B'
normalizeIdentifier('ТОЛПОЙ') // 'ТОЛПОЙ'
normalizeIdentifier('Толпой') // 'ТОЛПОЙ'


This module exports the identifier normalizeIdentifier. There is no default export.


Normalize an identifier (as found in references, definitions).

Collapses markdown whitespace, trim, and then lower- and uppercase.

Some characters are considered “uppercase”, such as U+03F4 (ϴ), but if their lowercase counterpart (U+03B8 (θ)) is uppercased will result in a different uppercase character (U+0398 (Θ)). So, to get a canonical form, we perform both lower- and uppercase.

Using uppercase last makes sure keys will never interact with default prototypal values (such as constructor): nothing in the prototype of Object is uppercase.


Normalized identifier (string).


This package is fully typed with TypeScript. It exports no additional types.


Projects maintained by the unified collective are compatible with maintained versions of Node.js.

When we cut a new major release, we drop support for unmaintained versions of Node. This means we try to keep the current release line, micromark-util-normalize-identifier@^2, compatible with Node.js 16. This package works with micromark@^3.


This package is safe. See security.md in micromark/.github for how to submit a security report.


See contributing.md in micromark/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organisation, or community you agree to abide by its terms.


MIT © Titus Wormer