mdast-util-heading-range

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[mdast][] utility to find headings and replace the content in their section.

* What is this?
* When should I use this?
* Install
* Use
* API
* headingRange(tree, test|options, handler)
* Handler
* Info
* Options
* Test
* TestFunction
* Types
* Compatibility
* Security
* Related
* Contribute
* License

What is this?

This package is a utility that lets you find a certain heading, then takes the
content in their section (from it to the next heading of the same or lower
depth), and calls a given handler with the result, so that you can change or
replace things.

When should I use this?

This utility is typically useful when you have certain sections that can be
generated.
For example, this utility is used by [remark-toc][remark-toc] to update the
above Contents heading.

A similar package, [mdast-zone][mdast-zone], does the same but uses comments
to mark the start and end of sections.

Install

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

``sh npm install mdast-util-heading-range`

In Deno with [esm.sh][esmsh]:

`js import {headingRange} from 'https://esm.sh/mdast-util-heading-range@4'`

In browsers with [esm.sh][esmsh]:

`html`

`Use`

Say we have the following file, example.md:

`markdown

`Foo`

Bar.

`Baz`

…and a module example.js:

`js import {read} from 'to-vfile' import {remark} from 'remark' import {headingRange} from 'mdast-util-heading-range'

const file = await remark() .use(myPluginThatReplacesFoo) .process(await read('example.md'))

console.log(String(file))

/* @type {import('unified').Plugin<[], import('mdast').Root>} / function myPluginThatReplacesFoo() { return function (tree) { headingRange(tree, 'foo', function (start, nodes, end) { return [ start, {type: 'paragraph', children: [{type: 'text', value: 'Qux.'}]}, end ] }) } }`

…now running node example.js yields:

`markdown

`Foo`

Qux.

`Baz`

API

This package exports the identifier [headingRange][api-heading-range]. There is no default export.

`$3`

Search tree for a heading matching testand change its “section” withhandler.

A “section” ranges from the matched heading until the next heading of the same or lower depth, or the end of the document.

If ignoreFinalDefinitions: true, final definitions “in” the section are excluded.

###### Parameters

* tree ([Node][node]) — tree to change *test ([Test][api-test]) — same as passing{test: Test}*options ([Options][api-options]) — configuration *handler ([Handler][api-handler]) — handle a section

###### Returns

Nothing (undefined).

`$3`

Callback called when a section is found (TypeScript type).

###### Parameters

* start ([Heading][heading]) — start of section (a heading node matchingtest) *nodes ([Array][node]) — nodes betweenstart and end*end ([Node][node] or undefined) — end of section, if any *info ([Info][api-info]) — extra info

###### Returns

Results (Array, optional).

If nothing is returned, nothing will be changed. If an array of nodes (can includenull and undefined) is returned, the original section will be replaced by those nodes.

`$3`

Extra info (TypeScript type).

###### Fields

* parent ([Node][node]) — parent of the section *start (number) — index ofstart in parent*end (number or undefined) — index ofend in parent

`$3`

Configuration (TypeScript type).

###### Fields

* test ([Test][api-test]) — test for a heading *ignoreFinalDefinitions (boolean, default: false) — ignore final definitions otherwise in the section

`$3`

Test for a heading (TypeScript type).

When string, wrapped in new RegExp('^(' + value + ')$', 'i'); whenRegExp, wrapped in (value) => expression.test(value)

###### Type

`ts export type Test = RegExp | TestFunction | string`

`$3`

Check if a node matches (TypeScript type).

###### Parameters

* value (string) — plain-text heading *node ([Heading][heading]) — heading node

###### Returns

Whether this is the heading that is searched for (boolean, optional).

`Types`

This package is fully typed with [TypeScript][]. This package exports the types [Handler][api-handler], [Info][api-info], [Options][api-options], [Test][api-test], and [TestFunction][api-test-function].

`Compatibility`

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,mdast-util-heading-range@^4, compatible with Node.js 16.

`Security`

Improper use of handlercan open you up to a [cross-site scripting (XSS)][xss] attack as the value it returns is injected into the syntax tree. This can become a problem if the tree is later transformed to [hast][hast]. The following example shows how a script is injected that could run when loaded in a browser.

`js /* @type {import('mdast-util-heading-range').Handler} / function handler(start, nodes, end) { return [start, {type: 'html', value: ''}, end] }`

Yields:

`markdown

`Foo`

`Baz`

Either do not use user input in handleror use [hast-util-santize][hast-util-sanitize].

`Related`

* mdast-zone— similar but uses comments to mark the start and end of sections

`Contribute`

See [contributing.md][contributing] in [syntax-tree/.github][health] for ways to get started. See [support.md`][support] for ways to get help.

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

License

[MIT][license] © [Titus Wormer][author]

[build-badge]: https://github.com/syntax-tree/mdast-util-heading-range/workflows/main/badge.svg

[build]: https://github.com/syntax-tree/mdast-util-heading-range/actions

[coverage-badge]: https://img.shields.io/codecov/c/github/syntax-tree/mdast-util-heading-range.svg

[coverage]: https://codecov.io/github/syntax-tree/mdast-util-heading-range

[downloads-badge]: https://img.shields.io/npm/dm/mdast-util-heading-range.svg

[downloads]: https://www.npmjs.com/package/mdast-util-heading-range

[size-badge]: https://img.shields.io/badge/dynamic/json?label=minzipped%20size&query=$.size.compressedSize&url=https://deno.bundlejs.com/?q=mdast-util-heading-range

[size]: https://bundlejs.com/?q=mdast-util-heading-range

[sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg

[backers-badge]: https://opencollective.com/unified/backers/badge.svg

[collective]: https://opencollective.com/unified

[chat-badge]: https://img.shields.io/badge/chat-discussions-success.svg

[chat]: https://github.com/syntax-tree/unist/discussions

[npm]: https://docs.npmjs.com/cli/install

[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

[esmsh]: https://esm.sh

[typescript]: https://www.typescriptlang.org

[license]: license

[author]: https://wooorm.com

[health]: https://github.com/syntax-tree/.github

[contributing]: https://github.com/syntax-tree/.github/blob/main/contributing.md

[support]: https://github.com/syntax-tree/.github/blob/main/support.md

[coc]: https://github.com/syntax-tree/.github/blob/main/code-of-conduct.md

[mdast]: https://github.com/syntax-tree/mdast

[node]: https://github.com/syntax-tree/unist#node

[heading]: https://github.com/syntax-tree/mdast#heading

[xss]: https://en.wikipedia.org/wiki/Cross-site_scripting

[hast]: https://github.com/syntax-tree/hast

[mdast-zone]: https://github.com/syntax-tree/mdast-zone

[hast-util-sanitize]: https://github.com/syntax-tree/hast-util-sanitize

[remark-toc]: https://github.com/remarkjs/remark-toc

[api-heading-range]: #headingrangetree-testoptions-handler

[api-handler]: #handler

[api-options]: #options

[api-test]: #test

[api-test-function]: #testfunction

[api-info]: #info

mdast-util-heading-range

[mdast][] utility to find headings and replace the content in their section.

What is this?

When should I use this?

This utility is typically useful when you have certain sections that can be
generated.
For example, this utility is used by [remark-toc][remark-toc] to update the
above Contents heading.

A similar package, [mdast-zone][mdast-zone], does the same but uses comments
to mark the start and end of sections.

Install

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

``sh npm install mdast-util-heading-range`

In Deno with [esm.sh][esmsh]:

`js import {headingRange} from 'https://esm.sh/mdast-util-heading-range@4'`

In browsers with [esm.sh][esmsh]:

`html`

`Use`

Say we have the following file, example.md:

`markdown

`Foo`

Bar.

`Baz`

…and a module example.js:

`js import {read} from 'to-vfile' import {remark} from 'remark' import {headingRange} from 'mdast-util-heading-range'

const file = await remark() .use(myPluginThatReplacesFoo) .process(await read('example.md'))

console.log(String(file))

…now running node example.js yields:

`markdown

`Foo`

Qux.

`Baz`

API

This package exports the identifier [headingRange][api-heading-range]. There is no default export.

`$3`

Search tree for a heading matching testand change its “section” withhandler.

A “section” ranges from the matched heading until the next heading of the same or lower depth, or the end of the document.

If ignoreFinalDefinitions: true, final definitions “in” the section are excluded.

###### Parameters

###### Returns

Nothing (undefined).

`$3`

Callback called when a section is found (TypeScript type).

###### Parameters

###### Returns

Results (Array, optional).

If nothing is returned, nothing will be changed. If an array of nodes (can includenull and undefined) is returned, the original section will be replaced by those nodes.

`$3`

Extra info (TypeScript type).

###### Fields

* parent ([Node][node]) — parent of the section *start (number) — index ofstart in parent*end (number or undefined) — index ofend in parent

`$3`

Configuration (TypeScript type).

###### Fields

* test ([Test][api-test]) — test for a heading *ignoreFinalDefinitions (boolean, default: false) — ignore final definitions otherwise in the section

`$3`

Test for a heading (TypeScript type).

When string, wrapped in new RegExp('^(' + value + ')$', 'i'); whenRegExp, wrapped in (value) => expression.test(value)

###### Type

`ts export type Test = RegExp | TestFunction | string`

`$3`

Check if a node matches (TypeScript type).

###### Parameters

* value (string) — plain-text heading *node ([Heading][heading]) — heading node

###### Returns

Whether this is the heading that is searched for (boolean, optional).

`Types`

`Compatibility`

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,mdast-util-heading-range@^4, compatible with Node.js 16.

`Security`

`js /* @type {import('mdast-util-heading-range').Handler} / function handler(start, nodes, end) { return [start, {type: 'html', value: ''}, end] }`

Yields:

`markdown

`Foo`

`Baz`

Either do not use user input in handleror use [hast-util-santize][hast-util-sanitize].

`Related`

* mdast-zone— similar but uses comments to mark the start and end of sections

`Contribute`

See [contributing.md][contributing] in [syntax-tree/.github][health] for ways to get started. See [support.md`][support] for ways to get help.

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

License

[build-badge]: https://github.com/syntax-tree/mdast-util-heading-range/workflows/main/badge.svg

[build]: https://github.com/syntax-tree/mdast-util-heading-range/actions

[coverage-badge]: https://img.shields.io/codecov/c/github/syntax-tree/mdast-util-heading-range.svg

[coverage]: https://codecov.io/github/syntax-tree/mdast-util-heading-range

[downloads-badge]: https://img.shields.io/npm/dm/mdast-util-heading-range.svg

[downloads]: https://www.npmjs.com/package/mdast-util-heading-range

[size-badge]: https://img.shields.io/badge/dynamic/json?label=minzipped%20size&query=$.size.compressedSize&url=https://deno.bundlejs.com/?q=mdast-util-heading-range

[size]: https://bundlejs.com/?q=mdast-util-heading-range

[sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg

[backers-badge]: https://opencollective.com/unified/backers/badge.svg

[collective]: https://opencollective.com/unified

[chat-badge]: https://img.shields.io/badge/chat-discussions-success.svg

[chat]: https://github.com/syntax-tree/unist/discussions

[npm]: https://docs.npmjs.com/cli/install

[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

[esmsh]: https://esm.sh

[typescript]: https://www.typescriptlang.org

[license]: license

[author]: https://wooorm.com

[health]: https://github.com/syntax-tree/.github

[contributing]: https://github.com/syntax-tree/.github/blob/main/contributing.md

[support]: https://github.com/syntax-tree/.github/blob/main/support.md

[coc]: https://github.com/syntax-tree/.github/blob/main/code-of-conduct.md

[mdast]: https://github.com/syntax-tree/mdast

[node]: https://github.com/syntax-tree/unist#node

[heading]: https://github.com/syntax-tree/mdast#heading

[xss]: https://en.wikipedia.org/wiki/Cross-site_scripting

[hast]: https://github.com/syntax-tree/hast

[mdast-zone]: https://github.com/syntax-tree/mdast-zone

[hast-util-sanitize]: https://github.com/syntax-tree/hast-util-sanitize

[remark-toc]: https://github.com/remarkjs/remark-toc

[api-heading-range]: #headingrangetree-testoptions-handler

[api-handler]: #handler

[api-options]: #options

[api-test]: #test

[api-test-function]: #testfunction

[api-info]: #info