https://github.com/syntax-tree/mdast-util-mdxjs-esm
mdast extension to parse and serialize MDX.js ESM (import/exports)
https://github.com/syntax-tree/mdast-util-mdxjs-esm
esm mdast mdast-util mdx mdxjs
Last synced: about 2 months ago
JSON representation
mdast extension to parse and serialize MDX.js ESM (import/exports)
- Host: GitHub
- URL: https://github.com/syntax-tree/mdast-util-mdxjs-esm
- Owner: syntax-tree
- License: mit
- Created: 2020-11-30T10:11:57.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2024-09-13T10:00:51.000Z (8 months ago)
- Last Synced: 2025-02-16T21:06:44.005Z (3 months ago)
- Topics: esm, mdast, mdast-util, mdx, mdxjs
- Language: JavaScript
- Homepage: https://unifiedjs.com
- Size: 131 KB
- Stars: 8
- Watchers: 8
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
- License: license
Awesome Lists containing this project
README
# mdast-util-mdxjs-esm
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[mdast][] extensions to parse and serialize [MDX][] ESM (import/exports).
## Contents
* [What is this?](#what-is-this)
* [When to use this](#when-to-use-this)
* [Install](#install)
* [Use](#use)
* [API](#api)
* [`mdxjsEsmFromMarkdown()`](#mdxjsesmfrommarkdown)
* [`mdxjsEsmToMarkdown()`](#mdxjsesmtomarkdown)
* [`MdxjsEsm`](#mdxjsesm)
* [`MdxjsEsmHast`](#mdxjsesmhast)
* [HTML](#html)
* [Syntax](#syntax)
* [Syntax tree](#syntax-tree)
* [Nodes](#nodes)
* [Content model](#content-model)
* [Types](#types)
* [Compatibility](#compatibility)
* [Related](#related)
* [Contribute](#contribute)
* [License](#license)
## What is this?
This package contains two extensions that add support for MDX ESM syntax in
markdown to [mdast][].
These extensions plug into
[`mdast-util-from-markdown`][mdast-util-from-markdown] (to support parsing
ESM in markdown into a syntax tree) and
[`mdast-util-to-markdown`][mdast-util-to-markdown] (to support serializing
ESM in syntax trees to markdown).
## When to use this
You can use these extensions when you are working with
`mdast-util-from-markdown` and `mdast-util-to-markdown` already.
When working with `mdast-util-from-markdown`, you must combine this package
with [`micromark-extension-mdxjs-esm`][extension].
When you are working with syntax trees and want all of MDX, use
[`mdast-util-mdx`][mdast-util-mdx] instead.
All these packages are used in [`remark-mdx`][remark-mdx], which
focusses on making it easier to transform content by abstracting these
internals away.
## Install
This package is [ESM only][esm].
In Node.js (version 16+), install with [npm][]:
```sh
npm install mdast-util-mdxjs-esm
```
In Deno with [`esm.sh`][esmsh]:
```js
import {mdxjsEsmFromMarkdown, mdxjsEsmToMarkdown} from 'https://esm.sh/mdast-util-mdxjs-esm@2'
```
In browsers with [`esm.sh`][esmsh]:
```html
import {mdxjsEsmFromMarkdown, mdxjsEsmToMarkdown} from 'https://esm.sh/mdast-util-mdxjs-esm@2?bundle'
```
## Use
Say our document `example.mdx` contains:
```mdx
import a from 'b'
export const c = ''
d
```
…and our module `example.js` looks as follows:
```js
import fs from 'node:fs/promises'
import * as acorn from 'acorn'
import {fromMarkdown} from 'mdast-util-from-markdown'
import {toMarkdown} from 'mdast-util-to-markdown'
import {mdxjsEsm} from 'micromark-extension-mdxjs-esm'
import {mdxjsEsmFromMarkdown, mdxjsEsmToMarkdown} from 'mdast-util-mdxjs-esm'
const doc = await fs.readFile('example.mdx')
const tree = fromMarkdown(doc, {
extensions: [mdxjsEsm({acorn, addResult: true})],
mdastExtensions: [mdxjsEsmFromMarkdown()]
})
console.log(tree)
const out = toMarkdown(tree, {extensions: [mdxjsEsmToMarkdown()]})
console.log(out)
```
…now running `node example.js` yields (positional info removed for brevity):
```js
{
type: 'root',
children: [
{
type: 'mdxjsEsm',
value: "import a from 'b'\nexport const c = ''",
data: {
estree: {
type: 'Program',
body: [
{
type: 'ImportDeclaration',
specifiers: [
{
type: 'ImportDefaultSpecifier',
local: {type: 'Identifier', name: 'a'}
}
],
source: {type: 'Literal', value: 'b', raw: "'b'"}
},
{
type: 'ExportNamedDeclaration',
declaration: {
type: 'VariableDeclaration',
declarations: [
{
type: 'VariableDeclarator',
id: {type: 'Identifier', name: 'c'},
init: {type: 'Literal', value: '', raw: "''"}
}
],
kind: 'const'
},
specifiers: [],
source: null
}
],
sourceType: 'module'
}
}
},
{type: 'paragraph', children: [{type: 'text', value: 'd'}]}
]
}
```
```markdown
import a from 'b'
export const c = ''
d
```
## API
This package exports the identifiers
[`mdxjsEsmFromMarkdown`][api-mdxjs-esm-from-markdown] and
[`mdxjsEsmToMarkdown`][api-mdxjs-esm-to-markdown].
There is no default export.
### `mdxjsEsmFromMarkdown()`
Create an extension for [`mdast-util-from-markdown`][mdast-util-from-markdown]
to enable MDX.js ESM in markdown.
When using the [micromark syntax extension][extension] with `addResult`, nodes
will have a `data.estree` field set to an ESTree [`Program`][program] node.
###### Returns
Extension for `mdast-util-from-markdown` to enable MDX.js ESM
([`FromMarkdownExtension`][from-markdown-extension]).
### `mdxjsEsmToMarkdown()`
Create an extension for [`mdast-util-to-markdown`][mdast-util-to-markdown]
to enable MDX.js ESM in markdown.
###### Returns
Extension for `mdast-util-to-markdown` to enable MDX.js ESM
([`ToMarkdownExtension`][to-markdown-extension]).
### `MdxjsEsm`
MDX ESM (import/export) node (TypeScript type).
###### Type
```ts
import type {Program} from 'estree-jsx'
import type {Data, Literal} from 'mdast'
interface MdxjsEsm extends Literal {
type: 'mdxjsEsm'
data?: MdxjsEsmData | undefined
}
export interface MdxjsEsmData extends Data {
estree?: Program | null | undefined
}
```
### `MdxjsEsmHast`
Same as [`MdxjsEsm`][api-mdxjs-esm], but registered with `@types/hast`
(TypeScript type).
###### Type
```ts
import type {Program} from 'estree-jsx'
import type {Data, Literal} from 'hast'
interface MdxjsEsmHast extends Literal {
type: 'mdxjsEsm'
data?: MdxjsEsmHastData | undefined
}
export interface MdxjsEsmHastData extends Data {
estree?: Program | null | undefined
}
```
## HTML
MDX ESM has no representation in HTML.
Though, when you are dealing with MDX, you will likely go *through* hast.
You can enable passing MDX ESM through to hast by configuring
[`mdast-util-to-hast`][mdast-util-to-hast] with `passThrough: ['mdxjsEsm']`.
## Syntax
See [Syntax in `micromark-extension-mdxjs-esm`][syntax].
## Syntax tree
The following interfaces are added to **[mdast][]** by this utility.
### Nodes
#### `MdxjsEsm`
```idl
interface MdxjsEsm <: Literal {
type: 'mdxjsEsm'
}
```
**MdxjsEsm** (**[Literal][dfn-literal]**) represents ESM import/exports
embedded in MDX.
It can be used where **[flow][dfn-flow-content]** content is expected.
Its content is represented by its `value` field.
For example, the following Markdown:
```markdown
import a from 'b'
```
Yields:
```js
{
type: 'mdxjsEsm',
value: 'import a from \'b\''
}
```
### Content model
#### `FlowContent` (MDX.js ESM)
```idl
type FlowContentMdxjsEsm = MdxjsEsm | FlowContent
```
Note that when ESM is present, it can only exist as top-level content: if it has
a *[parent][dfn-parent]*, that parent must be **[Root][dfn-root]**.
## Types
This package is fully typed with [TypeScript][].
It exports the additional types [`MdxjsEsm`][api-mdxjs-esm] and
[`MdxjsEsmHast`][api-mdxjs-esm-hast].
It also registers the node type with `@types/mdast` and `@types/hast`.
If you’re working with the syntax tree, make sure to import this utility
somewhere in your types, as that registers the new node types in the tree.
```js
/**
* @typedef {import('mdast-util-mdxjs-esm')}
*/
import {visit} from 'unist-util-visit'
/** @type {import('mdast').Root} */
const tree = getMdastNodeSomeHow()
visit(tree, function (node) {
// `node` can now be an ESM node.
})
```
## 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-mdxjs-esm@^2`,
compatible with Node.js 16.
This utility works with `mdast-util-from-markdown` version 2+ and
`mdast-util-to-markdown` version 2+.
## Related
* [`remarkjs/remark-mdx`][remark-mdx]
— remark plugin to support MDX
* [`syntax-tree/mdast-util-mdx`][mdast-util-mdx]
— mdast utility to support MDX
* [`micromark/micromark-extension-mdxjs-esm`][extension]
— micromark extension to parse MDX.js ESM
## 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, organization, or community you agree to
abide by its terms.
## License
[MIT][license] © [Titus Wormer][author]
[build-badge]: https://github.com/syntax-tree/mdast-util-mdxjs-esm/workflows/main/badge.svg
[build]: https://github.com/syntax-tree/mdast-util-mdxjs-esm/actions
[coverage-badge]: https://img.shields.io/codecov/c/github/syntax-tree/mdast-util-mdxjs-esm.svg
[coverage]: https://codecov.io/github/syntax-tree/mdast-util-mdxjs-esm
[downloads-badge]: https://img.shields.io/npm/dm/mdast-util-mdxjs-esm.svg
[downloads]: https://www.npmjs.com/package/mdast-util-mdxjs-esm
[size-badge]: https://img.shields.io/badge/dynamic/json?label=minzipped%20size&query=$.size.compressedSize&url=https://deno.bundlejs.com/?q=mdast-util-mdxjs-esm
[size]: https://bundlejs.com/?q=mdast-util-mdxjs-esm
[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
[mdast-util-to-hast]: https://github.com/syntax-tree/mdast-util-to-hast
[mdast-util-from-markdown]: https://github.com/syntax-tree/mdast-util-from-markdown
[mdast-util-to-markdown]: https://github.com/syntax-tree/mdast-util-to-markdown
[mdast-util-mdx]: https://github.com/syntax-tree/mdast-util-mdx
[extension]: https://github.com/micromark/micromark-extension-mdxjs-esm
[syntax]: https://github.com/micromark/micromark-extension-mdxjs-esm#syntax
[program]: https://github.com/estree/estree/blob/master/es2015.md#programs
[dfn-literal]: https://github.com/syntax-tree/mdast#literal
[dfn-parent]: https://github.com/syntax-tree/unist#parent-1
[dfn-root]: https://github.com/syntax-tree/mdast#root
[remark-mdx]: https://mdxjs.com/packages/remark-mdx/
[mdx]: https://mdxjs.com
[from-markdown-extension]: https://github.com/syntax-tree/mdast-util-from-markdown#extension
[to-markdown-extension]: https://github.com/syntax-tree/mdast-util-to-markdown#options
[dfn-flow-content]: #flowcontent-mdxjs-esm
[api-mdxjs-esm-from-markdown]: #mdxjsesmfrommarkdown
[api-mdxjs-esm-to-markdown]: #mdxjsesmtomarkdown
[api-mdxjs-esm]: #mdxjsesm
[api-mdxjs-esm-hast]: #mdxjsesmhast