# remark-github
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[**remark**][remark] plugin to link references to commits, issues, and users,
in the same way that GitHub does in comments, issues, PRs, and releases (see
[Writing on GitHub][writing-on-github]).
## Contents
* [What is this?](#what-is-this)
* [When should I use this?](#when-should-i-use-this)
* [Install](#install)
* [Use](#use)
* [API](#api)
* [`unified().use(remarkGithub[, options])`](#unifieduseremarkgithub-options)
* [Examples](#examples)
* [Example: `buildUrl`](#example-buildurl)
* [Syntax](#syntax)
* [Types](#types)
* [Compatibility](#compatibility)
* [Security](#security)
* [Related](#related)
* [Contribute](#contribute)
* [License](#license)
## What is this?
This package is a [unified][] ([remark][]) plugin to link references to commits,
issues, and users: `@wooorm` -> `[**@wooorm**](https://github.com/wooorm)`.
**unified** is a project that transforms content with abstract syntax trees
(ASTs).
**remark** adds support for markdown to unified.
**mdast** is the markdown AST that remark uses.
This is a remark plugin that transforms mdast.
## When should I use this?
This project is useful if you want to emulate how markdown would work in GitHub
comments, issues, PRs, or releases, but it’s actually displayed somewhere else
(on a website, or in other places on GitHub which don’t link references, such as
markdown in a repo or Gist).
This plugin does not support other platforms such as GitLab or Bitbucket and
their custom features.
A different plugin, [`remark-gfm`][remark-gfm], adds support for GFM (GitHub
Flavored Markdown).
GFM is a set of extensions (autolink literals, footnotes, strikethrough, tables,
and tasklists) to markdown that are supported everywhere on GitHub.
Another plugin, [`remark-breaks`][remark-breaks], turns soft line endings
(enters) into hard breaks (`<br>`s).
GitHub does this in a few places (comments, issues, PRs, and releases), but it’s
not semantic according to HTML and not compliant to markdown.
Yet another plugin, [`remark-frontmatter`][remark-frontmatter], adds support
for YAML frontmatter.
GitHub supports frontmatter for files in Gists and repos.
## Install
This package is [ESM only](https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c).
In Node.js (version 12.20+, 14.14+, or 16.0+), install with [npm][]:
```sh
npm install remark-github
```
In Deno with [`esm.sh`][esmsh]:
```js
import remarkGithub from 'https://esm.sh/remark-github@11'
```
In browsers with [`esm.sh`][esmsh]:
```html
<script type="module">
import remarkGithub from 'https://esm.sh/remark-github@11?bundle'
</script>
```
## Use
Say we have the following file, `example.md`:
```markdown
Some references:
* Commit: f8083175fe890cbf14f41d0a06e7aa35d4989587
* Commit (fork): foo@f8083175fe890cbf14f41d0a06e7aa35d4989587
* Commit (repo): remarkjs/remark@e1aa9f6c02de18b9459b7d269712bcb50183ce89
* Issue or PR (`#`): #1
* Issue or PR (`GH-`): GH-1
* Issue or PR (fork): foo#1
* Issue or PR (project): remarkjs/remark#1
* Mention: @wooorm
Some links:
* Commit: <https://github.com/remarkjs/remark/commit/e1aa9f6c02de18b9459b7d269712bcb50183ce89>
* Commit comment: <https://github.com/remarkjs/remark/commit/ac63bc3abacf14cf08ca5e2d8f1f8e88a7b9015c#commitcomment-16372693>
* Issue or PR: <https://github.com/remarkjs/remark/issues/182>
* Issue or PR comment: <https://github.com/remarkjs/remark-github/issues/3#issue-151160339>
* Mention: <https://github.com/ben-eb>
```
And our module, `example.js`, looks as follows:
```js
import {read} from 'to-vfile'
import {remark} from 'remark'
import remarkGfm from 'remark-gfm'
import remarkGithub from 'remark-github'
const file = await remark()
.use(remarkGfm)
.use(remarkGithub)
.process(await read('example.md'))
console.log(String(file))
```
Now, running `node example` yields:
```markdown
Some references:
* Commit: [`f808317`](https://github.com/remarkjs/remark-github/commit/f8083175fe890cbf14f41d0a06e7aa35d4989587)
* Commit (fork): [foo@`f808317`](https://github.com/foo/remark-github/commit/f8083175fe890cbf14f41d0a06e7aa35d4989587)
* Commit (repo): [remarkjs/remark@`e1aa9f6`](https://github.com/remarkjs/remark/commit/e1aa9f6c02de18b9459b7d269712bcb50183ce89)
* Issue or PR (`#`): [#1](https://github.com/remarkjs/remark-github/issues/1)
* Issue or PR (`GH-`): [GH-1](https://github.com/remarkjs/remark-github/issues/1)
* Issue or PR (fork): [foo#1](https://github.com/foo/remark-github/issues/1)
* Issue or PR (project): [remarkjs/remark#1](https://github.com/remarkjs/remark/issues/1)
* Mention: [**@wooorm**](https://github.com/wooorm)
Some links:
* Commit: [remarkjs/remark@`e1aa9f6`](https://github.com/remarkjs/remark/commit/e1aa9f6c02de18b9459b7d269712bcb50183ce89)
* Commit comment: [remarkjs/remark@`ac63bc3` (comment)](https://github.com/remarkjs/remark/commit/ac63bc3abacf14cf08ca5e2d8f1f8e88a7b9015c#commitcomment-16372693)
* Issue or PR: [remarkjs/remark#182](https://github.com/remarkjs/remark/issues/182)
* Issue or PR comment: [#3 (comment)](https://github.com/remarkjs/remark-github/issues/3#issue-151160339)
* Mention: <https://github.com/ben-eb>
```
## API
This package exports no identifiers.
The default export is `remarkGithub`.
### `unified().use(remarkGithub[, options])`
Link references to users, commits, and issues, in the same way that GitHub does
in comments, issues, PRs, and releases (see
[Writing on GitHub][writing-on-github]).
##### `options`
Configuration (optional).
###### `options.repository`
Repository to link against (`string`, optional).
Detected in Node.js from the `repository` field in `package.json` if not given.
Should point to a GitHub repository, such as
`'https://github.com/user/project.git'` or `'user/project'`.
###### `options.mentionStrong`
Wrap mentions in `strong` (`boolean`, default: `true`).
This makes them render more like how GitHub styles them.
But GitHub itself uses CSS instead of strong.
###### `options.buildUrl`
Change how (and whether) things are linked (`Function`, optional).
This can be used to point links to GitHub Enterprise or other places.
It’s called with the following parameters:
* `values` (`BuildUrlValues`)
— info on the link to build
* `defaultBuildUrl` (`(values: BuildUrlValues) => string`)
— function that can be called to perform normal behavior
It should return the URL to use (`string`) or `false` to not create a link.
The following schemas are passed as `BuildUrlValues`:
* `{type: 'commit', user, project, hash}`
* `{type: 'compare', user, project, base, compare}`
* `{type: 'issue', user, project, no}`
* `{type: 'mention', user}`
## Examples
### Example: `buildUrl`
A `buildUrl` can be passed to not link mentions.
For example, by changing `example.js` from before like so:
```diff
@@ -8,7 +8,11 @@ main()
async function main() {
const file = await remark()
.use(remarkGfm)
- .use(remarkGithub)
+ .use(remarkGithub, {
+ buildUrl(values, defaultBuildUrl) {
+ return values.type === 'mention' ? false : defaultBuildUrl(values)
+ }
+ })
.process(await read('example.md'))
console.log(String(file))
```
To instead point mentions to a different place, change `example.js` like so:
```diff
@@ -8,7 +8,13 @@ main()
async function main() {
const file = await remark()
.use(remarkGfm)
- .use(remarkGithub)
+ .use(remarkGithub, {
+ buildUrl(values, defaultBuildUrl) {
+ return values.type === 'mention'
+ ? `https://yourwebsite.com/${values.user}/`
+ : defaultBuildUrl(values)
+ }
+ })
.process(await read('example.md'))
console.log(String(file))
```
## Syntax
The following references are supported:
* Commits:
`1f2a4fb` → [`1f2a4fb`][sha]
* Commits across forks:
`remarkjs@1f2a4fb` → [remarkjs@`1f2a4fb`][sha]
* Commits across projects:
`remarkjs/remark-github@1f2a4fb` → [remarkjs/remark-github@`1f2a4fb`][sha]
* Compare ranges:
`e2acebc...2aa9311` →
[`e2acebc...2aa9311`][sha-range]
* Compare ranges across forks:
`remarkjs@e2acebc...2aa9311` →
[remarkjs/remark-github@`e2acebc...2aa9311`][sha-range]
* Compare ranges across projects:
`remarkjs/remark-github@e2acebc...2aa9311` →
[remarkjs/remark-github@`e2acebc...2aa9311`][sha-range]
* Prefix issues:
`GH-1` → [GH-1][issue]
* Hash issues:
`#1` → [#1][issue]
* Issues across forks:
`remarkjs#1` → [remarkjs#1][issue]
* Issues across projects:
`remarkjs/remark-github#1` → [remarkjs/remark-github#1][issue]
* At-mentions:
`@wooorm` → [**@wooorm**][mention]
Autolinks to these references are also transformed:
`https://github.com/wooorm` -> `[**@wooorm**](https://github.com/wooorm)`
## Types
This package is fully typed with [TypeScript][].
It exports an `Options` type, which specifies the interface of the accepted
options.
There are also `BuildUrl`, `BuildUrlValues`, `BuildUrlCommitValues`,
`BuildUrlCompareValues`, `BuildUrlIssueValues`, `BuildUrlMentionValues`,
and `DefaultBuildUrl` types exported.
## Compatibility
Projects maintained by the unified collective are compatible with all maintained
versions of Node.js.
As of now, that is Node.js 12.20+, 14.14+, and 16.0+.
Our projects sometimes work with older versions, but this is not guaranteed.
This plugin works with `unified` version 6+ and `remark` version 7+.
## Security
Use of `remark-github` does not involve [**rehype**][rehype] ([**hast**][hast]).
It does inject links based on user content, but those links only go to GitHub.
There are no openings for [cross-site scripting (XSS)][xss] attacks.
## Related
* [`remark-gfm`][remark-gfm]
— support GFM (autolink literals, footnotes, strikethrough, tables,
tasklists)
* [`remark-breaks`][remark-breaks]
— support breaks without needing spaces or escapes (enters to `<br>`)
* [`remark-frontmatter`][remark-frontmatter]
— support frontmatter (YAML, TOML, and more)
## Contribute
See [`contributing.md`][contributing] in [`remarkjs/.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]
<!-- Definitions -->
[build-badge]: https://github.com/remarkjs/remark-github/workflows/main/badge.svg
[build]: https://github.com/remarkjs/remark-github/actions
[coverage-badge]: https://img.shields.io/codecov/c/github/remarkjs/remark-github.svg
[coverage]: https://codecov.io/github/remarkjs/remark-github
[downloads-badge]: https://img.shields.io/npm/dm/remark-github.svg
[downloads]: https://www.npmjs.com/package/remark-github
[size-badge]: https://img.shields.io/bundlephobia/minzip/remark-github.svg
[size]: https://bundlephobia.com/result?p=remark-github
[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/remarkjs/remark/discussions
[npm]: https://docs.npmjs.com/cli/install
[esmsh]: https://esm.sh
[health]: https://github.com/remarkjs/.github
[contributing]: https://github.com/remarkjs/.github/blob/HEAD/contributing.md
[support]: https://github.com/remarkjs/.github/blob/HEAD/support.md
[coc]: https://github.com/remarkjs/.github/blob/HEAD/code-of-conduct.md
[license]: license
[author]: https://wooorm.com
[remark]: https://github.com/remarkjs/remark
[unified]: https://github.com/unifiedjs/unified
[writing-on-github]: https://docs.github.com/en/github/writing-on-github#references
[sha]: https://github.com/remarkjs/remark-github/commit/1f2a4fb8f88a0a98ea9d0c0522cd538a9898f921
[sha-range]: https://github.com/wooorm/remark/compare/e2acebc...2aa9311
[issue]: https://github.com/remarkjs/remark-github/issues/1
[mention]: https://github.com/wooorm
[xss]: https://en.wikipedia.org/wiki/Cross-site_scripting
[typescript]: https://www.typescriptlang.org
[rehype]: https://github.com/rehypejs/rehype
[hast]: https://github.com/syntax-tree/hast
[remark-gfm]: https://github.com/remarkjs/remark-gfm
[remark-breaks]: https://github.com/remarkjs/remark-breaks
[remark-frontmatter]: https://github.com/remarkjs/remark-frontmatter