An opinionated collection of markdownlint rules used by GitHub.
npm install @github/markdownlint-githubThis repository provides GitHub's recommended markdownlint configurations, and additional rules for use on GitHub open source and internal projects.
In addition to defaults defined by markdownlint, we use this repository to enforce rules not defined by default, including our own custom rules.
See opinions codified in index.js.
The following are custom rules defined in this plugin.
* GH001 _no-default-alt-text_
* GH002 _no-generic-link-text_
* GH003 _no-empty-alt-text_
See markdownlint rules for documentation on rules pulled in from markdownlint.
Important: We support the use of markdownlint through markdownlint-cli2 instead of markdownlint-cli for compatibility with the vscode-markdownlint plugin.
1. Create a .markdownlint-cli2.mjs file in the root of your repository.
``bash`
touch .markdownlint-cli2.mjs
2. Install packages.
`bash`
npm install -D markdownlint-cli2 # if updating existing package, check for updates
npm install -D @github/markdownlint-github [--@github:registry=https://registry.npmjs.org]
npm install -D markdownlint-cli2-formatter-pretty
3. Add/modify your linting script in package.json.
`json`
"scripts": {
"lint:markdown": "markdownlint-cli2 \"*/.{md,mdx}\" \"!node_modules\""
}
4. Edit .markdownlint-cli2.mjs file to suit your needs. Start with
`js`
import configOptions, {init} from "@github/markdownlint-github"
const options = {
config: init(),
customRules: ["@github/markdownlint-github"],
outputFormatters: [
[ "markdownlint-cli2-formatter-pretty", { "appendLink": true } ] // ensures the error message includes a link to the rule documentation
]
}
export default options
Or, you can also pass in configuration options that you wish to override the default. Read more at Customizing configurations.
This looks like:
`js`
import configOptions, {init} from "@github/markdownlint-github"
const overriddenOptions = init({
'fenced-code-language': false, // Custom overrides
})
const options = {
config: overriddenOptions,
customRules: ["@github/markdownlint-github"],
outputFormatters: [
[ "markdownlint-cli2-formatter-pretty", { "appendLink": true } ]
]
}
export default options
5. Install the vscode-markdownlint plugin to ensure markdownlint violations are surfaced in the file. This plugin should flag rules based off your .markdownlint-cli2.mjs configuration. When you make edits to your configuration, you will need to reload the VSCode window (Ctrl+Shift+P -> Reload Window) to ensure the extension syncs. If your project runs on Codespaces, consider adding this extension to your .devcontainer/devcontainer.json so that this extension is installed to new Codespaces by default.
You may determine that the defaults set by this plugin are not suitable for your project.
This plugin will pull in the the defaults defined by markdownlint, several of which pertain to stylistic practices. You may choose to disable these rules if you determine it doesn't provide value for your project.
However, others of these rules should NOT be disabled because they encourage best accessibility practices. Disabling these rules will negatively impact accessibility. These rules are defined in accessibility.json.
To review configurations supported by markdownlint, see markdownlint-cli2 configuration.
You may write custom rules within your repository. Follow the custom rules guide in markdownlint to write your rule.
The rule will need to be enabled in the configuration. For instance, if you introduce some-rule.js with the name "some-rule", you must set the path of the custom rule in the .markdownlint-cli2.mjs file:
`js`
import configOptions, {init} from "@github/markdownlint-github"
const options = init({
"some-rule": true,
customRules: ["@github/markdownlint-github", "some-rule.js"],
})
export default options
See markdownlint-cli2` configuration.
Consider upstreaming any rules you find useful as proposals to this repository.
This project is licensed under the terms of the MIT open source license. Please
refer to the MIT license for the full terms.
See CODEOWNERS.
Please read Contributing Guide for more information.