remark-lint-heading-increment
remark-lint
rule to warn when heading ranks increment with more than 1 at a time.
Contents
- What is this?
- When should I use this?
- Presets
- Install
- Use
- API
- Recommendation
- Examples
- Compatibility
- Contribute
- License
What is this?
This package is a unified (remark) plugin, specifically a remark-lint
rule. Lint rules check markdown code style.
When should I use this?
You can use this package to check that heading ranks increment with one at a time.
Presets
This rule is included in the following presets:
Preset | Setting |
---|---|
remark-preset-lint-markdown-style-guide |
Install
This package is ESM only. In Node.js (version 12.20+, 14.14+, or 16.0+), install with npm:
npm install remark-lint-heading-increment
In Deno with esm.sh
:
import remarkLintHeadingIncrement from 'https://esm.sh/remark-lint-heading-increment@3'
In browsers with esm.sh
:
<script type="module">
import remarkLintHeadingIncrement from 'https://esm.sh/remark-lint-heading-increment@3?bundle'
</script>
Use
On the API:
import {read} from 'to-vfile'
import {reporter} from 'vfile-reporter'
import {remark} from 'remark'
import remarkLint from 'remark-lint'
import remarkLintHeadingIncrement from 'remark-lint-heading-increment'
main()
async function main() {
const file = await remark()
.use(remarkLint)
.use(remarkLintHeadingIncrement)
.process(await read('example.md'))
console.error(reporter(file))
}
On the CLI:
remark --use remark-lint --use remark-lint-heading-increment example.md
On the CLI in a config file (here a package.json
):
…
"remarkConfig": {
"plugins": [
…
"remark-lint",
+ "remark-lint-heading-increment",
…
]
}
…
API
This package exports no identifiers. The default export is remarkLintHeadingIncrement
.
unified().use(remarkLintHeadingIncrement[, config])
This rule supports standard configuration that all remark lint rules accept (such as false
to turn it off or [1, options]
to configure it).
There are no options.
Recommendation
While markdown is not only used for HTML, HTML accessibility guidelines state that headings should increment by one at a time. As in, say the previous heading had a rank of 2 (so <h2>
), then the following heading that is to be considered “inside” it should have a rank of 3 (<h3>
). Due to this, it’s recommended that when HTML output is a goal of the document, that this rule is turned on.
Examples
ok.md
In
# Alpha
## Bravo
Out
No messages.
not-ok.md
In
# Charlie
### Delta
Out
3:1-3:10: Heading levels should increment by one level at a time
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.
Contribute
See contributing.md
in remarkjs/.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, organization, or community you agree to abide by its terms.