remark-lint-heading-style
remark-lint
rule to warn when headings violate a given style.
Contents
- What is this?
- When should I use this?
- Presets
- Install
- Use
- API
- Recommendation
- Fix
- 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 headings are consistent.
Presets
This rule is included in the following presets:
Preset | Setting |
---|---|
remark-preset-lint-consistent | 'consistent' |
remark-preset-lint-markdown-style-guide | 'atx' |
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-style
In Deno with esm.sh
:
import remarkLintHeadingStyle from 'https://esm.sh/remark-lint-heading-style@3'
In browsers with esm.sh
:
<script type="module">
import remarkLintHeadingStyle from 'https://esm.sh/remark-lint-heading-style@3?bundle'
</script>
Use
On the API:
import {remark} from 'remark'
import remarkLint from 'remark-lint'
import remarkLintHeadingStyle from 'remark-lint-heading-style'
import {read} from 'to-vfile'
import {reporter} from 'vfile-reporter'
const file = await read('example.md')
await remark()
.use(remarkLint)
.use(remarkLintHeadingStyle)
.process(file)
console.error(reporter(file))
On the CLI:
remark --use remark-lint --use remark-lint-heading-style example.md
On the CLI in a config file (here a package.json
):
…
"remarkConfig": {
"plugins": [
…
"remark-lint",
+ "remark-lint-heading-style",
…
]
}
…
API
This package exports no identifiers. The default export is remarkLintHeadingStyle
.
unified().use(remarkLintHeadingStyle[, 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).
The following options (default: 'consistent'
) are accepted:
'atx'
— prefer ATX headings:## Hello
'atx-closed'
— prefer ATX headings with a closing sequence:## Hello ##
'setext'
— prefer setext headings:Hello -----
'consistent'
— detect the first used style and warn when further headings differ
Recommendation
Setext headings are limited in that they can only construct headings with a rank of one and two. On the other hand, they do allow multiple lines of content whereas ATX only allows one line. The number of used markers in their underline does not matter, leading to either:
- 1 marker (
Hello\n-
), which is the bare minimum, and for rank 2 headings looks suspiciously like an empty list item - using as many markers as the content (
Hello\n-----
), which is hard to maintain - an arbitrary number (
Hello\n---
), which for rank 2 headings looks suspiciously like a thematic break
Setext headings are also rather uncommon. Using a sequence of hashes at the end of ATX headings is even more uncommon. Due to this, it’s recommended to prefer ATX headings.
Fix
remark-stringify
formats headings as ATX by default. The other styles can be configured with setext: true
or closeAtx: true
.
Examples
ok.md
When configured with 'atx'
.
In
# Alpha
## Bravo
### Charlie
Out
No messages.
ok.md
When configured with 'atx-closed'
.
In
# Delta ##
## Echo ##
### Foxtrot ###
Out
No messages.
ok.md
When configured with 'setext'
.
In
Golf
====
Hotel
-----
### India
Out
No messages.
not-ok.md
In
Juliett
=======
## Kilo
### Lima ###
Out
4:1-4:8: Headings should use setext
6:1-6:13: Headings should use setext
not-ok.md
When configured with '💩'
.
Out
1:1: Incorrect heading style type `💩`: use either `'consistent'`, `'atx'`, `'atx-closed'`, or `'setext'`
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.