unified

Project: remarkjs/remark-lint

Package: remark-lint-no-tabs@3.1.1

  1. Dependents: 0
  2. remark-lint rule to warn when hard tabs are used instead of spaces
  1. remark 193
  2. lint 76
  3. rule 72
  4. remark-lint-rule 65

remark-lint-no-tabs

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remark-lint rule to warn when tabs are used.

Contents

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 tabs are not used.

Presets

This rule is not included in a preset maintained here.

Install

This package is ESM only. In Node.js (version 12.20+, 14.14+, or 16.0+), install with npm:

npm install remark-lint-no-tabs

In Deno with esm.sh:

import remarkLintNoTabs from 'https://esm.sh/remark-lint-no-tabs@3'

In browsers with esm.sh:

<script type="module">
  import remarkLintNoTabs from 'https://esm.sh/remark-lint-no-tabs@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 remarkLintNoTabs from 'remark-lint-no-tabs'

main()

async function main() {
  const file = await remark()
    .use(remarkLint)
    .use(remarkLintNoTabs)
    .process(await read('example.md'))

  console.error(reporter(file))
}

On the CLI:

remark --use remark-lint --use remark-lint-no-tabs example.md

On the CLI in a config file (here a package.json):

 …
 "remarkConfig": {
   "plugins": [
     …
     "remark-lint",
+    "remark-lint-no-tabs",
     …
   ]
 }
 …

API

This package exports no identifiers. The default export is remarkLintNoTabs.

unified().use(remarkLintNoTabs[, 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

Regardless of the debate in other languages of whether to use tabs vs. spaces, when it comes to markdown, tabs do not work as expected. Largely around contains such as block quotes and lists. Take for example block quotes: >\ta gives a paragraph with the text a in a blockquote, so one might expect that >\t\ta results in indented code with the text a in a block quote.

>\ta

>\t\ta

Yields:

<blockquote>
<p>a</p>
</blockquote>
<blockquote>
<pre><code>  a
</code></pre>
</blockquote>

Because markdown uses a hardcoded tab size of 4, the first tab could be represented as 3 spaces (because there’s a > before). One of those “spaces” is taken because block quotes allow the > to be followed by one space, leaving 2 spaces. The next tab can be represented as 4 spaces, so together we have 6 spaces. The indented code uses 4 spaces, so there are two spaces left, which are shown in the indented code.

Fix

remark-stringify uses spaces exclusively for indentation.

Examples

ok.md
In

👉 Note: · represents a space.

Foo Bar

····Foo
Out

No messages.

not-ok.md
In

👉 Note: » represents a tab.

»Here's one before a code block.

Here's a tab:», and here is another:».

And this is in `inline»code`.

>»This is in a block quote.

*»And…

»1.»in a list.

And this is a tab as the last character.»
Out
1:1: Use spaces instead of tabs
3:14: Use spaces instead of tabs
3:37: Use spaces instead of tabs
5:23: Use spaces instead of tabs
7:2: Use spaces instead of tabs
9:2: Use spaces instead of tabs
11:1: Use spaces instead of tabs
11:4: Use spaces instead of tabs
13:41: Use spaces instead of tabs

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.

License

MIT © Titus Wormer