ContextQMD
Back to Biomejs

noUnknownPseudoClass

src/content/docs/linter/rules/no-unknown-pseudo-class.mdx

latest6.2 KB
Original Source

import { Tabs, TabItem } from '@astrojs/starlight/components';

<Tabs> <TabItem label="CSS" icon="seti:css"> ## Summary - Rule available since: `v1.8.0` - Diagnostic Category: [`lint/correctness/noUnknownPseudoClass`](/reference/diagnostics#diagnostic-category) - This rule is **recommended**, meaning it is enabled by default. - This rule doesn't have a fix. - The default severity of this rule is [**error**](/reference/diagnostics#error). - Sources: - Same as [`selector-pseudo-class-no-unknown`](https://github.com/stylelint/stylelint/blob/main/lib/rules/selector-pseudo-class-no-unknown/README.md)

How to configure

json
{
	"linter": {
		"rules": {
			"correctness": {
				"noUnknownPseudoClass": "error"
			}
		}
	}
}

Description

Disallow unknown pseudo-class selectors.

For details on known pseudo-class, see the MDN web docs

This rule ignores vendor-prefixed pseudo-class selectors.

Examples

Invalid

css
a:unknown {}
<pre class="language-text"><code class="language-text">code-block.css:1:3 <a href="https://biomejs.dev/linter/rules/no-unknown-pseudo-class">lint/correctness/noUnknownPseudoClass</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">Unexpected unknown pseudo-class </span><span style="color: Tomato;"><strong>unknown</strong></span><span style="color: Tomato;"> </span> <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>a:unknown &#123;&#125; <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>2 │ </strong> <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">See </span><span style="color: lightgreen;"><a href="https://developer.mozilla.org/en-US/docs/Web/CSS/Pseudo-classes">MDN web docs</a></span><span style="color: lightgreen;"> for more details.</span> </code></pre>
css
a:UNKNOWN {}
<pre class="language-text"><code class="language-text">code-block.css:1:3 <a href="https://biomejs.dev/linter/rules/no-unknown-pseudo-class">lint/correctness/noUnknownPseudoClass</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">Unexpected unknown pseudo-class </span><span style="color: Tomato;"><strong>UNKNOWN</strong></span><span style="color: Tomato;"> </span> <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>a:UNKNOWN &#123;&#125; <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>2 │ </strong> <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">See </span><span style="color: lightgreen;"><a href="https://developer.mozilla.org/en-US/docs/Web/CSS/Pseudo-classes">MDN web docs</a></span><span style="color: lightgreen;"> for more details.</span> </code></pre>
css
a:hoverr {}
<pre class="language-text"><code class="language-text">code-block.css:1:3 <a href="https://biomejs.dev/linter/rules/no-unknown-pseudo-class">lint/correctness/noUnknownPseudoClass</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">Unexpected unknown pseudo-class </span><span style="color: Tomato;"><strong>hoverr</strong></span><span style="color: Tomato;"> </span> <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>a:hoverr &#123;&#125; <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>2 │ </strong> <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">See </span><span style="color: lightgreen;"><a href="https://developer.mozilla.org/en-US/docs/Web/CSS/Pseudo-classes">MDN web docs</a></span><span style="color: lightgreen;"> for more details.</span> </code></pre>

Valid

css
a:hover {}
css
a:focus {}
css
:not(p) {}
css
input:-moz-placeholder {}

Options

ignore

A list of unknown pseudo-class names to ignore (case-insensitive).

json
{
	"linter": {
		"rules": {
			"correctness": {
				"noUnknownPseudoClass": {
					"options": {
						"ignore": [
							"custom-pseudo-class"
						]
					}
				}
			}
		}
	}
}

Valid

css
a:custom-pseudo-class {}
</TabItem> </Tabs>