ContextQMD
Back to Biomejs

noUselessLabel

src/content/docs/linter/rules/no-useless-label.mdx

latest3.6 KB
Original Source

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

<Tabs> <TabItem label="JavaScript (and super languages)" icon="seti:javascript"> ## Summary - Rule available since: `v1.0.0` - Diagnostic Category: [`lint/complexity/noUselessLabel`](/reference/diagnostics#diagnostic-category) - This rule is **recommended**, meaning it is enabled by default. - This rule has a [**safe**](/linter/#safe-fixes) fix. - The default severity of this rule is [**information**](/reference/diagnostics#information). - Sources: - Same as [`no-extra-label`](https://eslint.org/docs/latest/rules/no-extra-label)

How to configure

json
{
	"linter": {
		"rules": {
			"complexity": {
				"noUselessLabel": "error"
			}
		}
	}
}

Description

Disallow unnecessary labels.

If a loop contains no nested loops or switches, labeling the loop is unnecessary.

Examples

Invalid

js
loop: while(a) {
    break loop;
}
<pre class="language-text"><code class="language-text">code-block.js:2:11 <a href="https://biomejs.dev/linter/rules/no-useless-label">lint/complexity/noUselessLabel</a> <span style="color: #000; background-color: #ddd;"> FIXABLE </span> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Unnecessary </span><span style="color: lightgreen;"><strong>label</strong></span><span style="color: lightgreen;">.</span> <strong>1 │ </strong>loop: while(a) &#123; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>2 │ </strong> break loop; <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>3 │ </strong>&#125; <strong>4 │ </strong> <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Safe fix</span><span style="color: lightgreen;">: </span><span style="color: lightgreen;">Remove the unnecessary </span><span style="color: lightgreen;"><strong>label</strong></span><span style="color: lightgreen;">. </span> <span style="color: lightgreen;">You can achieve the same result without the label.</span> <strong> 2 │ </strong><span style="opacity: 0.8;">·</span><span style="opacity: 0.8;">·</span><span style="opacity: 0.8;">·</span><span style="opacity: 0.8;">·</span>break<span style="opacity: 0.8;"><span style="color: Tomato;">·</span></span><span style="color: Tomato;">l</span><span style="color: Tomato;">o</span><span style="color: Tomato;">o</span><span style="color: Tomato;">p</span>; <strong> │ </strong> <span style="color: Tomato;">-</span><span style="color: Tomato;">-</span><span style="color: Tomato;">-</span><span style="color: Tomato;">-</span><span style="color: Tomato;">-</span> </code></pre>

Valid

js
outer: while(a) {
    while(b) {
        break outer;
    }
}
</TabItem> </Tabs>