useArraySome

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

<Tabs> <TabItem label="JavaScript (and super languages)" icon="seti:javascript"> :::caution This rule is part of the [nursery](/linter/#nursery) group. This means that it is experimental and the behavior can change at any time. ::: ## Summary - Rule available since: `v2.4.5` - Diagnostic Category: [`lint/nursery/useArraySome`](/reference/diagnostics#diagnostic-category) - This rule has an [**unsafe**](/linter/#unsafe-fixes) fix. - The default severity of this rule is [**information**](/reference/diagnostics#information). - Sources: - Inspired from [`unicorn/prefer-array-some`](https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/prefer-array-some.md)

How to configure

json

{
	"linter": {
		"rules": {
			"nursery": {
				"useArraySome": "error"
			}
		}
	}
}

Description

Prefer Array.prototype.some() over verbose existence checks.

Examples

Invalid

array.filter(predicate).length > 0;

<pre class="language-text"><code class="language-text">code-block.js:1:1 <a href="https://biomejs.dev/linter/rules/use-array-some">lint/nursery/useArraySome</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Prefer .some() over filter(...).length comparison. > 1 │ array.filter(predicate).length > 0; │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2 │ ℹ Using .filter() followed by a length check iterates the entire array unnecessarily. .some() stops at the first match. ℹ Use .some() when you only need to know if any element matches. ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit <a href="https://biomejs.dev/linter/#nursery">https://biomejs.dev/linter/#nursery</a> for more information. ℹ Unsafe fix: Use .some() instead. 1 │ - array.filter(predicate).length·>·0; 1 │ + array.some(predicate); 2 2 │ </code></pre>

array.findIndex(predicate) !== -1;

<pre class="language-text"><code class="language-text">code-block.js:1:1 <a href="https://biomejs.dev/linter/rules/use-array-some">lint/nursery/useArraySome</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Prefer .some() over findIndex(...) !== -1. > 1 │ array.findIndex(predicate) !== -1; │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2 │ ℹ Use .some() when you only need to know if any element matches. ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit <a href="https://biomejs.dev/linter/#nursery">https://biomejs.dev/linter/#nursery</a> for more information. ℹ Unsafe fix: Use .some() instead. 1 │ - array.findIndex(predicate)·!==·-1; 1 │ + array.some(predicate); 2 2 │ </code></pre>

if (array.find(predicate)) {}

<pre class="language-text"><code class="language-text">code-block.js:1:5 <a href="https://biomejs.dev/linter/rules/use-array-some">lint/nursery/useArraySome</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Prefer .some() over find-family used as boolean. > 1 │ if (array.find(predicate)) {} │ ^^^^^^^^^^^^^^^^^^^^^ 2 │ ℹ Use .some() when you only need to know if any element matches. ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit <a href="https://biomejs.dev/linter/#nursery">https://biomejs.dev/linter/#nursery</a> for more information. </code></pre>

array.find(predicate) != null;

<pre class="language-text"><code class="language-text">code-block.js:1:1 <a href="https://biomejs.dev/linter/rules/use-array-some">lint/nursery/useArraySome</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Prefer .some() over find(...) existence comparison. > 1 │ array.find(predicate) != null; │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2 │ ℹ Use .some() when you only need to know if any element matches. ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit <a href="https://biomejs.dev/linter/#nursery">https://biomejs.dev/linter/#nursery</a> for more information. </code></pre>

array.findLastIndex(predicate) !== -1;

<pre class="language-text"><code class="language-text">code-block.js:1:1 <a href="https://biomejs.dev/linter/rules/use-array-some">lint/nursery/useArraySome</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Prefer .some() over findLastIndex(...) !== -1. > 1 │ array.findLastIndex(predicate) !== -1; │ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 2 │ ℹ Use .some() when you only need to know if any element matches. ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit <a href="https://biomejs.dev/linter/#nursery">https://biomejs.dev/linter/#nursery</a> for more information. ℹ Unsafe fix: Use .some() instead. 1 │ - array.findLastIndex(predicate)·!==·-1; 1 │ + array.some(predicate); 2 2 │ </code></pre>

if (array.findLast(predicate)) {}

<pre class="language-text"><code class="language-text">code-block.js:1:5 <a href="https://biomejs.dev/linter/rules/use-array-some">lint/nursery/useArraySome</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ℹ Prefer .some() over find-family used as boolean. > 1 │ if (array.findLast(predicate)) {} │ ^^^^^^^^^^^^^^^^^^^^^^^^^ 2 │ ℹ Use .some() when you only need to know if any element matches. ℹ This rule belongs to the nursery group, which means it is not yet stable and may change in the future. Visit <a href="https://biomejs.dev/linter/#nursery">https://biomejs.dev/linter/#nursery</a> for more information. </code></pre>

Valid

array.some(predicate);

</TabItem> </Tabs>

How to configure

Description

Examples

Invalid

Valid

Related links