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noEmptyPattern

src/content/docs/linter/rules/no-empty-pattern.mdx

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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/correctness/noEmptyPattern`](/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 [`no-empty-pattern`](https://eslint.org/docs/latest/rules/no-empty-pattern)

How to configure

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

Description

Disallows empty destructuring patterns.

Examples

Invalid

js
var {} = foo;
<pre class="language-text"><code class="language-text">code-block.js:1:5 <a href="https://biomejs.dev/linter/rules/no-empty-pattern">lint/correctness/noEmptyPattern</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">Unexpected empty object pattern.</span> <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>var &#123;&#125; = foo; <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>2 │ </strong> </code></pre>
js
var {a: {}} = foo;
<pre class="language-text"><code class="language-text">code-block.js:1:9 <a href="https://biomejs.dev/linter/rules/no-empty-pattern">lint/correctness/noEmptyPattern</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">Unexpected empty object pattern.</span> <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>var &#123;a: &#123;&#125;&#125; = foo; <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>2 │ </strong> </code></pre>
js
function foo({}) {}
<pre class="language-text"><code class="language-text">code-block.js:1:14 <a href="https://biomejs.dev/linter/rules/no-empty-pattern">lint/correctness/noEmptyPattern</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">Unexpected empty object pattern.</span> <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>function foo(&#123;&#125;) &#123;&#125; <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>2 │ </strong> </code></pre>

Valid

The following cases are valid because they create new bindings.

js
var {a = {}} = foo;
var {a, b = {}} = foo;
var {a = []} = foo;
function foo({a = {}}) {}
function foo({a = []}) {}
var [a] = foo;
</TabItem> </Tabs>