useBlockStatements

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/style/useBlockStatements`](/reference/diagnostics#diagnostic-category) - This rule isn't recommended, so you need to enable it. - This rule has an [**unsafe**](/linter/#unsafe-fixes) fix. - The default severity of this rule is [**warning**](/reference/diagnostics#warning). - Sources: - Same as [`curly`](https://eslint.org/docs/latest/rules/curly)

How to configure

json

{
	"linter": {
		"rules": {
			"style": {
				"useBlockStatements": "error"
			}
		}
	}
}

Description

Requires following curly brace conventions.

JavaScript allows the omission of curly braces when a block contains only one statement. However, it is considered by many to be best practice to never omit curly braces around blocks, even when they are optional, because it can lead to bugs and reduces code clarity.

Examples

Invalid

 if (x) x;

<pre class="language-text"><code class="language-text">code-block.js:1:2 <a href="https://biomejs.dev/linter/rules/use-block-statements">lint/style/useBlockStatements</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Block statements are preferred in this position. > 1 │ if (x) x; │ ^^^^^^^^^ 2 │ ℹ Unsafe fix: Wrap the statement with a `JsBlockStatement` 1 │ ·if·(x)·{·x;·} │ ++ ++ </code></pre>

 if (x) {
   x;
 } else y;

<pre class="language-text"><code class="language-text">code-block.js:3:4 <a href="https://biomejs.dev/linter/rules/use-block-statements">lint/style/useBlockStatements</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Block statements are preferred in this position. 1 │ if (x) { 2 │ x; > 3 │ } else y; │ ^^^^^^^ 4 │ ℹ Unsafe fix: Wrap the statement with a `JsBlockStatement` 3 │ ·}·else·{·y;·} │ ++ ++ </code></pre>

if (x) {
  x;
} else if (y) y;

<pre class="language-text"><code class="language-text">code-block.js:3:8 <a href="https://biomejs.dev/linter/rules/use-block-statements">lint/style/useBlockStatements</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Block statements are preferred in this position. 1 │ if (x) { 2 │ x; > 3 │ } else if (y) y; │ ^^^^^^^^^ 4 │ ℹ Unsafe fix: Wrap the statement with a `JsBlockStatement` 3 │ }·else·if·(y)·{·y;·} │ ++ ++ </code></pre>

   for (;;);

<pre class="language-text"><code class="language-text">code-block.js:1:4 <a href="https://biomejs.dev/linter/rules/use-block-statements">lint/style/useBlockStatements</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Block statements are preferred in this position. > 1 │ for (;;); │ ^^^^^^^^^ 2 │ ℹ Unsafe fix: Wrap the statement with a `JsBlockStatement` 1 │ - ···for·(;;); 1 │ + ···for·(;;)·{} 2 2 │ </code></pre>

   for (p in obj);

<pre class="language-text"><code class="language-text">code-block.js:1:4 <a href="https://biomejs.dev/linter/rules/use-block-statements">lint/style/useBlockStatements</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Block statements are preferred in this position. > 1 │ for (p in obj); │ ^^^^^^^^^^^^^^^ 2 │ ℹ Unsafe fix: Wrap the statement with a `JsBlockStatement` 1 │ - ···for·(p·in·obj); 1 │ + ···for·(p·in·obj)·{} 2 2 │ </code></pre>

  for (x of xs);

<pre class="language-text"><code class="language-text">code-block.js:1:3 <a href="https://biomejs.dev/linter/rules/use-block-statements">lint/style/useBlockStatements</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Block statements are preferred in this position. > 1 │ for (x of xs); │ ^^^^^^^^^^^^^^ 2 │ ℹ Unsafe fix: Wrap the statement with a `JsBlockStatement` 1 │ - ··for·(x·of·xs); 1 │ + ··for·(x·of·xs)·{} 2 2 │ </code></pre>

  do;
  while (x);

<pre class="language-text"><code class="language-text">code-block.js:1:3 <a href="https://biomejs.dev/linter/rules/use-block-statements">lint/style/useBlockStatements</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Block statements are preferred in this position. > 1 │ do; │ ^^^ > 2 │ while (x); │ ^^^^^^^^^^ 3 │ ℹ Unsafe fix: Wrap the statement with a `JsBlockStatement` 1 │ - ··do; 1 │ + ··do·{} 2 2 │ while (x); 3 3 │ </code></pre>

   while (x);

<pre class="language-text"><code class="language-text">code-block.js:1:4 <a href="https://biomejs.dev/linter/rules/use-block-statements">lint/style/useBlockStatements</a> FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Block statements are preferred in this position. > 1 │ while (x); │ ^^^^^^^^^^ 2 │ ℹ Unsafe fix: Wrap the statement with a `JsBlockStatement` 1 │ - ···while·(x); 1 │ + ···while·(x)·{} 2 2 │ </code></pre>

</TabItem> </Tabs>

How to configure

Description

Examples

Invalid

Related links