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noSetterReturn

src/content/docs/linter/rules/no-setter-return.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/noSetterReturn`](/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-setter-return`](https://eslint.org/docs/latest/rules/no-setter-return)

How to configure

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

Description

Disallow returning a value from a setter

While returning a value from a setter does not produce an error, the returned value is being ignored. Therefore, returning a value from a setter is either unnecessary or a possible error.

Only returning without a value is allowed, as it’s a control flow statement.

Examples

Invalid

js
class A {
    set foo(x) {
        return x;
    }
}
<pre class="language-text"><code class="language-text">code-block.js:3:9 <a href="https://biomejs.dev/linter/rules/no-setter-return">lint/correctness/noSetterReturn</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">The setter should not </span><span style="color: Tomato;"><strong>return</strong></span><span style="color: Tomato;"> a value.</span> <strong>1 │ </strong>class A &#123; <strong>2 │ </strong> set foo(x) &#123; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>3 │ </strong> return x; <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><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>4 │ </strong> &#125; <strong>5 │ </strong>&#125; <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">The setter is here:</span> <strong>1 │ </strong>class A &#123; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>2 │ </strong> set foo(x) &#123; <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><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;">&gt;</span></strong> <strong>3 │ </strong> return x; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>4 │ </strong> &#125; <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong> <strong>5 │ </strong>&#125; <strong>6 │ </strong> <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Returning a value from a setter is ignored.</span> </code></pre>
js
const b = {
    set foo(x) {
        return x;
    },
};
<pre class="language-text"><code class="language-text">code-block.js:3:9 <a href="https://biomejs.dev/linter/rules/no-setter-return">lint/correctness/noSetterReturn</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">The setter should not </span><span style="color: Tomato;"><strong>return</strong></span><span style="color: Tomato;"> a value.</span> <strong>1 │ </strong>const b = &#123; <strong>2 │ </strong> set foo(x) &#123; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>3 │ </strong> return x; <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><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>4 │ </strong> &#125;, <strong>5 │ </strong>&#125;; <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">The setter is here:</span> <strong>1 │ </strong>const b = &#123; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>2 │ </strong> set foo(x) &#123; <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><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;">&gt;</span></strong> <strong>3 │ </strong> return x; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>4 │ </strong> &#125;, <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong> <strong>5 │ </strong>&#125;; <strong>6 │ </strong> <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Returning a value from a setter is ignored.</span> </code></pre>
js
const c = {
    set foo(x) {
        if (x) {
            return x;
        }
    },
};
<pre class="language-text"><code class="language-text">code-block.js:4:13 <a href="https://biomejs.dev/linter/rules/no-setter-return">lint/correctness/noSetterReturn</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">The setter should not </span><span style="color: Tomato;"><strong>return</strong></span><span style="color: Tomato;"> a value.</span> <strong>2 │ </strong> set foo(x) &#123; <strong>3 │ </strong> if (x) &#123; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>4 │ </strong> return x; <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><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>5 │ </strong> &#125; <strong>6 │ </strong> &#125;, <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">The setter is here:</span> <strong>1 │ </strong>const c = &#123; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>2 │ </strong> set foo(x) &#123; <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><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;">&gt;</span></strong> <strong>3 │ </strong> if (x) &#123; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>4 │ </strong> return x; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>5 │ </strong> &#125; <strong><span style="color: Tomato;">&gt;</span></strong> <strong>6 │ </strong> &#125;, <strong> │ </strong> <strong><span style="color: Tomato;">^</span></strong> <strong>7 │ </strong>&#125;; <strong>8 │ </strong> <strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Returning a value from a setter is ignored.</span> </code></pre>

Valid

js
// early-return
class A {
    set foo(x) {
        if (x) {
            return;
        }
    }
}
js
// not a setter
class B {
  set(x) {
    return x;
  }
}
</TabItem> </Tabs>