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title: noAsyncPromiseExecutor
description: Learn more about noAsyncPromiseExecutor
---
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/suspicious/noAsyncPromiseExecutor`](/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-async-promise-executor`](https://eslint.org/docs/latest/rules/no-async-promise-executor)

## How to configure
```json title="biome.json"
{
	"linter": {
		"rules": {
			"suspicious": {
				"noAsyncPromiseExecutor": "error"
			}
		}
	}
}

```
## Description
Disallows using an async function as a Promise executor.

The executor function can also be an async function. However, this is usually a mistake, for a few reasons:

1. If an async executor function throws an error, the error will be lost and won't cause the newly-constructed `Promise` to reject. This could make it difficult to debug and handle some errors.
2. If a Promise executor function is using `await`, this is usually a sign that it is not actually necessary to use the `new Promise` constructor, or the scope of the `new Promise` constructor can be reduced.

## Examples

### Invalid

```js
new Promise(async function foo(resolve, reject) {})
```

<pre class="language-text"><code class="language-text">code-block.js:1:13 <a href="https://biomejs.dev/linter/rules/no-async-promise-executor">lint/suspicious/noAsyncPromiseExecutor</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━<br /><br />  <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">Promise executor functions should not be &#96;async&#96;.</span><br />  <br />  <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>new Promise(async function foo(resolve, reject) &#123;&#125;)<br />   <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;">^</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;">^</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;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><br />    <strong>2 │ </strong><br />  <br /></code></pre>

```js
  new Promise(async (resolve, reject) => {})
```

<pre class="language-text"><code class="language-text">code-block.js:1:15 <a href="https://biomejs.dev/linter/rules/no-async-promise-executor">lint/suspicious/noAsyncPromiseExecutor</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━<br /><br />  <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">Promise executor functions should not be &#96;async&#96;.</span><br />  <br />  <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>  new Promise(async (resolve, reject) =&gt; &#123;&#125;)<br />   <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;">^</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;">^</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><br />    <strong>2 │ </strong><br />  <br /></code></pre>

```js
  new Promise(((((async () => {})))))
```

<pre class="language-text"><code class="language-text">code-block.js:1:19 <a href="https://biomejs.dev/linter/rules/no-async-promise-executor">lint/suspicious/noAsyncPromiseExecutor</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━<br /><br />  <strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">Promise executor functions should not be &#96;async&#96;.</span><br />  <br />  <strong><span style="color: Tomato;">&gt;</span></strong> <strong>1 │ </strong>  new Promise(((((async () =&gt; &#123;&#125;)))))<br />   <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;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><br />    <strong>2 │ </strong><br />  <br /></code></pre>

### Valid

```js
  new Promise((resolve, reject) => {})
  new Promise((resolve, reject) => {}, async function unrelated() {})
  new Foo(async (resolve, reject) => {})
  new Foo((( (resolve, reject) => {} )))
```

## Related links

- [Disable a rule](/linter/#disable-a-rule)
- [Configure the code fix](/linter#configure-the-code-fix)
- [Rule options](/linter/#rule-options)
- [Source Code](https://github.com/biomejs/biome/blob/main/crates/biome_js_analyze/src/lint/suspicious/no_async_promise_executor.rs)
- [Test Cases](https://github.com/biomejs/biome/blob/main/crates/biome_js_analyze/tests/specs/suspicious/noAsyncPromiseExecutor)

</TabItem>
</Tabs>