noImportAssign

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/noImportAssign`](/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-import-assign`](https://eslint.org/docs/latest/rules/no-import-assign)

How to configure

json

{
	"linter": {
		"rules": {
			"suspicious": {
				"noImportAssign": "error"
			}
		}
	}
}

Description

Disallow assigning to imported bindings

Examples

Invalid

import x from "y";
x = 1;

<pre class="language-text"><code class="language-text">code-block.js:2:1 <a href="https://biomejs.dev/linter/rules/no-import-assign">lint/suspicious/noImportAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ The imported variable x is read-only 1 │ import x from "y"; > 2 │ x = 1; │ ^ 3 │ ℹ The variable is imported here > 1 │ import x from "y"; │ ^ 2 │ x = 1; 3 │ ℹ Use a local variable instead of reassigning an import. </code></pre>

import y from "y";
[y] = 1;

<pre class="language-text"><code class="language-text">code-block.js:2:2 <a href="https://biomejs.dev/linter/rules/no-import-assign">lint/suspicious/noImportAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ The imported variable y is read-only 1 │ import y from "y"; > 2 │ [y] = 1; │ ^ 3 │ ℹ The variable is imported here > 1 │ import y from "y"; │ ^ 2 │ [y] = 1; 3 │ ℹ Use a local variable instead of reassigning an import. </code></pre>

import z from "y";
({ z } = 1);

<pre class="language-text"><code class="language-text">code-block.js:2:4 <a href="https://biomejs.dev/linter/rules/no-import-assign">lint/suspicious/noImportAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ The imported variable z is read-only 1 │ import z from "y"; > 2 │ ({ z } = 1); │ ^ 3 │ ℹ The variable is imported here > 1 │ import z from "y"; │ ^ 2 │ ({ z } = 1); 3 │ ℹ Use a local variable instead of reassigning an import. </code></pre>

import a from "y";
[...a] = 1;

<pre class="language-text"><code class="language-text">code-block.js:2:5 <a href="https://biomejs.dev/linter/rules/no-import-assign">lint/suspicious/noImportAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ The imported variable a is read-only 1 │ import a from "y"; > 2 │ [...a] = 1; │ ^ 3 │ ℹ The variable is imported here > 1 │ import a from "y"; │ ^ 2 │ [...a] = 1; 3 │ ℹ Use a local variable instead of reassigning an import. </code></pre>

import b from "y";
({ ...b } = 1);

<pre class="language-text"><code class="language-text">code-block.js:2:7 <a href="https://biomejs.dev/linter/rules/no-import-assign">lint/suspicious/noImportAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ The imported variable b is read-only 1 │ import b from "y"; > 2 │ ({ ...b } = 1); │ ^ 3 │ ℹ The variable is imported here > 1 │ import b from "y"; │ ^ 2 │ ({ ...b } = 1); 3 │ ℹ Use a local variable instead of reassigning an import. </code></pre>

import c from "y";
for (c in y) {};

<pre class="language-text"><code class="language-text">code-block.js:2:6 <a href="https://biomejs.dev/linter/rules/no-import-assign">lint/suspicious/noImportAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ The imported variable c is read-only 1 │ import c from "y"; > 2 │ for (c in y) {}; │ ^ 3 │ ℹ The variable is imported here > 1 │ import c from "y"; │ ^ 2 │ for (c in y) {}; 3 │ ℹ Use a local variable instead of reassigning an import. </code></pre>

import d from "y";
d += 1;

<pre class="language-text"><code class="language-text">code-block.js:2:1 <a href="https://biomejs.dev/linter/rules/no-import-assign">lint/suspicious/noImportAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ The imported variable d is read-only 1 │ import d from "y"; > 2 │ d += 1; │ ^ 3 │ ℹ The variable is imported here > 1 │ import d from "y"; │ ^ 2 │ d += 1; 3 │ ℹ Use a local variable instead of reassigning an import. </code></pre>

import * as e from "y";
e = 1;

<pre class="language-text"><code class="language-text">code-block.js:2:1 <a href="https://biomejs.dev/linter/rules/no-import-assign">lint/suspicious/noImportAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ The imported variable e is read-only 1 │ import * as e from "y"; > 2 │ e = 1; │ ^ 3 │ ℹ The variable is imported here > 1 │ import * as e from "y"; │ ^ 2 │ e = 1; 3 │ ℹ Use a local variable instead of reassigning an import. </code></pre>

</TabItem> </Tabs>

How to configure

Description

Examples

Invalid

Related links