noEnum

import { Tabs, TabItem } from '@astrojs/starlight/components';

<Tabs> <TabItem label="TypeScript and TSX" icon="seti:typescript"> ## Summary - Rule available since: `v1.9.0` - Diagnostic Category: [`lint/style/noEnum`](/reference/diagnostics#diagnostic-category) - This rule isn't recommended, so you need to enable it. - This rule doesn't have a fix. - The default severity of this rule is [**warning**](/reference/diagnostics#warning). ## How to configure ```json title="biome.json" { "linter": { "rules": { "style": { "noEnum": "error" } } } }

## Description
Disallow TypeScript enum.

TypeScript enums are not a type-level extension to JavaScript like type annotations or definitions.
Users may wish to disable non-type-level extensions to use bundlers or compilers that only strip types.

Const enums are not covered by this rule since `noConstEnum` already handles them.
Enums within the ambient context, including declaration files, are ignores as well.

## Examples

### Invalid

```ts
enum Foo {
    BAR = 'bar',
    BAZ = 'baz',
}

<pre class="language-text"><code class="language-text">code-block.ts:1:1 <a href="https://biomejs.dev/linter/rules/no-enum">lint/style/noEnum</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ⚠ Don't use enum > 1 │ enum Foo { │ ^^^^^^^^^^ > 2 │ BAR = 'bar', > 3 │ BAZ = 'baz', > 4 │ } │ ^ 5 │ ℹ TypeScript enums are not a type-level extension to JavaScript like type annotations or definitions. Users may wish to disable non-type-level extensions to use bundlers or compilers that only strip types. ℹ Use JavaScript objects or TypeScript unions instead. </code></pre>

Valid

const Foo = {
    BAR: 'bar',
    BAZ: 'baz',
} as const

type Foo = 'bar' | 'baz'

const enum Foo {
    BAR = 'bar',
    BAZ = 'baz',
}

</TabItem> </Tabs>

Valid

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