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# method-signature-style

[Added in v0.5.0](https://github.com/web-infra-dev/rslint/releases/tag/v0.5.0)
## Configuration


```ts title=rslint.config.ts
import { defineConfig, ts } from '@rslint/core';

export default defineConfig([
  ts.configs.recommended,
  {
    rules: {
      '@typescript-eslint/method-signature-style': 'error',
    },
  },
]);
```

## Rule Details

Enforces using a particular method signature syntax in interfaces and type literals.

There are two styles for declaring method signatures in TypeScript:

- **Method shorthand**: `func(arg: string): number;`
- **Property**: `func: (arg: string) => number;`

The key difference: with `strictFunctionTypes` enabled, method parameters are checked less strictly, while function property parameters are checked more strictly. This makes function properties more type-safe.

### Options

- `"property"` (default): Enforces function property signature syntax.
- `"method"`: Enforces method shorthand signature syntax.

### `"property"` (default)

Examples of **incorrect** code:

```typescript
interface T1 {
  func(arg: string): number;
}
```

Examples of **correct** code:

```typescript
interface T1 {
  func: (arg: string) => number;
}
```

### `"method"`

Examples of **incorrect** code:

```typescript
interface T1 {
  func: (arg: string) => number;
}
```

Examples of **correct** code:

```typescript
interface T1 {
  func(arg: string): number;
}
```

## Original Documentation

- [typescript-eslint: method-signature-style](https://typescript-eslint.io/rules/method-signature-style)
- [Source code](https://github.com/typescript-eslint/typescript-eslint/blob/v8.58.2/packages/eslint-plugin/src/rules/method-signature-style.ts)