# ESLint Plugin: eslint-plugin-no-explicit-undefined

Disallow the use of `undefined` as an explicit type in TypeScript and instead use optional operator (`?`) instead.

## 📚 Rule Examples

This rule disallows the use of undefined as an explicit type in TypeScript. Instead, developers should use optional properties or null.

Examples of **incorrect** code for this rule ❌

```ts
function example(param: string | undefined) {}
class Test { constructor(public prop: string | undefined) {} }
interface Example { prop: string | undefined; }
```

Examples of **correct** code for this rule ✅

```ts
function example(param?: string) {} 
class Test { constructor(public prop?: string) {} }
interface Example { prop?: string; }
```

## 🚀 Installation

Install the package using `npm`:

```bash
npm install eslint-plugin-no-explicit-undefined --save-dev
```

Install the package using `yarn`:

```bash
yarn add eslint-plugin-no-explicit-undefined --dev
```

Install the package using `pnpm`:

```bash
pnpm install eslint-plugin-no-explicit-undefined --save-dev
```

## 📝 Configuration

To configure the rule, add it to your ESLint configuration file (`.eslintrc.json`, `.eslintrc.js`, etc.):

```json
{
  "extends": ["custom"],
  "plugins": ["no-undefined-type-declaration"],
  "rules": {
    "no-undefined-type-declaration/no-undefined-type": "error"
  }
}
```

## 📃 License

MIT
.