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
function example(param: string | undefined) {}
class Test { constructor(public prop: string | undefined) {} }
interface Example { prop: string | undefined; }
Examples of correct code for this rule
function example(param?: string) {}
class Test { constructor(public prop?: string) {} }
interface Example { prop?: string; }
🚀 Installation
Install the package using npm
:
npm install eslint-plugin-no-explicit-undefined --save-dev
Install the package using yarn
:
yarn add eslint-plugin-no-explicit-undefined --dev
Install the package using pnpm
:
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.):
{
"extends": ["custom"],
"plugins": ["no-undefined-type-declaration"],
"rules": {
"no-undefined-type-declaration/no-undefined-type": "error"
}
}
📃 License
MIT