Function isClassConstructor()

Source: IsClassConstructor.ts

Checks whether a given value is a native ES2015 class constructor.

NOTE

Some built-in Node.js classes (e.g. EventEmitter, Readable) are not native ES2015 classes and will not pass this check. However, any user-defined class that extends such a built-in (e.g. class MyEmitter extends EventEmitter {}) is a native ES2015 class and will pass. Built-in ES2015 classes such as Map and WeakMap also pass.

Import

import { isClassConstructor } from '@litert/utils-object';

Signature

function isClassConstructor(func: unknown): func is IConstructor;

Parameters

• Parameter func: unknown

  The value to test. Any value is accepted; non-function values always return false.

Return Value

true if func is a native ES2015 class constructor; false otherwise.

When true is returned, TypeScript narrows the type of func to IConstructor (new (...args: any[]) => unknown).

Examples

import { isClassConstructor } from '@litert/utils-object';

class MyClass {}
function plainFunction() {}
const arrowFn = () => {};

console.log(isClassConstructor(MyClass));       // true
console.log(isClassConstructor(Map));           // true
console.log(isClassConstructor(WeakMap));       // true
console.log(isClassConstructor(plainFunction)); // false
console.log(isClassConstructor(arrowFn));       // false
console.log(isClassConstructor(42));            // false
console.log(isClassConstructor(null));          // false