is-what
Version:
JS type check (TypeScript supported) functions like `isPlainObject() isArray()` etc. A simple & small integration.
24 lines (23 loc) • 1.18 kB
TypeScript
import { AnyClass } from './isType.js';
type GlobalClassName = {
[K in keyof typeof globalThis]: (typeof globalThis)[K] extends AnyClass ? K : never;
}[keyof typeof globalThis];
/**
* Checks if a value is an instance of a class or a class name. Useful when you want to check if a
* value is an instance of a class that may not be defined in the current scope. For example, if you
* want to check if a value is an `OffscreenCanvas` instance, you might not want to do the song and
* dance of using `typeof OffscreenCanvas !== 'undefined'` and then shimming `OffscreenCanvas` if
* the types aren't around.
*
* @example
* if (isInstanceOf(value, 'OffscreenCanvas')) {
* // value is an OffscreenCanvas
* }
*
* @param value The value to recursively check
* @param class_ A string or class that the value should be an instance of
*/
export declare function isInstanceOf<T extends AnyClass>(value: unknown, class_: T): value is T;
export declare function isInstanceOf<K extends GlobalClassName>(value: unknown, className: K): value is (typeof globalThis)[K];
export declare function isInstanceOf(value: unknown, className: string): value is object;
export {};