guardz/dist/typeguards/isDefined.d.ts

A simple and lightweight TypeScript type guard library for runtime type validation.

import type { TypeGuardFn } from './isType';
/**
 * Checks if a value is not null and not undefined (is defined).
 *
 * This is the opposite of isNil - it returns true for any value that is not null or undefined.
 *
 * @param value - The value to check
 * @param config - Optional configuration for error handling
 * @returns True if the value is not null and not undefined, false otherwise
 *
 * @example
 * ```typescript
 * import { isDefined } from 'guardz';
 *
 * console.log(isDefined("hello")); // true
 * console.log(isDefined(0)); // true
 * console.log(isDefined(false)); // true
 * console.log(isDefined("")); // true
 * console.log(isDefined({})); // true
 * console.log(isDefined([])); // true
 * console.log(isDefined(null)); // false
 * console.log(isDefined(undefined)); // false
 *
 * // Useful for filtering out null/undefined values
 * const data: unknown = getUserInput();
 * if (isDefined(data)) {
 *   // data is now typed as NonNullable<unknown>
 *   // TypeScript knows data is not null or undefined
 * }
 * ```
 */
export declare const isDefined: TypeGuardFn<NonNullable<unknown>>;