guardz/dist/typeguards/isFile.d.ts

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

import type { TypeGuardFn } from './isType';
/**
 * Checks if a value is a File object.
 *
 * This type guard is primarily useful in browser environments where File objects
 * are available. In Node.js environments, this will always return false.
 *
 * @param value - The value to check
 * @param config - Optional configuration for error handling
 * @returns True if the value is a File object, false otherwise
 *
 * @example
 * ```typescript
 * import { isFile } from 'guardz';
 *
 * // Browser environment
 * const fileInput = document.querySelector('input[type="file"]');
 * if (fileInput?.files?.[0] && isFile(fileInput.files[0])) {
 *   // file is typed as File
 *   console.log('File name:', file.name);
 *   console.log('File size:', file.size);
 * }
 *
 * // With error handling
 * const data: unknown = getFileData();
 * if (!isFile(data, { identifier: 'uploadedFile' })) {
 *   console.error('Invalid file data');
 *   return;
 * }
 * // data is now typed as File
 * ```
 */
export declare const isFile: TypeGuardFn<File>;