isFile

Checks if the given value is a File.

This function can also serve as a type predicate in TypeScript, narrowing the type of the argument to File.

Signature

function isFile(x: unknown): x is File;

Parameters

• x (unknown): The value to test if it is a File.

Returns

(x is File): True if the value is a File, false otherwise.

Examples

const file = new File(['content'], 'example.txt', { type: 'text/plain' });
const blob = new Blob(['content'], { type: 'text/plain' });
const value = {};

console.log(isFile(file)); // true
console.log(isFile(blob)); // false
console.log(isFile(value)); // false