接口 Blob

A file-like object of immutable, raw data. Blobs represent data that isn't necessarily in a JavaScript-native format. The File interface is based on Blob, inheriting blob functionality and expanding it to support files on the user's system.

interface Blob {
    size: number;
    type: string;
    arrayBuffer(): Promise<ArrayBuffer>;
    slice(start?: number, end?: number, contentType?: string): Blob;
    stream(): ReadableStream<Uint8Array>;
    text(): Promise<string>;
}