FormData type missing File type in get(), getAll() and forEach()

[gffuma]

The FormData type bundled in workers types miss File type in get(), getAll() and forEach() methods and only use string.

Bundled type:

declare class FormData {
  constructor();
  /* [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/append) */
  append(name: string, value: string): void;
  /* [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/append) */
  append(name: string, value: Blob, filename?: string): void;
  /* [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/delete) */
  delete(name: string): void;
  /* [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/get) */
  get(name: string): string | null;
  /* [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/getAll) */
  getAll(name: string): string[];
  /* [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/has) */
  has(name: string): boolean;
  /* [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/set) */
  set(name: string, value: string): void;
  /* [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/set) */
  set(name: string, value: Blob, filename?: string): void;
  /* Returns an array of key, value pairs for every entry in the list. */
  entries(): IterableIterator<[key: string, value: string]>;
  /* Returns a list of keys in the list. */
  keys(): IterableIterator<string>;
  /* Returns a list of values in the list. */
  values(): IterableIterator<File | string>;
  forEach<This = unknown>(
    callback: (
      this: This,
      value: string,
      key: string,
      parent: FormData,
    ) => void,
    thisArg?: This,
  ): void;
  [Symbol.iterator](): IterableIterator<[key: string, value: string]>;
}

DOM type:

interface FormData {
    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/append) */
    append(name: string, value: string | Blob): void;
    append(name: string, value: string): void;
    append(name: string, blobValue: Blob, filename?: string): void;
    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/delete) */
    delete(name: string): void;
    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/get) */
    get(name: string): FormDataEntryValue | null;
    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/getAll) */
    getAll(name: string): FormDataEntryValue[];
    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/has) */
    has(name: string): boolean;
    /** [MDN Reference](https://developer.mozilla.org/docs/Web/API/FormData/set) */
    set(name: string, value: string | Blob): void;
    set(name: string, value: string): void;
    set(name: string, blobValue: Blob, filename?: string): void;
    forEach(callbackfn: (value: FormDataEntryValue, key: string, parent: FormData) => void, thisArg?: any): void;
}

Where FormDataEntryValue is:

type FormDataEntryValue = File | string;

[emily-shen]

What version of workers-types are you using? Seems to include File on 4.20241106

[Cherry]

Also note that File support with FormData was only added by the formdata_parser_supports_files compat flag, which became default on 2021-11-03. You will need to make sure you're using @cloudflare/workers-types/2021-11-03 or newer as the default won't include it.

Compare the default:
https://github.com/Cloudflare-Mining/Cloudflare-Datamining/blob/1e63356b12a575e1b061d8ec03abdc160cb77b69/data/workers-types/2021-11-03/index.ts#L1354 - get(name: string): string | null;

vs a newer version: https://github.com/Cloudflare-Mining/Cloudflare-Datamining/blob/main/data/workers-types/2021-11-03/index.ts#L1354 - get(name: string): (File | string) | null;

Make sure you're using @cloudflare/workers-types/2021-11-03 or newer in your tsconfig.json, as per the instructions in the README: https://www.npmjs.com/package/@cloudflare/workers-types