FormDataLike.ts

import type {FileLike} from "./FileLike.js"

/**
 * A `string` or `File` that represents a single value from a set of `FormData` key-value pairs.
 */
export type FormDataEntryValue = string | FileLike

/**
 * This interface reflects minimal shape of the FormData
 */
export interface FormDataLike {
  /**
   * Appends a new value onto an existing key inside a FormData object,
   * or adds the key if it does not already exist.
   *
   * The difference between `set()` and `append()` is that if the specified key already exists, `set()` will overwrite all existing values with the new one, whereas `append()` will append the new value onto the end of the existing set of values.
   *
   * @param name The name of the field whose data is contained in `value`.
   * @param value The field's value. This can be [`Blob`](https://developer.mozilla.org/en-US/docs/Web/API/Blob)
    or [`File`](https://developer.mozilla.org/en-US/docs/Web/API/File). If none of these are specified the value is converted to a string.
   * @param fileName The filename reported to the server, when a Blob or File is passed as the second parameter. The default filename for Blob objects is "blob". The default filename for File objects is the file's filename.
   */
  append(name: string, value: unknown, fileName?: string): void

  /**
   * Returns all the values associated with a given key from within a `FormData` object.
   *
   * @param {string} name A name of the value you want to retrieve.
   *
   * @returns An array of `FormDataEntryValue` whose key matches the value passed in the `name` parameter. If the key doesn't exist, the method returns an empty list.
   */
  getAll(name: string): FormDataEntryValue[]

  /**
   * Returns an [`iterator`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols) allowing to go through the `FormData` key/value pairs.
   * The key of each pair is a string; the value is a [`FormDataValue`](https://developer.mozilla.org/en-US/docs/Web/API/FormDataEntryValue).
   */
  entries(): IterableIterator<[string, FormDataEntryValue]>

  /**
   * An alias for FormDataLike#entries()
   */
  [Symbol.iterator](): IterableIterator<[string, FormDataEntryValue]>

  readonly [Symbol.toStringTag]?: string
}