axios/lib/core/createMultipartBody.js

Promise based HTTP client for the browser and node.js

import utils from '../utils.js';
import platform from '../platform/index.js';
import AxiosError from './AxiosError.js';
import formDataToBlob, { FormDataError } from '../helpers/formDataToBlob.js';

export default function createMultipartBody(form, Blob, limit, limitError, boundary) {
  // Report missing Blob support before trying to select a random source.
  if (!utils.isFunction(Blob)) {
    throw new AxiosError('Blob is not supported', AxiosError.ERR_NOT_SUPPORT);
  }

  if (boundary === undefined) {
    if (utils.isFunction(platform.generateString)) {
      boundary = 'axios-' + platform.generateString(36, '0123456789abcdef');
    } else {
      const crypto = utils.global.crypto;
      if (!crypto || !utils.isFunction(crypto.getRandomValues)) {
        throw new AxiosError('Random byte generation is not supported', AxiosError.ERR_NOT_SUPPORT);
      }
      const random = new Uint8Array(18);
      crypto.getRandomValues(random);
      boundary =
        'axios-' + Array.from(random, (value) => ('0' + value.toString(16)).slice(-2)).join('');
    }
  }

  try {
    return formDataToBlob(form, Blob, limit, limitError, boundary);
  } catch (error) {
    if (error instanceof FormDataError) {
      const code =
        error.reason === 'boundary' ? AxiosError.ERR_BAD_OPTION_VALUE : AxiosError.ERR_BAD_REQUEST;
      throw new AxiosError(error.message, code);
    }
    throw error;
  }
}