Revert "BlobManager: implement Blob from ArrayBuffer (facebook#39276)" (

facebook#41170)

Summary:
As per facebook#41079, we're outputting ASCII encoded data URIs to `FileReader.readAsDataURL` due to lack of native `ArrayBuffer` support and unclear use of encoding to align with web. I'll revisit this at a later point with a better testing strategy once we have a good idea of how this should behave internally.

Aside from purely reverting facebook#39276, I've kept the use of `ArrayBuffer.isView(part)` to the previous `part instanceof global.ArrayBufferView` since it is more correct.

## Changelog:

[INTERNAL] [REMOVED] - Revert Blob from ArrayBuffer

Pull Request resolved: facebook#41170

Test Plan:
Run the following at the project root to selectively test changes:

`jest packages/react-native/Libraries/Blob`

Reviewed By: cipolleschi

Differential Revision: D50601036

Pulled By: dmytrorykun

fbshipit-source-id: 0ef5c960c253db255c2f8532ea1f44111093706c

packages/react-native/Libraries/Blob/Blob.js

@@ -57,10 +57,7 @@ class Blob {
  * Currently we only support creating Blobs from other Blobs.
  * Reference: https://developer.mozilla.org/en-US/docs/Web/API/Blob/Blob
  */
- constructor(
- parts: Array<$ArrayBufferView | ArrayBuffer | Blob | string> = [],
- options?: BlobOptions,
- ) {
+ constructor(parts: Array<Blob | string> = [], options?: BlobOptions) {
  const BlobManager = require('./BlobManager');
  this.data = BlobManager.createFromParts(parts, options).data;
  }

packages/react-native/Libraries/Blob/BlobManager.js

@@ -11,7 +11,6 @@
 import type {BlobCollector, BlobData, BlobOptions} from './BlobTypes';
 
 import NativeBlobModule from './NativeBlobModule';
-import {fromByteArray} from 'base64-js';
 import invariant from 'invariant';
 
 const Blob = require('./Blob');
@@ -60,20 +59,19 @@ class BlobManager {
  * Create blob from existing array of blobs.
  */
  static createFromParts(
- parts: Array<$ArrayBufferView | ArrayBuffer | Blob | string>,
+ parts: Array<Blob | string>,
  options?: BlobOptions,
  ): Blob {
  invariant(NativeBlobModule, 'NativeBlobModule is available.');
 
  const blobId = uuidv4();
  const items = parts.map(part => {
  if (part instanceof ArrayBuffer || ArrayBuffer.isView(part)) {
- return {
- // $FlowFixMe[incompatible-cast]
- data: fromByteArray(new Uint8Array((part: ArrayBuffer))),
- type: 'string',
- };
- } else if (part instanceof Blob) {
+ throw new Error(
+ "Creating blobs from 'ArrayBuffer' and 'ArrayBufferView' are not supported",
+ );
+ }
+ if (part instanceof Blob) {
  return {
  data: part.data,
  type: 'blob',

packages/react-native/Libraries/Blob/File.js

@@ -23,7 +23,7 @@ class File extends Blob {
  * Constructor for JS consumers.
  */
  constructor(
- parts: Array<$ArrayBufferView | ArrayBuffer | Blob | string>,
+ parts: Array<Blob | string>,
  name: string,
  options?: BlobOptions,
  ) {

packages/react-native/Libraries/Blob/__tests__/Blob-test.js

@@ -15,7 +15,6 @@ jest.setMock('../../BatchedBridge/NativeModules', {
 });
 
 const Blob = require('../Blob');
-const {fromByteArray} = require('base64-js');
 
 describe('Blob', function () {
  it('should create empty blob', () => {
@@ -27,7 +26,7 @@ describe('Blob', function () {
  expect(blob.type).toBe('');
  });
 
- it('should create blob from ArrayBuffer, other blobs, strings', () => {
+ it('should create blob from other blobs and strings', () => {
  const blobA = new Blob();
  const blobB = new Blob();
  const textA = 'i \u2665 dogs';
@@ -44,20 +43,14 @@ describe('Blob', function () {
  blobA.data.size = 34540;
  blobB.data.size = 65452;
 
- const buffer = new ArrayBuffer(4);
-
- const blob = new Blob([blobA, blobB, textA, textB, textC, buffer]);
+ const blob = new Blob([blobA, blobB, textA, textB, textC]);
 
  expect(blob.size).toBe(
  blobA.size +
  blobB.size +
  global.Buffer.byteLength(textA, 'UTF-8') +
  global.Buffer.byteLength(textB, 'UTF-8') +
- global.Buffer.byteLength(textC, 'UTF-8') +
- global.Buffer.byteLength(
- fromByteArray(new Uint8Array(buffer)),
- 'UTF-8',
- ),
+ global.Buffer.byteLength(textC, 'UTF-8'),
  );
  expect(blob.type).toBe('');
  });