fix(caa upload): compatibility with GM3

Under GM3, the script wasn't properly switching contexts when
processing `Uint*Array` instances created from `ArrayBuffer`s.
See #224 (comment)

src/compat.ts

@@ -51,7 +51,9 @@ export function cloneIntoPageContext<T>(object: T): T {
  * running in the page context, returns the object from this context's window
  * instead.
  */
-export function getFromPageContext<M extends keyof Window>(name: M): Window[M] {
+export function getFromPageContext<M extends keyof Window>(name: M): Window[M];
+export function getFromPageContext<M extends keyof typeof globalThis>(name: M): (typeof globalThis)[M];
+export function getFromPageContext<M extends keyof (Window | typeof globalThis)>(name: M): (Window | typeof globalThis)[M] {
     if (typeof unsafeWindow !== 'undefined') {
         return unsafeWindow[name];
     } else {

src/lib/util/blob.ts

@@ -1,5 +1,8 @@
+import { getFromPageContext } from '@src/compat';
+
 function hexEncode(buffer: ArrayBuffer): string {
     // https://stackoverflow.com/a/40031979
+    const Uint8Array = getFromPageContext('Uint8Array');
     return [...new Uint8Array(buffer)]
         .map((b) => b.toString(16).padStart(2, '0'))
         .join('');

src/mb_enhanced_cover_art_uploads/fetch.ts

@@ -4,6 +4,7 @@ import { getMaximisedCandidates } from './maximise';
 import { getProvider } from './providers';
 import { ArtworkTypeIDs } from './providers/base';
 import type { CoverArt, CoverArtProvider } from './providers/base';
+import { getFromPageContext } from '@src/compat';
 
 interface ImageContents {
     requestedUrl: URL;
@@ -195,6 +196,7 @@ export class ImageFetcher {
             const reader = new FileReader();
             // istanbul ignore next: Copied from MB.
             reader.addEventListener('load', () => {
+                const Uint32Array = getFromPageContext('Uint32Array');
                 const uint32view = new Uint32Array(reader.result as ArrayBuffer);
                 if ((uint32view[0] & 0x00FFFFFF) === 0x00FFD8FF) {
                     resolve('image/jpeg');