fix: do not try to slice in chunk larger than the File itself

__tests__/utils/upload.spec.ts

@@ -35,9 +35,19 @@ describe('Get chunk from file', () => {
 		expect(chunk.size).toBe(10 * 1024 * 1024)
 	})
 
-	test('Chunking an invalid file', async () => {
+	test('Requesting a chunk bigger than the file', async () => {
 		const blob = new Blob([new ArrayBuffer(5 * 1024 * 1024)])
-		const file = new File([blob as BlobPart], 'image.jpg')
+		const file = new File([blob as BlobPart], 'image.jpg', { type: 'image/jpeg' })
+
+		const chunk = await getChunk(file, 0, 10 * 1024 * 1024)
+		expect(chunk.size).toBe(5 * 1024 * 1024)
+		expect(chunk.type).toBe('image/jpeg')
+
+	})
+
+	test('Chunking an unknown file', async () => {
+		const blob = new Blob([new ArrayBuffer(5 * 1024 * 1024)])
+		const file = new File([blob as BlobPart], 'image.jpg', { })
 
 		const chunk = await getChunk(file, 0, 10 * 1024 * 1024)
 		expect(chunk.size).toBe(5 * 1024 * 1024)

lib/utils/upload.ts

@@ -62,6 +62,10 @@ export const uploadData = async function(
  * garbage collection
  */
 export const getChunk = function(file: File, start: number, length: number): Promise<Blob> {
+	if (start === 0 && file.size <= length) {
+		return Promise.resolve(new Blob([file], { type: file.type || 'application/octet-stream' }))
+	}
+
 	// Since we use a global FileReader, we need to only read one chunk at a time
 	return readerLimit(() => new Promise((resolve, reject) => {
 		reader.onload = () => {

package.json

@@ -35,7 +35,7 @@
     "cypress": "cypress run --component",
     "cypress:gui": "cypress open --component",
     "test": "vitest run",
-    "test:watch": "vitest run --watch",
+    "test:watch": "vitest watch",
     "test:coverage": "vitest run --coverage",
     "l10n:extract": "node build/extract-l10n.js"
   },