fix(storage): honor byteOffset/byteLength in native and server toBase64

Author: osama-rizk

packages/storage/__tests__/client/utils/toBase64.native.test.ts

@@ -21,6 +21,12 @@ describe('client/utils/toBase64.native (React Native)', () => {
 		expect(toBase64(bytes)).toBe('aGVsbG8=');
 	});
 
+	it('encodes a Uint8Array view over an offset into an ArrayBuffer', () => {
+		const { buffer } = new Uint8Array([0, 0, 104, 101, 108, 108, 111, 0]);
+		const view = new Uint8Array(buffer, 2, 5); // "hello"
+		expect(toBase64(view)).toBe('aGVsbG8=');
+	});
+
 	it('encodes an empty ArrayBufferView', () => {
 		expect(toBase64(new Uint8Array())).toBe('');
 	});

packages/storage/__tests__/server/utils/toBase64.test.ts

@@ -21,6 +21,12 @@ describe('server/utils/toBase64', () => {
 		expect(toBase64(bytes)).toBe('aGVsbG8=');
 	});
 
+	it('encodes a Uint8Array view over an offset into an ArrayBuffer', () => {
+		const { buffer } = new Uint8Array([0, 0, 104, 101, 108, 108, 111, 0]);
+		const view = new Uint8Array(buffer, 2, 5); // "hello"
+		expect(toBase64(view)).toBe('aGVsbG8=');
+	});
+
 	it('encodes an empty ArrayBufferView', () => {
 		expect(toBase64(new Uint8Array())).toBe('');
 	});

packages/storage/src/client/utils/toBase64.native.ts

@@ -14,5 +14,7 @@ export const toBase64: ToBase64 = input => {
 		return Buffer.from(input, 'utf-8').toString('base64');
 	}
 
-	return Buffer.from(input.buffer).toString('base64');
+	return Buffer.from(input.buffer, input.byteOffset, input.byteLength).toString(
+		'base64',
+	);
 };

packages/storage/src/server/utils/toBase64.ts

@@ -15,5 +15,7 @@ export const toBase64: ToBase64 = input => {
 		return Buffer.from(input, 'utf-8').toString('base64');
 	}
 
-	return Buffer.from(input.buffer).toString('base64');
+	return Buffer.from(input.buffer, input.byteOffset, input.byteLength).toString(
+		'base64',
+	);
 };