Fix typing around shared array buffers

Author: eqrion

src/utils/gz.ts

@@ -3,8 +3,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 async function readableStreamToBuffer(
-  stream: ReadableStream<Uint8Array>
-): Promise<Uint8Array> {
+  stream: ReadableStream<Uint8Array<ArrayBuffer>>
+): Promise<Uint8Array<ArrayBuffer>> {
   const reader = stream.getReader();
   const chunks: Uint8Array[] = [];
 
@@ -32,9 +32,21 @@ async function readableStreamToBuffer(
   return result;
 }
 
+// The Streams API doesn't support SAB, and so we need to copy from these to
+// use these API's.
+function copyBufferIfShared(buffer: Uint8Array): Uint8Array<ArrayBuffer> {
+  // Check if the buffer is a view into a larger ArrayBuffer (shared)
+  if (buffer.buffer instanceof SharedArrayBuffer) {
+    // Create a new buffer with its own ArrayBuffer
+    return new Uint8Array(buffer);
+  }
+  // Return the original buffer if it's not shared
+  return buffer as Uint8Array<ArrayBuffer>;
+}
+
 export async function compress(
-  data: string | Uint8Array<ArrayBuffer>
-): Promise<Uint8Array> {
+  data: string | Uint8Array
+): Promise<Uint8Array<ArrayBuffer>> {
   // Encode the data if it's a string
   const arrayData =
     typeof data === 'string' ? new TextEncoder().encode(data) : data;
@@ -44,22 +56,22 @@ export async function compress(
 
   // Write the data to the compression stream
   const writer = compressionStream.writable.getWriter();
-  writer.write(arrayData);
+  writer.write(copyBufferIfShared(arrayData));
   writer.close();
 
   // Read the compressed data back into a buffer
   return readableStreamToBuffer(compressionStream.readable);
 }
 
 export async function decompress(
-  data: Uint8Array<ArrayBuffer>
-): Promise<Uint8Array> {
+  data: Uint8Array
+): Promise<Uint8Array<ArrayBuffer>> {
   // Create a gzip compression stream
   const decompressionStream = new DecompressionStream('gzip');
 
   // Write the data to the compression stream
   const writer = decompressionStream.writable.getWriter();
-  writer.write(data);
+  writer.write(copyBufferIfShared(data));
   writer.close();
 
   // Read the compressed data back into a buffer