Ensure binary data is a DataView

CHANGELOG.md

@@ -7,7 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [UNRELEASED]
 
-
+* Fixed a bug with receiving binary data on the frontend, which gets [quak](https://github.com/manzt/quak) and [mosaic-widget](https://idl.uw.edu/mosaic/jupyter/) working with `@render_widget`. (#152)
 
 ## [0.3.2] - 2024-04-16
 

js/src/comm.ts

@@ -32,6 +32,7 @@ export class ShinyComm {
     const msg = {
       content: {comm_id: this.comm_id, data: data},
       metadata: metadata,
+      // TODO: need to _encode_ any buffers into base64 (JSON.stringify just drops them)
       buffers: buffers || [],
       // this doesn't seem relevant to the widget?
       header: {}

js/src/utils.ts

@@ -5,7 +5,7 @@ import { decode } from 'base64-arraybuffer';
 // along to the comm logic
 function jsonParse(x: string) {
   const msg = JSON.parse(x);
-  msg.buffers = msg.buffers.map((b: any) => decode(b));
+  msg.buffers = msg.buffers.map((base64: string) => new DataView(decode(base64)));
   return msg;
 }