refactored client side upload loop

app/api.js

@@ -212,32 +212,35 @@ async function upload(
     let state = await reader.read();
     let size = 0;
     while (!state.done) {
-      const buf = state.value;
       if (canceller.cancelled) {
-        throw canceller.error;
+        ws.close();
       }
-
+      if (ws.readyState !== WebSocket.OPEN) {
+        break;
+      }
+      const buf = state.value;
       ws.send(buf);
-
       onprogress(size);
       size += buf.length;
       state = await reader.read();
       while (
         ws.bufferedAmount > ECE_RECORD_SIZE * 2 &&
-        ws.readyState === WebSocket.OPEN
+        ws.readyState === WebSocket.OPEN &&
+        !canceller.cancelled
       ) {
         await delay();
       }
     }
-    const footer = new Uint8Array([0]);
-    ws.send(footer);
+    if (ws.readyState === WebSocket.OPEN) {
+      ws.send(new Uint8Array([0])); //EOF
+    }
 
     await completedResponse;
-    ws.close();
     return uploadInfo;
-  } catch (e) {
-    ws.close(4000);
-    throw e;
+  } finally {
+    if (![WebSocket.CLOSED, WebSocket.CLOSING].includes(ws.readyState)) {
+      ws.close();
+    }
   }
 }