Function asUpgradeResponse

asUpgradeResponse(
response: unknown,
binding: string,
): DurableObjectUpgradeResponse
Narrows a Durable Object stub's response to one carrying a socket.

A stub answering an ordinary Response — a 404 from a DO class with no upgrade path, a 500 from one that threw, a 101 from a runtime that does not populate webSocket — fails here, naming the binding, rather than surfacing later as a TypeError on undefined.accept() with nothing to point at.
Parameters
- response: unknown
  The stub's response
- binding: string
  The Durable Object binding name, for the error message
Returns DurableObjectUpgradeResponse
The same response, narrowed
Throws
When the response carries no webSocket
Example
```
const response = await stub.fetch('https://do/connect', {
  headers: { Upgrade: 'websocket' },
});
const socket = asUpgradeResponse(response, 'REALTIME').webSocket;
socket.accept();
```
Since
0.2.0
- Defined in packages/cloudflare-plugin/src/durable-objects/do-facades.ts:213