handle zodfetchSSE connection errors

Author: ericallam

packages/cli-v3/src/apiClient.ts

@@ -281,6 +281,13 @@ export class CliApiClient {
       },
     });
 
+    source.onConnectionError((error) => {
+      rejectPromise({
+        success: false,
+        error,
+      });
+    });
+
     source.onMessage("complete", (message) => {
       resolvePromise({
         success: true,

packages/core/src/v3/apiClient/core.ts

@@ -655,6 +655,10 @@ export class ZodFetchSSEResult<TMessageCatalog extends ZodFetchSSEMessageCatalog
     });
   }
 
+  public onConnectionError(handler: (error: Event) => void) {
+    this._eventSource.onerror = handler;
+  }
+
   public onMessage<T extends keyof TMessageCatalog>(
     type: T,
     handler: ZodFetchSSEMessageHandlers<TMessageCatalog>[T]