Async custom dispatcher failures bypass retry handling

[danishsshaikh]

Problem

The SDK supports custom telemetry dispatchers through the dispatcher config option:

dispatcher?: { dispatch: (event: any) => void };

However, custom dispatchers may perform async work such as calling fetch, writing to IndexedDB, or pushing telemetry to a queue.

Currently, TelemetrySyncManager calls the custom dispatcher without await in both the normal sync path and the retry path:

this._config.dispatcher.dispatch(telemetryObj);

If the custom dispatcher returns a rejected Promise, the surrounding try/catch will not catch the failure. This can cause the SDK to treat the dispatch as successful and skip the existing failed-batch retry handling.

Expected behavior

Async custom dispatcher failures should be handled the same way as failures from the default dispatcher:

• rejected async dispatches should be caught,
• failed batches should be added to the failed batch queue,
• retry logic should be triggered.

Suggested fix

• Update the custom dispatcher type to allow void | Promise<unknown>.
• Await custom dispatcher calls in both normal sync and retry sync paths.
• Add a regression test for rejected async custom dispatchers.