Shortcircuit sync loop if we've requested to stop syncing (#323)

* Shortcircuit sync loop if we've requested to stop syncing

* Update src/MatrixClient.ts

Co-authored-by: Andrew Ferrazzutti <andrewf@element.io>

* Apply suggestions from code review

---------

Co-authored-by: Andrew Ferrazzutti <andrewf@element.io>
Co-authored-by: Travis Ralston <travpc@gmail.com>

src/MatrixClient.ts

@@ -721,6 +721,12 @@ export class MatrixClient extends EventEmitter {
  await Promise.resolve(this.storage.setSyncToken(token));
  }
  } catch (e) {
+ // If we've requested to stop syncing, don't bother checking the error.
+ if (this.stopSyncing) {
+ LogService.info("MatrixClientLite", "Client stop requested - cancelling sync");
+ return;
+ }
+
  LogService.error("MatrixClientLite", "Error handling sync " + extractRequestError(e));
  const backoffTime = SYNC_BACKOFF_MIN_MS + Math.random() * (SYNC_BACKOFF_MAX_MS - SYNC_BACKOFF_MIN_MS);
  LogService.info("MatrixClientLite", `Backing off for ${backoffTime}ms`);