In the upcoming lecture will be adding catch blocks to our state/action-creators/index.ts file. Similarly to issues seen throughout the course now, we will need to add some type guards.

Find the fetchCells action creator's catch block and refactor it to look like this:

... 

   } catch (err) {
      if (err instanceof Error) {
        dispatch({
          type: ActionType.FETCH_CELLS_ERROR,
          payload: err.message,
        });
      }
    }

...

Find the saveCells action creator's catch block and refactor it to look like this:

...

    } catch (err) {
      if (err instanceof Error) {
        dispatch({
          type: ActionType.SAVE_CELLS_ERROR,
          payload: err.message,
        });
      }
    }

...