Handling errors in the Effect library can be a bit tricky at first, especially when dealing with ...

const DatabaseServiceMock = Layer.effect(
  DatabaseService,
  Effect.sync(() => {
    return {
      upsert: () =>
        pipe(
          Effect.promise(async () => {
            return Effect.fail(
              new DatabaseUpsertError('bad thing happened')
            );
          }),
          Effect.flatten,
        ),
      query: () =>
        Effect.promise(async () => {
          return {
            data: [],
            error: 'bad thing happened',
          } as PostgrestSingleResponse<any>;
        }),
    };
  }),
);

  const result = yield* pipe(
    Effect.match(
      Effect.promise(async () =>
        database.upsert('TableName', upsertList),
      ),
      {
        onFailure: (error) => {
          console.log('ERROR', error);
          return { error: 1 };
        },
        onSuccess: (res) => {
          console.log('SUCCESS', res);
          return res;
        },
      },
    ),
    Effect.flatten,
  );