extracting only error message in tests

error: "Expected { readonly errors: ReadonlyArray<Error>; readonly data: DataType }, actual null",

it.each(testCases)(
  '$methodName - $description',
  async ({ method }) => {
    const program = Effect.gen(function* () {
      const service = yield* Service;
      return yield* method(service);
    }).pipe(
      Effect.catchTags({
        ParseError: (error) => {
          const formattedError = ParseResult.TreeFormatter.formatErrorSync(error);
          return Effect.fail(formattedError);
        },
      })
    );

    await TestingRuntime.runPromise(program);
  }
);