runGqlify function
Runs the CLI with arguments and sets exitCode.
Implementation
Future<void> runGqlify(List<String> arguments) async {
// Output may be closed early (e.g. piped into `head`); that is not an
// error of the run, so don't crash with an unhandled EPIPE.
unawaited(stdout.done.catchError((Object _) {}));
unawaited(stderr.done.catchError((Object _) {}));
exitCode = await GqlifyCommandRunner().run(arguments);
}