Stdout not printing until after reading stdin when using terminal #2164
Description
I've noticed that stdout output and stdin input don't seem to be happening in the correct order if I set "console": "terminal" in my launch config. I'm guessing that maybe Dart-Code is caching the stdout output for some reason.
import 'dart:convert';
import 'dart:io';
import 'package:io/io.dart';
final Stream<String> stdinUtf8 = sharedStdIn.transform(utf8.decoder).asBroadcastStream();
final Stream<String> stdinLined = stdinUtf8.transform(LineSplitter());
Future<T> prompt<T>(String question, {T fallback, T def, String hint, T Function(String) parse}) async {
assert(T is String || parse != null, '`parse` can only be null if T is String. T is $T');
stdout.write('$question${hint != null || def != null ? ' (${hint ?? def})' : ''} >>> ');
final ret = await stdinLined.first;
print('[OUTPUT = $ret]'); // for debugging
if (ret.isEmpty && fallback != null) return def;
else if (parse != null) {
try {
return parse(ret);
} on FormatException {
return fallback;
}
}
return ret as T;
}Example:
Future<void> main() async {
final name = await prompt<String>('What is your name?');
}Expected Output (works in non-debug terminal):
$ dart bin/main.dart
What is your name? >>> <some user input>
[OUTPUT = <some user input>]Actual Output:
$ dart bin/main.dart
<some user input>
What is your name? >>> [OUTPUT = <some user input>]