line.isEmpty doesn't seem to work when copy&pasting

[vmendi]

I don't know why. I have tried to copy the text both directly from the browser console and from a text editor. Adding an empty line at the end of the buffer doesn't work.

If I copy line by line, it works. It may be something related to the end of line/carriage return character?

[bjornm]

Sounds like a potential bug in Stdin.readLineSync() - I'm on Mac and it's working fine. What os are you using? Could you please try the following dart test file and see what we get?

import 'dart:io';
import 'dart:convert';

main() {
  print("Paste something:");
  String line = "";
  do {
    String line = readLineSync();
    print("line.isEmpty=${line.isEmpty}");
  } while(line.isNotEmpty);
  print("DONE");
}

String readLineSync({Encoding encoding: SYSTEM_ENCODING,
                    bool retainNewlines: false}) {
  const CR = 13;
  const LF = 10;
  final List line = [];
  // On Windows, if lineMode is disabled, only CR is received.
  bool crIsNewline = Platform.isWindows &&
  (stdioType(stdin) == StdioType.TERMINAL) &&
  !stdin.lineMode;
  print("Platform.isWindows=${Platform.isWindows} stdioType=${stdioType(stdin)} stin.lineMode=${stdin.lineMode} crIsNewLine=$crIsNewline");
  if (retainNewlines) {
    int byte;
    do {
      byte = stdin.readByteSync();
      print("Got byte $byte");
      if (byte < 0) {
        break;
      }
      line.add(byte);
    } while (byte != LF && !(byte == CR && crIsNewline));
    if (line.isEmpty) {
      return null;
    }
  } else if (crIsNewline) {
    // CR and LF are both line terminators, neither is retained.
    while (true) {
      int byte = stdin.readByteSync();
      print("Got byte $byte");
      if (byte < 0) {
        if (line.isEmpty) return null;
        break;
      }
      if (byte == LF || byte == CR) break;
      line.add(byte);
    }
  } else {
    // Case having to hande CR LF as a single unretained line terminator.
    outer: while (true) {
      int byte = stdin.readByteSync();
      print("Got byte $byte");
      if (byte == LF) break;
      if (byte == CR) {
        do {
          byte = stdin.readByteSync();
          print("Got byte $byte");
          if (byte == LF) break outer;

          line.add(CR);
        } while (byte == CR);
        // Fall through and handle non-CR character.
      }
      if (byte < 0) {
        if (line.isEmpty) return null;
        break;
      }
      line.add(byte);
    }
  }
  return encoding.decode(line);
}