Dart - processing stream of JSON documents

main.dart

import 'dart:convert';

main() async {
  const jsons = '{"foo": "Ø"}\n{"bar": false}';
  final bytes = utf8.encode(jsons);

  // partitions breaking the bytes between invalid UTF-8 boundaries
  final partitions =
      Stream.fromIterable([bytes.sublist(0, 10), bytes.sublist(10)]);

  // naive approach doesn't work
  // (Unfinished UTF-8 octet sequence (at offset 10))

  // await for (final partition in partitions) {
  //   final json = utf8.decode(partition);
  //   print(jsonDecode(json));
  // }

  // correct approach using chunked conversion
  final decodedJsons = partitions
      .transform(const Utf8Decoder())
      .transform(const LineSplitter())
      .map((json) => jsonDecode(json));

  await for (final json in decodedJsons) {
    print(json);
  }
}