Exercise: Listening to events

hint.txt

Did you remember to call listen() on the stream?

Did you call to processValue inside listen()?

main.dart

import 'dart:async';

void listenToStream(Stream<String> stream) {
  // implement this method
}

solution.dart

void listenToStream(Stream<String> stream) {
  stream.listen((event) => processValue(event));
}

test.dart

var processWasCalled = false;

void processValue(String value) {
  print(value);
  processWasCalled = value == "event";
}

void main() {
  // ignore: close_sinks
  final controller = StreamController<String>(sync: true);
  final stream = controller.stream;

  listenToStream(stream);

  // Check if student used `listen`
  if (!controller.hasListener) {
    _result(false, ['Something went wrong! Stream has no listeners. Did you call to `stream.listen()`?']);
    return;
  }

  controller.add("event");

  // Check if student called to processValue inside listen
  if (processWasCalled) {
    _result(true);
  } else {
    _result(false, ['Something whent wrong! `processValue()` was not called when emitting a value']);
  }
}