Future<bool> every(
bool test(T element)
)

Checks whether test accepts all elements provided by this stream.

Completes the Future when the answer is known. If this stream reports an error, the Future will report that error.

Source

/**
 * Checks whether [test] accepts all elements provided by this stream.
 *
 * Completes the [Future] when the answer is known.
 * If this stream reports an error, the [Future] will report that error.
 */
Future<bool> every(bool test(T element)) {
  _Future<bool> future = new _Future<bool>();
  StreamSubscription subscription;
  subscription = this.listen(
      (T element) {
        _runUserCode(
          () => test(element),
          (bool isMatch) {
            if (!isMatch) {
              _cancelAndValue(subscription, future, false);
            }
          },
          _cancelAndErrorClosure(subscription, future)
        );
      },
      onError: future._completeError,
      onDone: () {
        future._complete(true);
      },
      cancelOnError: true);
  return future;
}