<input type="number" ng-model="ctrl.foo"> rapidly alternates between int and String

[trinarytree]

controller...

String _foo = '1';
String get foo => _foo;
void set foo(String value) {
  _foo = value;
  print('type ${_foo.runtimeType}');
}

template...

<input type="number" ng-model="ctrl.foo">

now try clicking on the buttons that increment or decrement the number.
on the debugging console, you'll see the runtimeType of foo rapidly alternating
between String and int. that's pretty annoying because now you can't declare it
as either. you have to make it dynamic or Object and write all code to handle either.

[trinarytree]

i should mention that the problem has nothing to do with the declared types of the foo getter and setter. e.g.

int _foo = 1;
int get foo => _foo;
void set foo(int value) {
  _foo = value;
  print('type ${_foo.runtimeType}');
}

yields exactly the same problem.

[trinarytree]

here is a fiddle to explore what normal html/js does with <input type="number">.
http://jsfiddle.net/GQ3U3/
when the input is valid, it yields a string that parses as an integer.
when the input is invalid, the value is the empty string.

by contrast, in angular.dart, apart from alternating type bug mentioned above,
invalid input yields NaN, which in dart is a double. that yields confusing type errors.
could the behavior please be changed so that
(1) valid input always yields an int (not a String or double)
(2) invalid input always yields null (not NaN or other silliness).

[chirayuk]

Yes, I see the issue.  It's a bug.