dart - DartPad allows string iteration -

i'd know why code below prints each letter of test on dartpad, , throws exception on terminal. mean, strings in dart not iterable, don't understand how works on dartpad; i'd expect exception there well. ideias?

void main() {   var test = 'test';   (var t in test) {     print(t);   } } 

i tested dart 1.14.0, happening in previous versions well.

i guess because dart converted javascript , javascript supports iterating on strings , performance reasons there no additional checks prevent it.

what imho bug, analyzer doesn't show warning, when test explicitely typed string

void main() {   string test = 'test';   (var t in test) {     print(t);   } } 

when enable strong-mode, warning though.

my_project/.analysis_options

analyzer:   strong-mode: true 

type check failed: test (string) not of type iterable

for both

var test = 'test'; // or  string test = 'test';