The matching state in the widget tree.
Throws a StateError if finder is empty, matches more than
one state, or matches a widget that has no state.
- Use firstState if you expect to match several states but only want the first.
- Use stateList if you expect to match several states and want all of them.
Source
State/*=T*/ state/*<T extends State>*/(Finder finder) {
TestAsyncUtils.guardSync();
return _stateOf/*<T>*/(finder.evaluate().single, finder);
}