Flutter web throws TypeError: Instance of 'JSArray<dynamic>': type 'List<dynamic>' is not a subtype of type 'List<Binding>' on hot restart. #1307
Description
In web/JS interop, .where().toList() chains infer List instead of preserving generic types, which fails on hot restart:
_bindings[typeLower] = _bindings[typeLower]!
.where((bind) => ...)
.toList(); // --> throws Exception
To Reproduce
- Set up a RealtimeChannel with event listeners using a method like onPostgresChanges()
- Run Flutter web
- Hot restart the app
- Observe the
TypeError: Instance of 'JSArray<dynamic>': type 'List<dynamic>' is not a subtype of type 'List<Binding>'
Expected Behavior and Root Cause
The off() method in the RealtimeChannel class should successfully remove the matching event binding from the _bindings map without any type errors.
Suggested Fix
Add explicit type casting: (this method is inside RealtimeChannel class)
@internal
RealtimeChannel off(String type, Map<String, String> filter) {
final typeLower = type.toLowerCase();
_bindings[typeLower] = _bindings[typeLower]!
.where((bind) {
return !(bind.type.toLowerCase() == typeLower &&
RealtimeChannel._isEqual(bind.filter, filter));
})
.toList()
.cast<Binding>(); // --> this cast seems to fix the issue for me !
return this;
}