fix(web): fix some casting issue on Web JS Interop

[Lyokone]

Description

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Related Issues

fixes #12820

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[kevmoo]

But this is invalid code, I think! Runtime behavior will be wrong w/ wasm!

[srujzs]

Drive-by comment:

It looks like both Dart values and JS values flow to value. In this case, I'd recommend checking all the Dart values first (is DateTime, etc.). After that, I'd cast value to a JSAny?, and then do isA checks with the resulting JSAny?. As an example:

if (value is DateTime) {
  ...
} else {
  // Note that if value is still a Dart value, this cast is unsafe, so check all the Dart values first.
  final jsValue = value as JSAny?;
  if (jsValue.isA<GeoPointJsImpl>()) {
    ...
  } else if (jsValue.isA<JSArray>()) {
    List<JSAny?> list = (jsValue as JSArray).toDart;
    ...
  }
}

It also looks like there's a check against List<dynamic>. If value here is actually a JS array, use isA<JSArray>, as is List<dynamic> may be true when compiling to JS, but false when compiling to Wasm. The general guidance is that if a value is a JS value, use interop to type-check it and not Dart is checks.