Issue by jmesserlyOriginally opened as dart-lang/sdk#16123
If the model is a String, and the path is something invalid like "foo.bar", _getObjectProperty will try to index into it with "foo", which fails.
Either we need to be generally more restrictive about invalid paths (there is precedent, AFAIK Angular.dart is heading in that direction. Perhaps only nullable should be checked for.), or this bit of code needs to check for something else, perhaps a type test on Map<String, dynamic>
DartBot
commented
9 years ago 
If the model is a String, and the path is something invalid like "foo.bar", _getObjectProperty will try to index into it with "foo", which fails.
Either we need to be generally more restrictive about invalid paths (there is precedent, AFAIK Angular.dart is heading in that direction. Perhaps only nullable should be checked for.), or this bit of code needs to check for something else, perhaps a type test on Map<String, dynamic>