dart2js: default toString method crashes on Firefox

[rakudrama]

This code is trying to say "Instance of 'foo'"
Not all objects have a constructor with a name, so name$ is 'undefined'.
This causes an error in $.charCodeAt.

$.objectToString = function(object) {
  var name$ = (object.constructor.name);
  if ($.charCodeAt(name$, 0) === 36) {
    name$ = $.substring$1(name$, 1);
  }
  return 'Instance of '' + $.stringToString(name$) + ''';
};

Several tests print objects and fail because of this problem.

I suggest taking the name out of the string returned by Object.prototype.toString.call(receiver)

[DartBot]

This comment was originally written by [email protected]

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cc @peter-ahe-google.

[kasperl]

This seems very much related to issue #3240.

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Set owner to @kasperl.
Removed Priority-Medium label.
Added Priority-High, Accepted labels.

[rakudrama]

I meant to suggest using Object.prototype.toString.call(receiver) only when object.constructor.name fails.

My suggestion is not a great solution, just a crash fix. The default toString should never crash.

Consider:
#import('dart:html');
main() {
  print(window);
}

The interface name is 'Window'
The Dart name of the native class is '_DOMWindowImpl'. That could legitimately be anything.

The result of object.constructor.name is either undefined or 'Window' or 'DOMWindow' or ...
The result of Object.prototype.toString.call(object) is '[object global]' or '[object Window]' or '[object DOMWindow]' or ...
The result if getTypeNameOf(object) uses one of the above or something else to return 'DOMWindow' (and we will change this to 'Window' at some point now that WebKit has renamed DOMWindow to Window in the IDL)

While it is possible to provide toString implementations for all the dart:html types, that would add ~20K to every program. I'd rather explain the differences in names between browsers as 'each browser implements the library a little differently'. The implementation class names are different on Dartium too.

[kasperl]

This no longer crashes. Marking as fixed. Feel free to open another bug with suggestions on how to make the default toString even better!

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Added Fixed label.