Implement dput checks robustly

[vsmenon]

From @vsmenon on May 8, 2015 16:58

dput needs to check:

• NSM for non-existent fields (for JS types too?)
• Writability (final fields, methods, no setter)
• Type check - value passed in must be a subtype of field / setter type

dload needs to check:

• NSM for non-existent fields (for JS types too?)

Copied from original issue: dart-archive/dev_compiler#170

[jacob314]

Updated checkboxes

[jmesserly]

Just tested, all of the writability checks work except final fields. We are checking the type though, which is interesting.

$ cat test.dart

class C {
  final x = "hello";
  get y => ", ";
  m() => "world!";
}

main() {
  dynamic c = new C();
  print(c.x + c.y + c.m());

  try { c.x = 1; } catch(e) { print('c.x= throws $e'); }
  try { c.x = '1'; } catch(e) { print('c.x= throws $e'); }
  try { c.y = '2'; } catch(e) { print('c.y= throws $e'); }
  try { c.m = '3'; } catch(e) { print('c.m= throws $e'); }
  print(c.x);
  print(c.y);
  print(c.m);
}

$ ddc test.dart 

hello, world!
c.x= throws Type 'int' is not a subtype of type 'String'
c.y= throws NoSuchMethodError : method not found: 'Symbol("y")'
Receiver: Instance of 'C'
Arguments: ["2"]
c.m= throws NoSuchMethodError : method not found: 'Symbol("m")'
Receiver: Instance of 'C'
Arguments: ["3"]
1
, 
Closure: () -> dynamic from: function () { [native code] }

edit: the symbols for setters in nSM is wrong, I've filed that over here: #29486

[jmesserly]

https://codereview.chromium.org/2847893002/