some member names likely don't work right for types with "call" method

[jmesserly]

(moved from dart-archive/dev_compiler#593)

In particular, those that are inherited from JS Functions, like "name" and "length".

We also allow shadowing methods like "call" and "apply". This may cause problems in our runtime, or in JS code that gets these objects. We should probably symbolize call/apply to avoid collision.

[jmesserly]

CC @alan-knight who saw a related issue

[greglittlefield-wf]

We needed to work around this issue to use the DDC, so I implemented a runtime fix to the issue with the name accessor until the underlying issue is fixed, if anyone's interested:

• implementation
• usage
• tests

It's hacky and brittle and I'm not super proud of it, but it gets the job done if you really need to work around this issue.

[jmesserly]

CC @vsmenon @grouma -- this is the bug for some member names not working on "callable" classes

[jmesserly]

Here's a test demonstrating the issues:

class Foo {
  final name = 'FOO!';
  final length = 123;
  call() => 'hello world';
  bind(int x) => x + 40;
  apply(x, y) => 'called apply($x, $y)';
}
main() {
  var f = new Foo();
  print(f());
  // Fails because Dart sets these with `this.name =` and `this.length =` and
  // that's ignored because the data properties are not writable
  // (http://www.ecma-international.org/ecma-262/6.0/#sec-function.length)
  print(f.name);
  print(f.length);
  // works because Dart method shadows the JS ones (probably breaks JS interop)
  print(f.apply(1, 2));
  print(f.bind(2));
  // This happens to work because DDC checks `f instanceof Function` rather than
  // `typeof f == "function"`, causing it to tearoff the `call` method rather
  // than directly calling `f.apply`.
  print((f as dynamic)());
}

One way to fix this would be to treat classes with call methods as a "native type" because they are instances of JS functions at runtime. But that's a pretty blunt instrument.

[jmesserly]

this was fixed. callable classes are not subtypes of function types any longer, so we do not represent them the same way in JS