Incorrect constant evaluation of lists declared in another file

[stereotype441]

Consider the following code:

lib.dart:

const x = const <String>['a'];

main.dart:

import 'lib.dart';
const y = const <String>['b'];
int f(v) {
  switch(v) {
    case x:
      return 0;
    case y:
      return 1;
    default:
      return 2;
  }
}

If the analysis driver visits main.dart first, then it evaluates the constant x as having the value <dynamic>['a'], and the constant y as having the value <String>['b']. This is incorrect--both lists should have type argument <String>. As a result, the error INCONSISTENT_CASE_EXPRESSION_TYPES is reportend.

Note that the type that is incorrect is the type of the constant value, not the static type of the constant declaration. Replacing const x = ... with const List<String>x = ... in the code above is not sufficient to work around the bug.

It's also possible to get inconsistencies between two constants declared in the same file, if one of the constants is referred to by another file, and the analysis driver visits that other file first.

[stereotype441]

I'm working on a fix

[bwilkerson]

@keertip