ShortCircuitOperators_A03_t12 is wrong

[athomas]

ShortCircuitOperators_A03_t12 expects failures for things that don't fail:

const String s1 = "" ?? 124;

Where "" ?? 124 is an expression of type Object which get implicitly cast to String. The cast succeeds because the expression evaluates to "".

In NNBD, the implicit cast doesn't happen, so the error occurs but just because the type of the expression is wrong.

So the test doesn't test what it claims to test and what it claims to test is not something that needs testing.

https://github.com/dart-lang/co19/blob/pre-nnbd/LanguageFeatures/Constant-update-2018/ShortCircuitOperators_A03_t12.dart#L21