Dart 1.23 (strong mode) can not infer the type well

[tomyeh]

With the following code:

const dur = const Duration(seconds: 10);
final val = dur.inSeconds;

Dart 1.23 (dartanalyzer) said "hint • The type of 'val' can't be inferred because of the use of the instance getter 'inSeconds'"

Note: there is no such issue in Dart 1.22.1

[mit-mit]

@floitschG language or analyzer issue?

[bwilkerson]

I believe that analyzer is implementing the specification correctly.

[mit-mit]

But the implementation changed in 1.23 (the original bug text says it worked in 1.22.1)?

[leafpetersen]

Strong mode top level inference restrictions (#28218) were incrementally rolled out in 1.23 (note that we issue a hint not an error). These will become errors in 1.24.

[tomyeh]

Sorry, I don't get it. Does it mean I have to specify the type explicitly even though it can be inferred from the expression? And, this restriction is only applied to top-level variables, while local variables has no such limitation?

[leafpetersen]

We've rolled back the proposed restrictions to top level inference. This should work again.