loadLibrary() return type

[scheglov]

What is the return type of deferredPrefix.loadLibrary() when NNBD?
Currently in analyzer it is Future<dynamic>.
But this does not match CFE.
@leafpetersen @lrhn Could you clarify this?

import self as self;
import "dart:async" as asy;
import "dart:core" as core;

import "dart:math" deferred as math;

static method main() → dynamic {
  asy::Future<dynamic>? v = LoadLibrary(math);
  core::print(v);
}

[scheglov]

See the test log and the CL where is causes issues.

[lrhn]

The spec is (yet) silent on the type of the future returned, and doesn't specify the static type of the loadLibrary function. We are aware of that and have a CL to fix it: dart-lang/language#568

The change will make the static signature Future<void> loadLibrary() and I guess it can actually return any kind of future other than Future<Never>), which is completed with null.

[scheglov]

Thank you.

So, lib.loadLibrary() returns a non-nullable type (Future<void>), and the null check in isolate tests is not necessary. Probably something to fix in CFE. @a-siva

[a-siva]

/cc @johnniwinther (regarding errors from CFE when lib.loadLibrary().then is used).