Add tests for `FutureOr<T>`.

tests/lib/async/future_or_non_strong_test.dart

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// In non strong-mode, `FutureOr` should just behave like dynamic.
+
+import 'dart:async';
+import 'package:expect/expect.dart';
+
+void foo(FutureOr x) {}
+FutureOr bar() => 499;
+
+void foo2(FutureOr<String> x) {}
+FutureOr<int> bar2() => 499;
+
+void foo3(String x) {}
+int bar3() => 499;
+
+typedef void FunTakes<T>(T x);
+typedef T FunReturns<T>();
+
+main() {
+  Expect.isTrue(499 is FutureOr);
+  Expect.isTrue(499 is FutureOr<String>);

[Lasse Reichstein Nielsen, 2016/12/08 18:20:28]

is! or Expect.isFalse?

[floitsch, 2016/12/08 18:41:55]

not in non-strong mode.

+  Expect.isTrue(499 is FutureOr<int>);
+
+  Expect.isTrue(new Future.value(499) is FutureOr);
+  Expect.isTrue(new Future.value(499) is FutureOr<int>);
+  Expect.isTrue(new Future.value(499) is FutureOr<String>);

[Lasse Reichstein Nielsen, 2016/12/08 18:20:28]

This is spec mode, so it's a Future<dynamic> which is a Future<String>. Maybe
document that.

[floitsch, 2016/12/08 18:41:55]

The whole test is for spec mode. This is hinted by the name of the test and by
the description on the top of the file. Should I repeat it a third time?

[Lasse Reichstein Nielsen, 2016/12/08 19:31:00]

No, that's just me being too used to think of FutureOr in strong mode. Once is
enough.

+
+  Expect.isTrue(foo is FunTakes<dynamic>);
+  Expect.isTrue(foo is FunTakes<Object>);
+  Expect.isTrue(foo is FunTakes<int>);
+  Expect.isTrue(foo is FunTakes<String>);
+  Expect.isTrue(foo is FunTakes<Future<int>>);
+  Expect.isTrue(foo is FunTakes<Future<String>>);
+  Expect.isTrue(foo is FunTakes<FutureOr<Object>>);
+  Expect.isTrue(foo is FunTakes<FutureOr<int>>);
+  Expect.isTrue(foo is FunTakes<FutureOr<String>>);
+  Expect.isTrue(foo is FunTakes<FutureOr<FutureOr<Object>>>);
+  Expect.isTrue(foo is FunTakes<FutureOr<FutureOr<int>>>);
+  Expect.isTrue(foo is FunTakes<FutureOr<FutureOr<String>>>);
+
+  Expect.isTrue(bar is FunReturns<dynamic>);
+  Expect.isTrue(bar is FunReturns<Object>);
+  Expect.isTrue(bar is FunReturns<int>);
+  Expect.isTrue(bar is FunReturns<String>);
+  Expect.isTrue(bar is FunReturns<Future<int>>);
+  Expect.isTrue(bar is FunReturns<Future<String>>);
+  Expect.isTrue(bar is FunReturns<FutureOr<Object>>);
+  Expect.isTrue(bar is FunReturns<FutureOr<int>>);
+  Expect.isTrue(bar is FunReturns<FutureOr<String>>);
+  Expect.isTrue(bar is FunReturns<FutureOr<FutureOr<Object>>>);
+  Expect.isTrue(bar is FunReturns<FutureOr<FutureOr<int>>>);
+  Expect.isTrue(bar is FunReturns<FutureOr<FutureOr<String>>>);
+

[Lasse Reichstein Nielsen, 2016/12/08 18:20:28]

You could move the declaration of foo2 down here so it's easier to see its type.

[floitsch, 2016/12/08 18:41:55]

Done.

+  Expect.isTrue(foo2 is FunTakes<dynamic>);
+  Expect.isTrue(foo2 is FunTakes<Object>);
+  Expect.isTrue(foo2 is FunTakes<int>);

[Lasse Reichstein Nielsen, 2016/12/08 18:20:28]

is!

[floitsch, 2016/12/08 18:41:55]

Not, if `FutureOr` is equivalent to dynamic (which it is).

+  Expect.isTrue(foo2 is FunTakes<String>);
+  Expect.isTrue(foo2 is FunTakes<Future<int>>);

[Lasse Reichstein Nielsen, 2016/12/08 18:20:28]

is!

More below (everyone except Future<String>, FutureOr<String> and
FutureOr<FutureOr<String>>)

[floitsch, 2016/12/08 18:41:55]

Same answer.

+  Expect.isTrue(foo2 is FunTakes<Future<String>>);
+  Expect.isTrue(foo2 is FunTakes<FutureOr<Object>>);
+  Expect.isTrue(foo2 is FunTakes<FutureOr<int>>);
+  Expect.isTrue(foo2 is FunTakes<FutureOr<String>>);
+  Expect.isTrue(foo2 is FunTakes<FutureOr<FutureOr<Object>>>);
+  Expect.isTrue(foo2 is FunTakes<FutureOr<FutureOr<int>>>);
+  Expect.isTrue(foo2 is FunTakes<FutureOr<FutureOr<String>>>);
+
+  Expect.isTrue(bar2 is FunReturns<dynamic>);
+  Expect.isTrue(bar2 is FunReturns<Object>);
+  Expect.isTrue(bar2 is FunReturns<int>);
+  Expect.isTrue(bar2 is FunReturns<String>);

[Lasse Reichstein Nielsen, 2016/12/08 18:20:28]

is!

Same for Future<String>, FutureOr<String>, and FuturOr<FutureOr<String>>.

[floitsch, 2016/12/08 18:41:55]

Same answer.

+  Expect.isTrue(bar2 is FunReturns<Future<int>>);
+  Expect.isTrue(bar2 is FunReturns<Future<String>>);
+  Expect.isTrue(bar2 is FunReturns<FutureOr<Object>>);
+  Expect.isTrue(bar2 is FunReturns<FutureOr<int>>);
+  Expect.isTrue(bar2 is FunReturns<FutureOr<String>>);
+  Expect.isTrue(bar2 is FunReturns<FutureOr<FutureOr<Object>>>);
+  Expect.isTrue(bar2 is FunReturns<FutureOr<FutureOr<int>>>);
+  Expect.isTrue(bar2 is FunReturns<FutureOr<FutureOr<String>>>);
+
+  Expect.isTrue(foo3 is FunTakes<dynamic>);
+  Expect.isTrue(foo3 is FunTakes<Object>);

[Lasse Reichstein Nielsen, 2016/12/08 18:20:28]

is!
(Just figure out the rest :)

[floitsch, 2016/12/08 18:41:55]

No. In Dart1, foo3 *is* a function that takes `Object`.

+  Expect.isFalse(foo3 is FunTakes<int>);
+  Expect.isTrue(foo3 is FunTakes<String>);
+  Expect.isFalse(foo3 is FunTakes<Future<int>>);
+  Expect.isFalse(foo3 is FunTakes<Future<String>>);
+  Expect.isTrue(foo3 is FunTakes<FutureOr<Object>>);
+  Expect.isTrue(foo3 is FunTakes<FutureOr<int>>);
+  Expect.isTrue(foo3 is FunTakes<FutureOr<String>>);
+  Expect.isTrue(foo3 is FunTakes<FutureOr<FutureOr<Object>>>);
+  Expect.isTrue(foo3 is FunTakes<FutureOr<FutureOr<int>>>);
+  Expect.isTrue(foo3 is FunTakes<FutureOr<FutureOr<String>>>);
+
+  Expect.isTrue(bar3 is FunReturns<dynamic>);
+  Expect.isTrue(bar3 is FunReturns<Object>);
+  Expect.isTrue(bar3 is FunReturns<int>);
+  Expect.isFalse(bar3 is FunReturns<String>);
+  Expect.isFalse(bar3 is FunReturns<Future<int>>);
+  Expect.isFalse(bar3 is FunReturns<Future<String>>);
+  Expect.isTrue(bar3 is FunReturns<FutureOr<Object>>);
+  Expect.isTrue(bar3 is FunReturns<FutureOr<int>>);
+  Expect.isTrue(bar3 is FunReturns<FutureOr<String>>);
+  Expect.isTrue(bar3 is FunReturns<FutureOr<FutureOr<Object>>>);
+  Expect.isTrue(bar3 is FunReturns<FutureOr<FutureOr<int>>>);
+  Expect.isTrue(bar3 is FunReturns<FutureOr<FutureOr<String>>>);
+}