Add tests for `FutureOr<T>`.

Add tests for `FutureOr<T>`.

R=lrn@google.com

Committed: https://github.com/dart-lang/sdk/commit/0c3deba6dfcc23edd1bff80c274ac63f7d719a93

[floitsch, 2016-12-08 15:34:53]

floitsch@google.com changed reviewers:
+ lrn@google.com

[floitsch, 2016-12-08 15:34:53]

I still need to update the status files.

[floitsch, 2016-12-08 17:45:51]

Updated the status file.

Note: this CL depends on https://codereview.chromium.org/2562703002/

[Lasse Reichstein Nielsen, 2016-12-08 18:20:29]

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
File tests/lib/async/future_or_bad_type_test.dart (right):

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_bad_type_test.dart:14: with FutureOr<bool>  /// with:
compile-time error
You need "extends Object with FutureOr<bool>". The "with" can't stand by itself.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_bad_type_test.dart:21: Expect.isTrue(499 is
FutureOr<Does<Not<Exist>>>);  /// 01: static type warning
Hmm. What is this intended to do, and why? 
The "Does" is malformed, so it is "499 is FutureOr<Malformed>" aka "499 is
Malformed | 499 is Future<Malformed>". 
(That is: Document expected behavior, anything with malformed types is hard to
remember for most of us :)

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
File tests/lib/async/future_or_non_strong_test.dart (right):

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:24: Expect.isTrue(499 is
FutureOr<String>);
is! or Expect.isFalse?

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:29: Expect.isTrue(new
Future.value(499) is FutureOr<String>);
This is spec mode, so it's a Future<dynamic> which is a Future<String>. Maybe
document that.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:56: 
You could move the declaration of foo2 down here so it's easier to see its type.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:59: Expect.isTrue(foo2 is
FunTakes<int>);
is!

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:61: Expect.isTrue(foo2 is
FunTakes<Future<int>>);
is!

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

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:73: Expect.isTrue(bar2 is
FunReturns<String>);
is!

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

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:84: Expect.isTrue(foo3 is
FunTakes<Object>);
is!
(Just figure out the rest :)

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
File tests/lib/async/future_or_strong_test.dart (right):

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_strong_test.dart:11: void foo(FutureOr x) {}  //
Equivalent to `void bar(Object x) {}`.
So this is a strong-mode only test?

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_strong_test.dart:12: FutureOr bar() => 499;  //
Equivalent to `Object foo() => null`.
=> 499?

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_strong_test.dart:46: // Is check treats `dynamic`
special in function types.
special -> specially
Sentence is hard to read. Also, it doesn't treat dynamic specially as a return
type, only as an argument type.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_strong_test.dart:64: Expect.isTrue(foo2 is
FunTakes<Object>);
isFalse. foo2 takes String or Future<String>, but not Object.

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

So should I add another comment explaining that one test is in strong mode and
the other one isn't?

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
File tests/lib/async/future_or_bad_type_test.dart (right):

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_bad_type_test.dart:14: with FutureOr<bool>  /// with:
compile-time error
On 2016/12/08 18:20:28, Lasse Reichstein Nielsen wrote:
> You need "extends Object with FutureOr<bool>". The "with" can't stand by
itself.

Done.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_bad_type_test.dart:21: Expect.isTrue(499 is
FutureOr<Does<Not<Exist>>>);  /// 01: static type warning
On 2016/12/08 18:20:28, Lasse Reichstein Nielsen wrote:
> Hmm. What is this intended to do, and why? 
> The "Does" is malformed, so it is "499 is FutureOr<Malformed>" aka "499 is
> Malformed | 499 is Future<Malformed>". 
> (That is: Document expected behavior, anything with malformed types is hard to
> remember for most of us :)

Added a comment.
  // FutureOr<T> should be treated like `dynamic`. Dynamically the `T` is
  // completely ignored. It can be a malformed type.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
File tests/lib/async/future_or_non_strong_test.dart (right):

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:24: Expect.isTrue(499 is
FutureOr<String>);
On 2016/12/08 18:20:28, Lasse Reichstein Nielsen wrote:
> is! or Expect.isFalse?

not in non-strong mode.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:29: Expect.isTrue(new
Future.value(499) is FutureOr<String>);
On 2016/12/08 18:20:28, Lasse Reichstein Nielsen wrote:
> This is spec mode, so it's a Future<dynamic> which is a Future<String>. Maybe
> document that.

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?

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:56: 
On 2016/12/08 18:20:28, Lasse Reichstein Nielsen wrote:
> You could move the declaration of foo2 down here so it's easier to see its
type.

Done.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:59: Expect.isTrue(foo2 is
FunTakes<int>);
On 2016/12/08 18:20:28, Lasse Reichstein Nielsen wrote:
> is!

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

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:61: Expect.isTrue(foo2 is
FunTakes<Future<int>>);
On 2016/12/08 18:20:28, Lasse Reichstein Nielsen wrote:
> is!
> 
> More below (everyone except Future<String>, FutureOr<String> and
> FutureOr<FutureOr<String>>)

Same answer.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:73: Expect.isTrue(bar2 is
FunReturns<String>);
On 2016/12/08 18:20:28, Lasse Reichstein Nielsen wrote:
> is!
> 
> Same for Future<String>, FutureOr<String>, and FuturOr<FutureOr<String>>.

Same answer.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:84: Expect.isTrue(foo3 is
FunTakes<Object>);
On 2016/12/08 18:20:28, Lasse Reichstein Nielsen wrote:
> is!
> (Just figure out the rest :)

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

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
File tests/lib/async/future_or_strong_test.dart (right):

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_strong_test.dart:11: void foo(FutureOr x) {}  //
Equivalent to `void bar(Object x) {}`.
On 2016/12/08 18:20:29, Lasse Reichstein Nielsen wrote:
> So this is a strong-mode only test?

Yes. As hinted by the name and the description on the top of the file.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_strong_test.dart:12: FutureOr bar() => 499;  //
Equivalent to `Object foo() => null`.
On 2016/12/08 18:20:29, Lasse Reichstein Nielsen wrote:
> => 499?

Done.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_strong_test.dart:46: // Is check treats `dynamic`
special in function types.
On 2016/12/08 18:20:29, Lasse Reichstein Nielsen wrote:
> special -> specially
> Sentence is hard to read. Also, it doesn't treat dynamic specially as a return
> type, only as an argument type.

Done.

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_strong_test.dart:64: Expect.isTrue(foo2 is
FunTakes<Object>);
On 2016/12/08 18:20:29, Lasse Reichstein Nielsen wrote:
> isFalse. foo2 takes String or Future<String>, but not Object.

Done.

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

Once at the top of each file is enough, as long as it stands out ("NOTICE:" or
"STRONG MODE" might do it).

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
File tests/lib/async/future_or_non_strong_test.dart (right):

https://codereview.chromium.org/2564563003/diff/60001/tests/lib/async/future_...
tests/lib/async/future_or_non_strong_test.dart:29: Expect.isTrue(new
Future.value(499) is FutureOr<String>);
No, that's just me being too used to think of FutureOr in strong mode. Once is
enough.

[Lasse Reichstein Nielsen, 2016-12-12 13:21:55]

lgtm

https://codereview.chromium.org/2564563003/diff/120001/tests/lib/lib.status
File tests/lib/lib.status (right):

https://codereview.chromium.org/2564563003/diff/120001/tests/lib/lib.status#n...
tests/lib/lib.status:15: async/future_or_strong_test: RuntimeError, OK
Should this be skipped if not in strong mode?

[floitsch, 2016-12-12 13:55:03]

Description was changed from

==========
Add tests for `FutureOr<T>`.
==========

to

==========
Add tests for `FutureOr<T>`.

R=lrn@google.com

Committed:
https://github.com/dart-lang/sdk/commit/0c3deba6dfcc23edd1bff80c274ac63f7d719a93
==========

[floitsch, 2016-12-12 13:55:05]

Committed patchset #7 (id:120001) manually as
0c3deba6dfcc23edd1bff80c274ac63f7d719a93 (presubmit successful).