fix #26334, allow supertypes for async function returns in strong mode

fix #26334, allow supertypes for async function returns in strong mode

R=brianwilkerson@google.com, leafp@google.com

Committed: https://github.com/dart-lang/sdk/commit/d4a81f12fb3dd61886caa92ffc9a19c93c392b09

[Jennifer Messerly, 2016-04-28 00:03:38]

jmesserly@google.com changed reviewers:
+ brianwilkerson@google.com, leafp@google.com

[Jennifer Messerly, 2016-04-28 00:03:39]

I think this is the fix for https://github.com/dart-lang/sdk/issues/26334. Does
it make sense? Are the tests in the right place?

[Leaf, 2016-04-28 01:01:50]

LGTM, thanks John.

https://codereview.chromium.org/1924113002/diff/1/pkg/analyzer/lib/src/genera...
File pkg/analyzer/lib/src/generated/error_verifier.dart (right):

https://codereview.chromium.org/1924113002/diff/1/pkg/analyzer/lib/src/genera...
pkg/analyzer/lib/src/generated/error_verifier.dart:3487: returnType.element !=
expectedType.element) {
This is a little tricky.  It might be clearer just to check that Future<bottom>
<: returnType.  But that's a bit hard to fit into the general helper function.  
So maybe just document that we're checking:

// If Future<dynamic> <: returnType, then returnType is Future<dynamic>, Object,
or dynamic, so we're good
// otherwise, check that returnType is Future<Something>

[Jennifer Messerly, 2016-04-28 01:25:05]

thanks! PTAL

https://codereview.chromium.org/1924113002/diff/1/pkg/analyzer/lib/src/genera...
File pkg/analyzer/lib/src/generated/error_verifier.dart (right):

https://codereview.chromium.org/1924113002/diff/1/pkg/analyzer/lib/src/genera...
pkg/analyzer/lib/src/generated/error_verifier.dart:3487: returnType.element !=
expectedType.element) {
On 2016/04/28 01:01:50, Leaf wrote:
> This is a little tricky.  It might be clearer just to check that
Future<bottom>
> <: returnType.  But that's a bit hard to fit into the general helper function.
 
> So maybe just document that we're checking:
> 
> // If Future<dynamic> <: returnType, then returnType is Future<dynamic>,
Object,
> or dynamic, so we're good
> // otherwise, check that returnType is Future<Something>

DOH. Yes, Future<bottom> is what I should've done. Thanks! :)

[Brian Wilkerson, 2016-04-28 03:36:04]

lgtm

[Leaf, 2016-04-28 05:23:33]

still lgtm

[Jennifer Messerly, 2016-04-28 16:57:10]

Description was changed from

==========
fix #26334, allow supertypes for async function returns in strong mode
==========

to

==========
fix #26334, allow supertypes for async function returns in strong mode

R=brianwilkerson@google.com, leafp@google.com

Committed:
https://github.com/dart-lang/sdk/commit/d4a81f12fb3dd61886caa92ffc9a19c93c392b09
==========

[Jennifer Messerly, 2016-04-28 16:57:12]

Committed patchset #3 (id:40001) manually as
d4a81f12fb3dd61886caa92ffc9a19c93c392b09 (presubmit successful).