Shapes::keyExists should refine optional shape fields #8012

Activity

1. fredemmott commented on Sep 29, 2017

   

   fredemmott

   on Sep 29, 2017

   Contributor

   More actions

   The PHP error control operator is not part of hack, and we don't plan on adding it. See https://docs.hhvm.com/hack/typechecker/special for ways to suppress this.
2. michaeltingley commented on Sep 29, 2017

   

   michaeltingley

   on Sep 29, 2017

   More actions

   Seems like a reasonable request, I'll see what we can do.
3. fredemmott

   added

   hack

   on Sep 29, 2017
4. dlreeves commented on Oct 4, 2017

   

   dlreeves

   on Oct 4, 2017

   Contributor

   More actions

   We plan on making changes to Hack that will better define when and how type refinement will be performed. We hadn't considered this case, but we will take this use case in mind for the change. I rather focus our attention on the future, especially since we hope to get the feature out within the next 3-6 months.

   If there was a pull request that made the change I would consider merging it, but not something anyone on the team will work on at the moment.
5. ryangreenberg commented on Jul 25, 2018

   

   ryangreenberg

   on Jul 25, 2018

   More actions

   I think this issue can be closed with the release of 3.27:

   In 3.27.1 Shapes::keyExist() now refines the type when used as a condition

   🎉React with 🎉1Reacted by Fred Emmott
6. fredemmott

   closed this as completedon Jul 25, 2018
7. eryi commented on Jul 29, 2018

   

   eryi

   on Jul 29, 2018

   Last edited by eryi

   Author

   More actions

   For some reason, this doesn't work with invariant. Is this expected?

   <?hh //strict
   
   function myfunc(shape(?'optional' => string) $var): void {
     \invariant(Shapes::keyExists($var, 'optional'), '');
   
     // Invalid index operation: 'optional' is marked as an optional shape field....
     print $var['optional'];
   }
   
   function myfunc2(shape(?'optional' => string) $var): void {
     if (!Shapes::keyExists($var, 'optional')) throw new Exception();
   
     // OK
     print $var['optional'];
   }

   hh_client

   Invalid index operation: 'optional' is marked as an optional shape field. It may not be present in the shape. Use the `??` operator instead. (Typing[4165])
   

   hhvm --version

   HipHop VM 3.27.1 (rel)
   Compiler: 1532025848_857759529
   Repo schema: 6f2a65dfa3a360d8c159fe76a8bee0e26ba4e45a
   
8. eryi commented on Jul 29, 2018

   

   eryi

   on Jul 29, 2018

   Author

   More actions

   This might be asking too much of the type checker but it would be nice if this worked on more than 1 level.

   <?hh //strict
   function myfunc(shape(?'optional' => shape(?'optional' => string)) $var): void {
     if (!Shapes::keyExists($var, 'optional')) throw new Exception();
     if (!Shapes::keyExists($var['optional'], 'optional')) throw new Exception();
   
     // Invalid index operation: 'optional' is marked as an optional shape field....
     print $var['optional']['optional'];
   }

   👍React with 👍1Reacted by 1samekhan