[GROOVY-6800] Compilation error when calling method that has Optional<Closure> parameter

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3.0, 2.4.0-rc-1
• Fix Version/s: 2.3.11, 2.4.2
• Component/s: Static Type Checker
• Assignee: Cédric Champeau
• Reporter: Rob Fletcher
• Created: 19/May/14 03:39
• Updated: 14/Dec/15 18:08
• Resolved: 14/Dec/15 18:07

Description

I'm seeing a strange issue where if I try to call a method with an Optional<Closure> parameter from a type-checked context using Optional.of(someClosure) I get a compilation error. Other type parameters work fine in the same context and weirdly so does Optional.absent().

I've attached 3 scripts that demonstrate the problem.

• FailingWithClosure.groovy shows the problem occurring. I have a method that accepts Optional<Closure> and two statically compiled methods that call it, one with Optional.of(someClosure) and one with Optional.absent().
• WorkingWithString.groovy is the same code but with String type parameters instead of Closure. It works fine.
• WorkingWithClosureAndCast.groovy shows that if I explicitly cast the argument to Optional<Closure> it works.