[GROOVY-9997] STC: cast or coerce to functional interface fails to infer param types of closure/lambda

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.0-alpha-3, 3.0.9, 2.5.16
• Assignee: Eric Milles
• Reporter: Eric Milles
• Created: 23/Mar/21 00:12
• Updated: 22/Jun/22 14:08
• Resolved: 24/Mar/21 14:46

Description

Variation of GROOVY-9977. Consider the following:

@groovy.transform.TypeChecked
def stc() {
  return (Comparator<Integer>) { a, b -> Integer.compare(a, b) }
}

When casting or coercing a closure/lambda expression the type checker fails to infer the parameter types.

[Static type checking] - Cannot find matching method java.lang.Integer#compare(java.lang.Object, java.lang.Object). Please check if the declared type is correct and if the method exists.

Issue Links

• relates to: GROOVY-10660 STC: infer closure/lambda parameter types for return expression