[GROOVY-10890] Generics regression in method call

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0.7
• Fix Version/s: 2.5.21, 3.0.15, 4.0.8
• Component/s: Static Type Checker
• Labels: generics regression
• Assignee: Eric Milles
• Reporter: Christopher Smith
• Created: 30/Dec/22 22:26
• Updated: 10/Feb/23 21:40
• Resolved: 02/Jan/23 04:15

Description

I'm receiving a compile-time error on an invocation that is semantically correct and worked in 4.0.6. When using the EnumMap copy constructor, the STC appears to misinfer the type as <V, V> instead of <K, V>. The problem seems to present itself only when V is also an enum type (of course, K must be an enum type).

@CompileStatic
class Example {

    enum Foo {}
    enum Bar {}

    void run(Map<Foo, Bar> input) {
        error(new EnumMap<>(input))  // error here
    }

    void error(Map<Foo, Bar> input) {
    }
}

Groovy:[Static type checking] - Cannot call Example#error(java.util.Map<Example.Foo, Example.Bar>) with arguments [java.util.EnumMap<Example.Bar, Example.Bar>]