[GROOVY-10217] Type inference does not work with GDK class enhancements

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.8
• Fix Version/s: 4.0.0-beta-2, 2.5.19, 3.0.13
• Component/s: Static Type Checker
• Assignee: Eric Milles
• Reporter: Svatopluk Dedic
• Created: 08/Sep/21 15:21
• Updated: 26/Aug/22 19:42
• Resolved: 09/Sep/21 16:03

Description

Consider the following code:

 

@groovy.transform.TypeChecked
public class T2 {
    def m(Object v) {
        if (v instanceof List) {
            System.err.println v.get(1)
            List x = (List)v;
            System.err.println x[0]
            //System.err.println v[0]           <--- Uncoment to get error
        } else {
            System.err.println "Not a list"
        }
    }
}

T2 t = new T2();
t.m(Arrays.asList("a", "b"));

This code compiles. But when the marked line is uncommented, groovy produces an error:

/tmp/g/ee/T.groovy: 9: [Static type checking] - Cannot find matching method java.lang.Object#getAt(int). Please check if the declared type is correct and if the method exists.
@ line 9, column 32.
              System.err.println v[0]

Basic inference works OK, as the v.get(int) call compiles, but seems the GDK enhancements (List.getAt which interfaces with the [] operator) are not considered.

Tested on Groovy Version: 3.0.8 JVM: 11.0.5 Vendor: Oracle Corporation OS: Linux