[GROOVY-11035] Inferred type is Object when having a complex inheritance chain of interfaces

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Duplicate
• Component/s: Static Type Checker
• Assignee: Eric Milles
• Reporter: Thodoris Sotiropoulos
• Created: 28/Apr/23 08:53
• Updated: 22/Dec/23 11:38
• Resolved: 30/Apr/23 14:32

Description

This seems related to GROOVY-11012.

I have the following program

@Grab('org.apache.commons:commons-collections4:4.4')
import org.apache.commons.collections4.iterators.*;

class Main {
  @groovy.transform.TypeChecked test() {
    EmptyListIterator<Number> tmp = null
    Number x = tmp.next()
  }
}

Actual behavior

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
test.groovy: 6: [Static type checking] - Cannot assign value of type java.lang.Object to variable of type java.lang.Number
 @ line 6, column 16.
       Number x = tmp.next();
                  ^

1 error

Expected behavior

Compile successfully

Notes

Tested against master (commit: ed4b33c8d5ac71ee4963d6bb391850593c59e5b1)

https://commons.apache.org/proper/commons-collections/javadocs/api-4.4/org/apache/commons/collections4/iterators/EmptyListIterator.html

Issue Links

• is related to: GROOVY-8638 CompileStatic fails with Guava Multimap#asMap
• is related to: GROOVY-10109 IllegalAccessError with package-access base class
• is related to: GROOVY-10120 STC: Guava Multimap#asMap bridge method
• is related to: GROOVY-10136 [JDK16] Failed to find `public` method derived from `package` super class
• is related to: GROOVY-11012 Wrong type is inferred when calling method defined in the parent class