[GROOVY-6693] Compiler fails to infer type if given a concrete type instead of a generified interface

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3.0-beta-2
• Fix Version/s: 2.3.1
• Component/s: Static Type Checker
• Assignee: Jochen Theodorou
• Reporter: Cédric Champeau
• Created: 10/Apr/14 10:40
• Updated: 20/May/14 05:31
• Resolved: 12/May/14 05:15

Description

The following test case fails:

import groovy.transform.ASTTest
import static org.codehaus.groovy.transform.stc.StaticTypesMarker.*
import static org.codehaus.groovy.ast.ClassHelper.*

interface Converter<F, T> {
T convertC(F from)
}
  
class Holder<T> {
   T thing
  
   Holder(T thing) {
    this.thing = thing
   }
  
   def <R> Holder<R> convertH(Converter<? super T, ? extends R> func1) {
      new Holder(func1.convertC(thing))
   }
}

class IntToFloatConverter implements Converter<Integer,Float> {
    public Float convertC(Integer from) { from.floatValue() } 
}
 
@groovy.transform.TypeChecked
void foo() {
@ASTTest(phase=INSTRUCTION_SELECTION,value={
    def holderType = node.getNodeMetaData(INFERRED_TYPE)
    assert holderType.genericsTypes[0].type == Float_TYPE
})
def h1 = new Holder<Integer>(2).convertH(new IntToFloatConverter())
}
foo()

The important part is that when inference is done, it should map the placeholders from Converter<F,T> to the concrete implementations of IntToFloatConverter, that is to say Integer and Double.