[GROOVY-10114] Wrong type argument inference when using the result of ternary operator directly.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.0.0-alpha-2, 3.0.8
• Fix Version/s: 4.0.2, 2.5.19, 3.0.13
• Component/s: Static compilation, Static Type Checker
• Assignee: Eric Milles
• Reporter: Stefanos Chaliasos
• Created: 27/May/21 11:35
• Updated: 03/Sep/22 23:50
• Resolved: 15/Mar/22 20:59

Description

I have the following Groovy program.

@groovy.transform.TypeChecked
class Test {
  public static void main(String[] args) {
    def x = ((false) ? new B<>(new A()) : new B<>(new A()))
    x.bar.foo()
    ((false) ? new B<A>(new A()) : new B<>(new A())).bar.foo()
    ((false) ? new B<>(new A()) : new B<>(new A())).bar.foo()
  }
}

final class A {
  public A() {
  }

  final Character foo() {
    (Character) 'g'
  }
}

class B<V> {
  public V bar

  public B(V bar) {
    this.bar = bar
  }
}

Actual Behavior

The program does not compile, and I get the following error.

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
Test.groovy: 7: [Static type checking] - Cannot find matching method java.lang.Object#foo(). Please check if the declared type is correct and if the method exists.
 @ line 7, column 5.
       ((false) ? new B<>(new A()) : new B<>(new A())).bar.foo()
       ^

1 error

Expected Behavior

Compile successfully.

Comment

This bug seems similar to GROOVY-9983, but it doesn't use subtyping. Moreover, in versions 3.0.8 and 4.0.0-alpha-2, the compiler produces the following error (in addition to the previous error message).

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
Test.groovy: 5: [Static type checking] - Cannot find matching method java.lang.Object#foo(). Please check if the declared type is correct and if the method exists.
 @ line 5, column 5.
       x.bar.foo()
       ^

Affected Version

This programs have been tested with the compiler from the master (commit: c36c8bf3d24ce41e972e3f3e7a5763acf96f46b1), 4.0.0-alpha-2, and 3.0.8.

Issue Links

• relates to: GROOVY-10614 Fail to infer the correct type argument when having conditionals and diamond operator