checker/tests/nullness/java8/Issue1046Java8.java

// Test case for Issue 1046:
// https://github.com/typetools/checker-framework/issues/1046
// Additonal test case: checker/tests/nullness/Issue1046.java

import java.util.List;
import java.util.function.Function;
import org.checkerframework.checker.nullness.qual.UnknownKeyFor;

public class Issue1046Java8 {
  interface EnumMarker {}

  enum MyEnum implements EnumMarker {
    A,
    B;
  }

  static class NS2Lists {
    @SuppressWarnings("nullness")
    static <F, T> List<T> transform(List<F> p, Function<? super F, ? extends T> q) {
      return null;
    }

    static <F, T> List<F> transform2(List<F> p, Function<? super F, ? extends T> q) {
      return p;
    }
  }

  abstract class NotSubtype2 {
    void test(List<MyEnum> p) {
      NS2Lists.transform2(p, foo());
      NS2Lists.transform(p, foo());
    }

    abstract Function<? super @UnknownKeyFor EnumMarker, Number> foo();
  }
}