checker/tests/nullness/Issue2432b.java

// Ensure correct handling of type parameters and arrays.
// https://github.com/typetools/checker-framework/issues/2432

import java.util.ArrayList;
import java.util.List;
import org.checkerframework.checker.nullness.qual.PolyNull;

public class Issue2432b {
  void objectAsTypeArg() {
    List<Object> objs = new ArrayList<>();
    // no error
    Object[] objarray = objs.toArray();
  }

  void myClassAsTypeArg() {
    MyClass<Object> objs = new MyClass<>();
    Object[] objarray = objs.toArray();
    // no error
    Object[] objarray2 = objs.toArrayPoly();
  }

  void stringAsTypeArg() {
    List<String> strs = new ArrayList<>();
    Object[] strarray = strs.toArray();
  }

  void listAsTypeArg() {
    List<List> lists = new ArrayList<>();
    Object[] listarray = lists.toArray();
  }

  private static class MyClass<MyTypeParam> {

    Object[] toArray() {
      return new Object[] {new Object()};
    }

    @PolyNull Object[] toArrayPoly(MyClass<@PolyNull MyTypeParam> this) {
      return new Object[] {new Object()};
    }
  }
}