checker/tests/nullness/java8/methodref/ReceiversMethodref.java

import org.checkerframework.checker.nullness.qual.*;

// Nullable receivers don't make a lot of sense
// But this class tests the sub supertype recevier relationships.
// It could just use tainted.

interface Unbound1 {
  void apply(@NonNull MyClass my);
}

interface Unbound2 {
  void apply(@Nullable MyClass my);
}

interface Supplier1<R extends @Nullable Object> {
  R supply();
}

interface Bound {
  void apply();
}

class MyClass {
  // :: error: (nullness.on.receiver)
  void take(@NonNull MyClass this) {}

  // :: error: (nullness.on.receiver)
  void context1(@Nullable MyClass this, @NonNull MyClass my1, @Nullable MyClass my2) {

    Unbound1 u1 = MyClass::take;
    // :: error: (methodref.receiver)
    Unbound2 u2 = MyClass::take;

    Bound b1 = my1::take;
    // :: error: (methodref.receiver.bound)
    Bound b2 = my2::take;

    // :: error: (methodref.receiver.bound)
    Bound b11 = this::take;
  }

  // :: error: (nullness.on.receiver)
  void context2(@NonNull MyClass this) {
    Bound b21 = this::take;
  }

  class MySubClass extends MyClass {

    // :: error: (nullness.on.receiver)
    void context1(@Nullable MySubClass this) {
      // :: error: (methodref.receiver.bound)
      Bound b = super::take;
    }

    // :: error: (nullness.on.receiver)
    void context2(@NonNull MySubClass this) {
      Bound b = super::take;
    }

    class Nested {
      // :: error: (nullness.on.receiver)
      void context1(@Nullable Nested this) {
        // :: error: (methodref.receiver.bound)
        Bound b = MySubClass.super::take;
      }

      // :: error: (nullness.on.receiver)
      void context2(@NonNull Nested this) {
        Bound b = MySubClass.super::take;
      }
    }
  }
}

class Outer {
  class Inner1 {
    // :: error: (nullness.on.receiver)
    Inner1(@Nullable Outer Outer.this) {}
  }

  class Inner2 {
    // :: error: (nullness.on.receiver)
    Inner2(@NonNull Outer Outer.this) {}
  }

  // :: error: (nullness.on.receiver)
  void context(@Nullable Outer this) {
    // This one is unbound and needs an Outer as a param
    Supplier1<Inner1> f1 = Inner1::new;
    // :: error: (methodref.receiver.bound)
    Supplier1<Inner2> f2 = Inner2::new;

    // Supplier1</*3*/Inner> f = /*4*/Inner::new;
    // 4 <: 3? Constructor annotations?
  }
}