MutableContext / MutableStructure equality bug

[glissand0]

MutableContext stores a MutableStructure instance, which uses Lombok's @EqualsAndHashCode. Using IntelliJ's delombok, this is the generated code

public boolean equals(final Object o) {
      if (o == this) {
          return true;
      }
      if (!(o instanceof MutableStructure)) {
          return false;
      }
      final MutableStructure other = (MutableStructure) o;
      if (!other.canEqual((Object) this)) {
          return false;
      }
      return true;
  }

  protected boolean canEqual(final Object other) {return other instanceof MutableStructure;}

  public int hashCode() {
      int result = 1;
      return result;
  }

ie, all MutableStructure objects will be treated as equal and the below tests pass

    @Test
    void mutableStructureEquality() {
        MutableStructure m1 = new MutableStructure();
        m1.add("key1", "val1");
        MutableStructure m2 = new MutableStructure();
        m1.add("key2", "val2");
        assertEquals(m1, m2);
    }

    @Test
    void mutableCtxEquality() {
        final Map<String, Value> attributes = new HashMap<>();
        attributes.put("key1", new Value("val1"));
        final MutableContext ctx = new MutableContext(attributes);

        final Map<String, Value> attributes2 = new HashMap<>();
        final MutableContext ctx2 = new MutableContext(attributes2);

        assertThat(ctx).isEqualTo(ctx2);
    }

This is Lombok's behaviour when a class does not contain any attributes, regardless of what is in the parent class (see, eg https://medium.com/vena-engineering/the-inheritance-hashset-related-bug-with-lombok-36dbcfb04381)

This can be fixed by changing the equality annotation on MutableStructure to @EqualsAndHashCode(callSuper = true)

On a related note, ImmutableContext does not override equals at all. This could be the intention, but I think it would be useful if it did?