fn cmp_eq_chain()

in gazebo/src/cmp.rs [232:302]
66 lines of code
20 McCabe index (conditional complexity)

    fn cmp_eq_chain() {
        struct FakeComparable(
            Box<dyn Fn() -> Ordering>,
            Box<dyn Fn() -> Ordering>,
            Box<dyn Fn() -> Ordering>,
        );
        impl PartialEq for FakeComparable {
            fn eq(&self, _other: &Self) -> bool {
                eq_chain!(
                    (self.0)() == Ordering::Equal,
                    (self.1)() == Ordering::Equal,
                    (self.2)() == Ordering::Equal,
                )
            }
        }
        impl Eq for FakeComparable {}
        impl PartialOrd for FakeComparable {
            fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
                Some(self.cmp(other))
            }
        }
        impl Ord for FakeComparable {
            fn cmp(&self, _other: &Self) -> Ordering {
                cmp_chain! {
                    (self.0)(),
                    (self.1)(),
                    (self.2)(),
                }
            }
        }

        let fake = FakeComparable(
            Box::new(|| Ordering::Less),
            Box::new(|| unreachable!("should return less")),
            Box::new(|| unreachable!("should return less")),
        );
        assert_eq!(fake.cmp(&fake), Ordering::Less);
        assert_eq!(fake.eq(&fake), false);

        let fake = FakeComparable(
            Box::new(|| Ordering::Greater),
            Box::new(|| unreachable!("should return less")),
            Box::new(|| unreachable!("should return less")),
        );
        assert_eq!(fake.cmp(&fake), Ordering::Greater);
        assert_eq!(fake.eq(&fake), false);

        let fake = FakeComparable(
            Box::new(|| Ordering::Equal),
            Box::new(|| Ordering::Less),
            Box::new(|| unreachable!("should return less")),
        );
        assert_eq!(fake.cmp(&fake), Ordering::Less);
        assert_eq!(fake.eq(&fake), false);

        let fake = FakeComparable(
            Box::new(|| Ordering::Equal),
            Box::new(|| Ordering::Equal),
            Box::new(|| Ordering::Greater),
        );
        assert_eq!(fake.cmp(&fake), Ordering::Greater);
        assert_eq!(fake.eq(&fake), false);

        let fake = FakeComparable(
            Box::new(|| Ordering::Equal),
            Box::new(|| Ordering::Equal),
            Box::new(|| Ordering::Equal),
        );
        assert_eq!(fake.cmp(&fake), Ordering::Equal);
        assert_eq!(fake.eq(&fake), true);
    }