fn test_one_or_many_with_parens_value_into_iter()

in src/ast/mod.rs [9754:9829]

• 59 lines of code
• 7 McCabe index (conditional complexity)

    fn test_one_or_many_with_parens_value_into_iter() {
        use core::iter::once;

        //tests that our iterator implemented methods behaves exactly as it's inner iterator, at every step up to n calls to next/next_back
        fn test_steps<I>(ours: OneOrManyWithParens<usize>, inner: I, n: usize)
        where
            I: IntoIterator<Item = usize, IntoIter: DoubleEndedIterator + Clone> + Clone,
        {
            fn checks<I>(ours: OneOrManyWithParensIntoIter<usize>, inner: I)
            where
                I: Iterator<Item = usize> + Clone + DoubleEndedIterator,
            {
                assert_eq!(ours.size_hint(), inner.size_hint());
                assert_eq!(ours.clone().count(), inner.clone().count());

                assert_eq!(
                    ours.clone().fold(1, |a, v| a + v),
                    inner.clone().fold(1, |a, v| a + v)
                );

                assert_eq!(Vec::from_iter(ours.clone()), Vec::from_iter(inner.clone()));
                assert_eq!(
                    Vec::from_iter(ours.clone().rev()),
                    Vec::from_iter(inner.clone().rev())
                );
            }

            let mut ours_next = ours.clone().into_iter();
            let mut inner_next = inner.clone().into_iter();

            for _ in 0..n {
                checks(ours_next.clone(), inner_next.clone());

                assert_eq!(ours_next.next(), inner_next.next());
            }

            let mut ours_next_back = ours.clone().into_iter();
            let mut inner_next_back = inner.clone().into_iter();

            for _ in 0..n {
                checks(ours_next_back.clone(), inner_next_back.clone());

                assert_eq!(ours_next_back.next_back(), inner_next_back.next_back());
            }

            let mut ours_mixed = ours.clone().into_iter();
            let mut inner_mixed = inner.clone().into_iter();

            for i in 0..n {
                checks(ours_mixed.clone(), inner_mixed.clone());

                if i % 2 == 0 {
                    assert_eq!(ours_mixed.next_back(), inner_mixed.next_back());
                } else {
                    assert_eq!(ours_mixed.next(), inner_mixed.next());
                }
            }

            let mut ours_mixed2 = ours.into_iter();
            let mut inner_mixed2 = inner.into_iter();

            for i in 0..n {
                checks(ours_mixed2.clone(), inner_mixed2.clone());

                if i % 2 == 0 {
                    assert_eq!(ours_mixed2.next(), inner_mixed2.next());
                } else {
                    assert_eq!(ours_mixed2.next_back(), inner_mixed2.next_back());
                }
            }
        }

        test_steps(OneOrManyWithParens::One(1), once(1), 3);
        test_steps(OneOrManyWithParens::Many(vec![2]), vec![2], 3);
        test_steps(OneOrManyWithParens::Many(vec![3, 4]), vec![3, 4], 4);
    }