Elimate Code Duplication in DefaultRedisList

[kjb512]

There is code duplication in the DefaultRedisList methods. Specifically, the usage of listOps.rightPush/leftPush followed by a call to cap() is repeated in multiple places. This can be refactored to enhance code maintainability and readability.

    @Override
    public boolean add(E value) {
        listOps.rightPush(value);
        cap();
        return true;
    }

    @Override
    public boolean offer(E element) {
        listOps.rightPush(element);
        cap();
        return true;
    }

    @Override
    public void addFirst(E element) {
        listOps.leftPush(element);
        cap();
    }

    @Override
    public void add(int index, E element) {

        if (index == 0) {
            listOps.leftPush(element);
            cap();
            return;
        }

        int size = size();

        if (index == size()) {
            listOps.rightPush(element);
            cap();
            return;
        }

        if (index < 0 || index > size) {
            throw new IndexOutOfBoundsException();
        }

        throw new IllegalArgumentException("Redis supports insertion only at the beginning or the end of the list");
    }

Proposed Solution:

To enhance consistency and readability, I propose refactoring the method names to addFirst and addLast. This will provide a clear indication of where the element is being added, compared to the more generic add.

AS-IS

    @Override
    public void add(int index, E element) {

        if (index == 0) {
            listOps.leftPush(element);
            cap();
            return;
        }

        int size = size();

        if (index == size()) {
            listOps.rightPush(element);
            cap();
            return;
        }

        if (index < 0 || index > size) {
            throw new IndexOutOfBoundsException();
        }

        throw new IllegalArgumentException("Redis supports insertion only at the beginning or the end of the list");
    }

TO-BE

    @Override
    public void add(int index, E element) {

        if (index == 0) {
            addFirst(element);
            return;
        }

        int size = size();

        if (index == size()) {
            addLast(element);
            return;
        }

        if (index < 0 || index > size) {
            throw new IndexOutOfBoundsException();
        }

        throw new IllegalArgumentException("Redis supports insertion only at the beginning or the end of the list");
    }