Recursive shallow copy

copy.js

function recursiveShallowCopy(target, source) {
    const isObject = (obj) => obj && typeof obj === 'object';
    if (!isObject(target) || !isObject(source)) {
        return source;
    }
    
    for (const [key, value] of Object.entries(source)) {
        if (Array.isArray(value)) {
            target[key] = recursiveShallowCopy([], value)
        } else if (isObject(value)) {
            target[key] = recursiveShallowCopy({}, value);
        } else {
            target[key] = value;
        }
    }

    return target;
}