Case-insensitive Lodash-esque _.get() and _.unset()

iget_iunset.js

// like lodash _.get() but key lookup is case-insensitive
const iget = (value, prop, defaultValue) => {
    if (_.isPlainObject(value)) {
        if (_.isString(prop) && prop !== '') {
            return iget(value, prop.split('.'), defaultValue);
        } else if (_.isArray(prop) && prop.length) {
            const key = _.toLower(prop.shift()),
                val = Object.keys(value).reduce((a, k) => {
                    if (a !== undefined) {
                        return a;
                    }
                    if (_.toLower(k) === key) {
                        return value[k];
                    }
                }, undefined);
            if (prop.length) {
                let v = iget(val, prop, defaultValue);
                return v === undefined ? defaultValue : v;
            }
            return val === undefined ? defaultValue : val;
        }
    }
    return defaultValue;
};

// like lodash _.unset() but key lookup is case-insensitive
const iunset = (value, prop) => {
    if (_.isPlainObject(value)) {
        if (_.isString(prop) && prop !== '') {
            iunset(value, prop.split('.'));
        } else if (_.isArray(prop) && prop.length) {
            const key = _.toLower(prop.shift()),
                val = Object.keys(value).reduce((a, k) => {
                    if (a !== undefined) {
                        return a;
                    }
                    if (_.toLower(k) === key) {
                        if (0 === prop.length) {
                            delete value[k];
                        }
                        else {
                            return value[k];
                        }
                    }
                }, undefined);

            if (prop.length) iunset(val, prop);
        }
    }
};