Trie in Typescript

trie.ts

class TrieNode {
    parent: TrieNode | null;
    children: any = {}
    key: string | null;
    isTerminating = false

    constructor(key: string | null, parent: TrieNode | null) {
        this.key = key;
        this.parent = parent
    }
}

class Trie {
    private root = new TrieNode(null, null)

    insert(list: string[]) {
        let current = this.root;

        list.forEach((element) => {
            if (current.children[element] == null) {
                current.children[element] = new TrieNode(element, current)
            }
            current = current.children[element]
        });

        current.isTerminating = true
    }

    contains(list: string[]): Boolean {
        let current = this.root;

        list.forEach((element) => {
            let child = current.children[element];
            console.log(child.key);
            if (child == null) {
                return false;
            }
            current = child
        });

        return current.isTerminating
    }
}

const trie = new Trie()
trie.insert("alex".split(""));
trie.insert("ali".split(""));
trie.insert("darcy".split(""));
trie.insert("estyn".split(""));
trie.insert("ian".split(""));
trie.insert("ivan".split(""));
trie.insert("josh".split(""));
trie.insert("mark".split(""));
trie.insert("michele".split(""));
trie.insert("robin".split(""));
trie.insert("sunny".split(""));
trie.insert("steven".split(""));

const alex = trie.contains("alex".split(""))
console.log(alex)

const steven = trie.contains("steven".split(""));
console.log(steven)

const ale = trie.contains("ale".split(""))
console.log(ale)