Simple Queue data structure in TypeScript

q.ts

class Queue<T> {
  private list: T[] = [];
  private readonly capacity: number | null = null;
  private tail = 0;
  private head = 0;

  constructor(capacity: number) {
    this.capacity = Math.max(capacity, 0) || null;

    if (this.capacity) {
      this.list = Array.from<T>({ length: this.capacity });
    }
  }

  get size(): number {
    return this.tail - this.head;
  }

  get isEmpty(): boolean {
    return this.size === 0;
  }

  get isFull(): boolean {
    if (this.capacity) {
      return this.tail === this.capacity;
    }

    return false;
  }

  enqueue(item: T) {
    if (!this.isFull) {
      this.list[this.tail] = item;
      this.tail += 1;
    }

    return this.size;
  }

  dequeue() {
    let item = null;

    if (!this.isEmpty) {
      item = this.list[this.head];
      delete this.list[this.head];
      this.head += 1;

      if (this.isEmpty) {
        this.head = 0;
        this.tail = 0;
      }
    }

    return item;
  }

  peek() {
    if (this.isEmpty) {
      return null;
    }
    return this.list[this.head];
  }

  clear() {
    if (this.capacity) {
      this.list = Array.from<T>({ length: this.capacity });
    } else {
      this.list = [];
    }

    this.head = 0;
    this.tail = 0;
  }

  print() {
    const list: T[] = [];

    this.list.forEach((item) => {
      list.push(item);
    });

    console.log(list);
  }

  toString() {
    if (this.isEmpty) {
      return '';
    }

    let str = `${this.list[this.head]}`;

    for (let i = this.head + 1; i < this.tail; i++) {
      str += `, ${this.list[i]}`;
    }

    return str;
  }
}

const q = new Queue<number>(2);
q.enqueue(1);
q.enqueue(2);
q.print()