queue-typed/test/index.test.ts

Queue data structure

import {LinkedListQueue, Queue} from '../src';

describe('Queue Operation Test', () => {
    it('should validate a queue', () => {
        const queue = new Queue<number>();
        for (let i = 0; i < 1000; i++) {
            queue.enqueue(i);
        }
        let last: number | undefined = 0;
        for (let i = 0; i < 1000; i++) {
            last = queue.dequeue();
        }
        expect(last).toBe(999);
    });
});

describe('Queue', () => {
    let queue: Queue<number>;

    beforeEach(() => {
        queue = new Queue<number>();
    });

    it('should initialize an empty queue', () => {
        expect(queue.size).toBe(0);
    });

    it('should push elements to the end of the queue', () => {
        queue.push(1);
        queue.push(2);
        expect(queue.peek()).toBe(1);
        expect(queue.size).toBe(2);
    });

    // it('should shift elements from the front of the queue', () => {
    //   queue.push(1);
    //   queue.push(2);
    //   const shifted = queue.shift();
    //   expect(shifted).toBe(1);
    //   expect(queue.peek()).toBe(2);
    //   expect(queue.size).toBe(1);
    // });
    //
    // it('should peek at the front of the queue', () => {
    //   queue.push(1);
    //   queue.push(2);
    //   expect(queue.peek()).toBe(1);
    // });

    // Add more test cases for other methods of Queue.
});
describe('Queue', () => {
    let queue: Queue<number>;

    beforeEach(() => {
        queue = new Queue<number>();
    });

    it('should initialize an empty queue', () => {
        expect(queue.size).toBe(0);
        expect(queue.isEmpty()).toBe(true);
    });

    it('should push elements to the end of the queue', () => {
        queue.push(1);
        queue.push(2);
        expect(queue.size).toBe(2);
        expect(queue.peek()).toBe(1);
        expect(queue.peekLast()).toBe(2);
    });

    it('should shift elements from the front of the queue', () => {
        queue.push(1);
        queue.push(2);
        const shifted = queue.shift();
        expect(shifted).toBe(1);
        expect(queue.size).toBe(1);
        expect(queue.peek()).toBe(2);
        expect(queue.peekLast()).toBe(2);
    });

    it('should handle shifting when queue reaches half size', () => {
        for (let i = 1; i <= 5; i++) {
            queue.push(i);
        }
        for (let i = 1; i <= 3; i++) {
            queue.shift();
        }
        // Queue size should be 2, but internal array size is still 5.
        // Test that shifting optimizes the internal array.
        expect(queue.size).toBe(2);
        expect(queue.nodes.length).toBe(2);
        expect(queue.peek()).toBe(4);
    });

    it('should peek at the front and end of the queue', () => {
        queue.push(1);
        queue.push(2);
        expect(queue.peek()).toBe(1);
        expect(queue.peekLast()).toBe(2);
    });

    it('should handle shifting when the queue is empty', () => {
        const shifted = queue.shift();
        expect(shifted).toBeUndefined();
        expect(queue.size).toBe(0);
        expect(queue.peek()).toBeUndefined();
    });

    it('should handle peeking when the queue is empty', () => {
        expect(queue.peek()).toBeUndefined();
        expect(queue.peekLast()).toBeUndefined();
    });

    it('should handle clearing the queue', () => {
        for (let i = 1; i <= 3; i++) {
            queue.push(i);
        }
        queue.clear();
        expect(queue.size).toBe(0);
        expect(queue.peek()).toBeUndefined();
        expect(queue.peekLast()).toBeUndefined();
    });

    it('should clone the queue', () => {
        for (let i = 1; i <= 3; i++) {
            queue.push(i);
        }
        const clonedQueue = queue.clone();
        expect(clonedQueue.size).toBe(3);
        expect(clonedQueue.peek()).toBe(1);
        expect(clonedQueue.peekLast()).toBe(3);
    });

    it('should handle creating a queue from an array', () => {
        const elements = [1, 2, 3, 4, 5];
        const newQueue = Queue.fromArray(elements);
        expect(newQueue.size).toBe(5);
        expect(newQueue.peek()).toBe(1);
        expect(newQueue.peekLast()).toBe(5);
    });

    it('should iterate through the queue', () => {
        for (let i = 1; i <= 3; i++) {
            queue.push(i);
        }
        const values = Array.from(queue);
        expect(values).toEqual([1, 2, 3]);
    });
});
describe('LinkedListQueue', () => {
    let queue: LinkedListQueue<string>;

    beforeEach(() => {
        queue = new LinkedListQueue<string>();
    });

    it('should enqueue elements to the end of the queue', () => {
        queue.enqueue('A');
        queue.enqueue('B');
        expect(queue.peek()).toBe('A');
        expect(queue.length).toBe(2);
    });

    it('should dequeue elements from the front of the queue', () => {
        queue.enqueue('A');
        queue.enqueue('B');
        const dequeued = queue.dequeue();
        expect(dequeued).toBe('A');
        expect(queue.peek()).toBe('B');
        expect(queue.length).toBe(1);
    });

    it('should peek at the front of the queue', () => {
        queue.enqueue('A');
        queue.enqueue('B');
        expect(queue.peek()).toBe('A');
    });

    // Add more test cases for other methods of LinkedListQueue.
});