import { DoubleLinkedList } from "./index.js";

describe('testing DoubleLinkedList file', () => {
    let newList: any
    beforeEach(() => {
        newList = new DoubleLinkedList()
    })

    test('new DoubleLinkedList()', () => {
        expect(JSON.stringify(newList)).toBe(JSON.stringify(new DoubleLinkedList()));
    });
    
    test('DoubleLinkedList.push()', () => {
        newList.push(1)
        expect(newList.head.data).toBe(1)
        newList.push(2)
        expect(newList.tail.data).toBe(2)
        expect(newList.head.data).toBe(1)
    })

    test('DoubleLinkedList.first()', () => {
        expect(newList.first()).toBe(undefined)
        newList.push(1)
        expect(newList.first()).toBe(1)
        newList.push(undefined)
        expect(newList.head.next.data).toBe(undefined)
    })

    test('DoubleLinkedList.toArray()', () => {
        expect(JSON.stringify(newList.toArray())).toBe(JSON.stringify([]))
        newList.push(null)
        expect(JSON.stringify(newList.toArray())).toBe(JSON.stringify([null]))
        newList.push(1)
        expect(JSON.stringify(newList.toArray())).toBe(JSON.stringify([null,1]))
    })

    test('DoubleLinkedList.last()', () => {
        expect(newList.last()).toBe(undefined)
        newList.push(3)
        expect(newList.last()).toBe(3)
        newList.push(4)
        expect(newList.last()).toBe(4)
        newList.push(undefined)
        expect(newList.last()).toBe(undefined)
    })

    test('DoubleLinkedList.unshift()', () => {
        newList.unshift(0)
        expect(JSON.stringify(newList.first())).toBe(JSON.stringify(0))
        newList.unshift(1)
        expect(JSON.stringify(newList.first())).toBe(JSON.stringify(1))
        expect(JSON.stringify(newList.toArray())).toBe(JSON.stringify([1,0]))
        newList.unshift(undefined)
        expect(JSON.stringify(newList.toArray())).toBe(JSON.stringify([undefined,1,0]))
    })

    test('DoubleLinkedList.pop()', () => {
        expect(newList.pop()).toBe(undefined)
        newList.push(0)
        expect(newList.pop()).toBe(0)
        newList.push(1)
        newList.push(2)
        expect(newList.pop()).toBe(2)
    })

    test('DoubleLinkedList.shift()', () => {
        expect(newList.shift()).toBe(undefined)
        newList.push(1)
        newList.push(2)
        expect(newList.shift()).toBe(1)
    })

    test('DoubleLinkedList.fromArray()',()=>{
        newList.fromArray([])
        expect(JSON.stringify(newList.toArray())).toBe(JSON.stringify([]))
        newList.fromArray([1,2,3,4])
        expect(JSON.stringify(newList.toArray())).toBe(JSON.stringify([1,2,3,4]))
        newList.fromArray([undefined, undefined])
        expect(JSON.stringify(newList.toArray())).toBe(JSON.stringify([undefined, undefined]))
    })

    test('DoubleLinkedList.clear()',()=>{
        newList.fromArray([1,2,3,4,3,1,1,1,4])
        newList.clear()
        expect(JSON.stringify(newList.toArray())).toBe(JSON.stringify([]))

    })
});