ahmedgaafer/JS-Data-Structures

import { Stack } from ".";

describe("Stack tests 1", () => {
    it("Constructor 1", () => {
        const s = new Stack<number>();
        expect(s).toBeDefined();
    });

    it("Constructor 2", () => {
        const s = new Stack<number>([1, 2, 3, 4]);
        expect(s).toBeDefined();
    });

    it("push", () => {
        const s = new Stack<number>();
        s.push(1).push(2).push(3);

        expect(s.data[0]).toBe(1);
    });

    it("pop", () => {
        const s = new Stack<number>();
        s.push(1).pop();
        expect(s.data.length).toBe(0);
    });

    it("Peak", () => {
        const s = new Stack<number>();
        expect(s.push(1).peak()).toBe(1);
    });

    it("Viewing the stack", () => {
        const consoleSpy = jest.spyOn(console, "log");
        const s = new Stack<number>();
        s.push(1).push(2).push(3).view();

        expect(consoleSpy).toHaveBeenCalledTimes(1);
    });

    it("getSize", () => {
        const s = new Stack<number>();
        s.push(1).push(2).push(3);

        expect(s.getSize()).toBe(3);

        s.pop().pop();

        expect(s.getSize()).toBe(1);
    });
});

describe("Stack tests 2", () => {
    it("pop from empty Stack", () => {
        const s = new Stack<number>();
        expect(() => s.pop()).toThrow("Can not remove from an empty stack.");
    });

    it("peak an empty Stack", () => {
        const s = new Stack<number>();
        expect(() => s.peak()).toThrow("Can not peak an empty stack.");
    });

    it("view an empty stack", () => {
        const s = new Stack<number>();
        expect(() => s.view()).toThrow("Can not view an empty stack.");
    });
});