[JScore-JS-Adv-Lab: Unit Test] - 04. Add / Subtract

let calc;
let expect = require("chai").expect;

describe("createCalculator()", function() {
    beforeEach(function() {
        calc = require("../08-04.AddSubtract.js").createCalculator();
    });
    it("should return 5 after {add 3; add 2}", function() {
        calc.add(3); calc.add(2); let value = calc.get();
        expect(value).to.be.equal(5);
    });

    it("should return 0 after {}", function() {
        let value = calc.get();
        expect(value).to.be.equal(0);
    });

    it("should return -5 after {sub 3; sub 2}", function() {
        calc.subtract(3); calc.subtract(2); let value = calc.get();
        expect(value).to.be.equal(-5);
    });

    it("should return 4.19 after {add 5.3; sub 1.1}", function() {
        calc.add(5.3); calc.subtract(1.1); let value = calc.get();
        expect(value).to.be.equal(5.3-1.1);
    });

    it("should return NaN after {add 'hello'}", function() {
        calc.add("hello"); let value = calc.get();
        expect(value).to.be.NaN;
    });

    it("should return NaN after {sub 'hello'}", function() {
        calc.subtract("hello"); let value = calc.get();
        expect(value).to.be.NaN;
    });

    //add(10); subtract('7'); add('-2'); subtract(-1); get - > 2
    it("should return 2 after {add(10), subtract('7'), add('-2'), subtract(-1)}", function() {
        calc.add(10); calc.subtract('7'); calc.add('-2'); calc.subtract('-1'); let value = calc.get();
        expect(value).to.be.equal(2);
    });
});