07. Add / Subtract

const { expect } = require("chai");

const { createCalculator } = require("./addSubtract");
const mainFunc = createCalculator();

describe("addSubtract", () => {
  it("inner sum value is not acsecable outside the mainFunction", () => {
    expect(mainFunc.value).to.be.undefined;
  });
  it("inner function getreturns", () => {
    expect(mainFunc.get()).to.equal(0);
  });
  it("inner function add works with intigers", () => {
    mainFunc.add(1);
    expect(mainFunc.get()).to.equal(1);
    mainFunc.add(1);
    expect(mainFunc.get()).to.equal(2);
  });
  it("inner function subtract works with intigers", () => {
    mainFunc.subtract(1);
    expect(mainFunc.get()).to.equal(1);
    mainFunc.subtract(1);
    expect(mainFunc.get()).to.equal(0);
  });
  it("inner function add works with strings containing numbers", () => {
    mainFunc.add("1");
    expect(mainFunc.get()).to.equal(1);
    mainFunc.add("1");
    expect(mainFunc.get()).to.equal(2);
  });
  it("inner function subtract works with strings containing numbers", () => {
    mainFunc.subtract("1");
    expect(mainFunc.get()).to.equal(1);
    mainFunc.subtract("1");
    expect(mainFunc.get()).to.equal(0);
  });
  it("inner function add works with floating point numbers", () => {
    mainFunc.add(1.1);
    expect(mainFunc.get()).to.equal(1.1);
  });
  it("inner function subtract works with floating point numbers", () => {
    mainFunc.subtract(1.1);
    expect(mainFunc.get()).to.equal(0);
  });
  it("inner function add works with negative numbers", () => {
    mainFunc.add(-1);
    expect(mainFunc.get()).to.equal(-1);
    mainFunc.add(-1);
    expect(mainFunc.get()).to.equal(-2);
  });
  it("inner function subtract works with negative numbers", () => {
    mainFunc.subtract(-2);
    expect(mainFunc.get()).to.equal(0);
  });
  it("inner functions add and subtract return undefined if no argument", () => {
    expect(mainFunc.add()).to.be.undefined;
    expect(mainFunc.subtract()).to.be.undefined;
  });

  it("inner functions add and subtrack return undefined if argument not a number", () => {
    expect(mainFunc.add("a")).to.be.undefined;
    expect(mainFunc.subtract("b")).to.be.undefined;
  });
  it("inner function get return NaN if add and subtract called with no arg or args are not in type", () => {
    mainFunc.add("a");
    mainFunc.subtract();
    expect(mainFunc.get()).to.be.NaN;
  });
});