Test

const expect = require('chai').expect;

const calc = require('../../app/calc');

describe('Calc method', () => {

  const testData = {
    negative: [
      { a: true },
      { a: 'foo', b: 2 },
      { a: 1, b: { name: 'John' } },
      { a: null, b: 'bar' }
    ],
    sumPositive: [
      { a: -1, b: 1, sum: 0 },
      { a: 10, b: 101, sum: 111 },
      { a: 11, b: -3, sum: 8 },
      { a: -42, b: 12, sum: -30 },
    ],
    multiplicationPositive: [
      { a: -1, b: 1, multiplication: -1 },
      { a: 10, b: 101, multiplication: 1010 },
      { a: 11, b: -3, multiplication: -33 },
      { a: -42, b: 12, multiplication: -504 },
    ],
  };

  testData.negative.forEach(({ a, b }) => {
    it(`should throw an error if not a number parameters a = ${a} and b = ${b} passed`, () => {
      const addWithError = () => calc.add(a, b);
      expect(addWithError).to.throw(TypeError);
    });
  });

  testData.sumPositive.forEach(({ a, b, sum }) => {
    it(`should return valid value ${sum} for sum of numbers ${a} and ${b}`, () => {
      expect(calc.add(a, b)).to.equal(sum);
    });
  });

  testData.negative.forEach(({ a, b }) => {
    it(`should throw an error if not a number parameters a = ${a} and b = ${b} passed`, () => {
      const multiplyWithError = () => calc.multiply(a, b);
      expect(multiplyWithError).to.throw(TypeError);
    });
  });

  testData.multiplicationPositive.forEach(({ a, b, multiplication }) => {
    it(`should return valid value ${multiplication} for multiplication of numbers ${a} and ${b}`, () => {
      expect(calc.multiply(a, b)).to.equal(multiplication);
    });
  });
});