text: const expect = require('chai').expect;
  
  const Triangle = require('../lib/triangle');
  
  describe('Triangle', () => {
    describe('Calculation of circumference', () => {
      it('calculateCircumference() should return 3.414213562373095 if called with parameters 1, 1', () => {
        expect(Triangle.calculateCircumference(1, 1)).to.equal(3.414213562373095);
      });
  
      it('calculateCircumference() should return 6.82842712474619 if called with parameters 2, 2', () => {
        expect(Triangle.calculateCircumference(2, 2)).to.equal(6.82842712474619);
      });
  
      it('calculateCircumference() should throw \'Parameter missing or not a number!\' if called with one parameter', () => {
        expect(() => Triangle.calculateCircumference(1)).to.throw('Parameter missing or not a number!');
      });
  
      it('calculateCircumference() should throw \'Parameter missing or not a number!\' if called with non-number parameter', () => {
        expect(() => Triangle.calculateCircumference('a', 1)).to.throw('Parameter missing or not a number!');
      });
    });
  
    describe('Calculation of area', () => {
      it('calculateArea() should return 0.5 if called with parameters 1, 1', () => {
        expect(Triangle.calculateArea(1, 1)).to.equal(0.5);
      });
  
      it('calculateArea() should return 3 if called with parameters 2, 2', () => {
        expect(Triangle.calculateArea(2, 2)).to.equal(2);
      });
  
      it('calculateArea() should throw \'Parameter missing or not a number!\' if called with one parameter', () => {
        expect(() => Triangle.calculateArea(1)).to.throw('Parameter missing or not a number!');
      });
  
      it('calculateArea() should throw \'Parameter missing or not a number!\' if called with non-number parameter', () => {
        expect(() => Triangle.calculateArea('a', 1)).to.throw('Parameter missing or not a number!');
      });
    });
  });
  