Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

JavaScript JavaScript Unit Testing Improving Our Tests Catching an Error

Vitaly Kashubin
Vitaly Kashubin
8,449 Points

Can't find a fault! Could you please help me?

I don`t understand where am i wrong?

subtraction_spec.js
var expect = require('chai').expect

describe('subtraction', function () {
  var subtraction = require('../WHEREVER')  
  it('only works with numbers', function () {
    let handel = function (){subtraction("la",12);};
    expect(handel).to.throw(Error);
    expect(handel).to.throw('subtraction only works with numbers!');
  })
})
subtraction.js
function subtraction (number1, number2) {
  if (typeof number1 !== 'number' || typeof number2 !== 'number') {
    throw Error('subtraction only works with numbers!')
  }
  return number1 - number2
}

1 Answer

Not sure why but I changed let to var and it passed