I am currently getting closely acquainted with Behavior-Driven Development. Could someone tell me how I am doing with the Fizzbuzz program below? I am interested in both improving the Javascipt code and the BDD prowess. Any help is appreciated.fizzbuzz.jsmodule.exports = function(word, value){       function sortNumber(a,b) {        return a - b;    }    numbers = function(divisor, max){        var result = []        for(i=1;i<=max;i++){            if ((i % divisor) === 0)                result.push(i)        }        return result    }    if (value <= 0)        return ['error','nonpositive']    else {        switch(word) {            case 'fizz':                return numbers(3, value)            case 'buzz':                return numbers(5,value)            case 'fizzbuzz':                return numbers(3,value).concat(numbers(5,value)).filter(function(elem,index,self){                        return index == self.indexOf(elem)                    }).sort(sortNumber)            default:                return ['error','wrongword']        }    }}; test/fizzbuzz-spec.js:var chai = require('chai');    expect = chai.expect,    fizzbuzz = require('../lib/fizzbuzz');describe('A fizzbuzz', function(){    describe('will return an error for invalid words: ', function(){        it('like fuss', function(){            expect(fizzbuzz('fuss', 10)).to.be.deep.equal(['error','wrongword']);        });        it('like biss', function(){            expect(fizzbuzz('biss', 10)).to.be.deep.equal(['error','wrongword']);        });    });    describe('will return an error when non-positive integer is passed', function(){        it('like 0', function(){            expect(fizzbuzz('buzz', 0)).to.be.deep.equal(['error','nonpositive']);        })        it('like -2', function(){            expect(fizzbuzz('buzz', -2)).to.be.deep.equal(['error','nonpositive']);        })    })    describe('will return valid non-error input when positive integers and valid words are passed', function(){        it('like fizz and 20', function(){            expect(fizzbuzz('fizz', 20)).not.to.contain('error');        })        it('like buzz and 20', function(){            expect(fizzbuzz('buzz', 20)).not.to.contain('error');        })        it('like fizzbuzz and 20', function(){            expect(fizzbuzz('fizzbuzz', 20)).not.to.contain('error');        })          })    describe('will return valid results for some basic valid test cases', function(){        it('like fizz and 10', function(){            expect(fizzbuzz('fizz', 10)).to.be.deep.equal([3,6,9]);        })        it('like fizz and 20', function(){            expect(fizzbuzz('fizz', 20)).to.be.deep.equal([3,6,9,12,15,18]);        })        it('like buzz and 10', function(){            expect(fizzbuzz('buzz', 10)).to.be.deep.equal([5,10]);        })        it('like buzz and 25', function(){            expect(fizzbuzz('buzz', 25)).to.be.deep.equal([5,10,15,20,25]);        })        it('like fizzbuzz and 10', function(){            expect(fizzbuzz('fizzbuzz', 10)).to.be.deep.equal([3,5,6,9,10]);        })        it('like fizzbuzz and 25', function(){            expect(fizzbuzz('fizzbuzz', 25)).to.be.deep.equal([3,5,6,9,10,12,15,18,20,21,24,25]);        })        it('like fizz and 2', function(){            expect(fizzbuzz('fizz', 2)).to.be.deep.equal([]);        })        it('like buzz and 4', function(){            expect(fizzbuzz('buzz', 4)).to.be.deep.equal([]);        })    })});
Javascript FizzBuzz and Behavior-Driven Development Using Mocha and Chai
javascript;unit testing;fizzbuzz;bdd