javascript - mochajs referenceerror when testing function not in test file -

i have mochajs test file , javascript code file in setup below:

/js/module/codefile.js /js/test/testfile.js 

the codefile.js contains javascript functions eg:

function addnumbers(a, b){     return a+b; } 

the testfile.js calls functions in codefile test them:

describe("add numbers test", function() {     it("checks valid result", function() {         var = 2;         var b = 1;         var result = addnumbers(a, b);         expect(result).to.equal(3);     }); }); 

from command line cd js folder (parent of test , module directories) run mocha , following error: referenceerror: addnumbers not defined @ context <anonymous> (test/testfile.js).

i can't see how defined how can mocha know function comming from? (nb using client side js can't use import, , havent see way specificy (in mocha or karma or js in general) functions defined in python or java). ideas on how can simple unit tests running in mocha?

i tried getting mocha run in webstorm gave after similar errors.

well, mocha command nodejs program. means can use nodejs's module system load function.

function addnumbers(a, b){     return a+b; }  module.exports = addnumbers; 

and in test file have

var addnumbers = require('../module/codefile.js');  describe("add numbers test", function() {     it("checks valid result", function() {         var = 2;         var b = 1;         var result = addnumbers(a, b);         expect(result).toequal(3);     }); }); 

however, said using code on front-end. in case check if module object exists. if exists means file required mocha unit testing.

    function addnumbers(a, b){         return a+b;     }      if (module && module.exports) {        module.exports = addnumbers;     } 

if want rid of nasty if's, can bundle modules using browserify. browserify helps code on front-end using nodejs's module system. code remain same.