node.js - Supertest/mocha done parameter passed within tests -

below code wrote mocha, chai , supertest. have question regards segment of code below works, focus on token.

describe('authenticated usertest', function () {     var token;      before(function loginauth(done) {         request(app)             .post("/login/local")             .send("username=testname")             .send("password=qwe123qwe")             .expect(function (res) {                 should.exist(res.body.token);                 token = res.body.token;             })             .end(done);     });      it('should give me defined token', function(done) {         console.log("token " + token);         done();     }); }); 

apparently, token defined , here. however, when remove done function follows:

describe('authenticated usertest', function () {     var token;      before(function loginauth() { //done removed here         request(app)             .post("/login/local")             .send("username=testname")             .send("password=qwe123qwe")             .expect(function (res) {                 should.exist(res.body.token);                 token = res.body.token;             })             .end(); //done removed here     });      it('should give me defined token', function(done) {         console.log("token " + token);         done();     }); }); 

token becomes undefined. understand, done function passed down before hook various tests thereafter starts it(...) inbuilt source code.

thus, want clarify particular question (if done passed across tests; if done accepts err parameter) , why did token become undefined after removing done parameter?

thank you.

token didn't become undefined... @ point try use it, still undefined. token has not yet been set because mocha not know working async test.

see https://justinbellamy.com/testing-async-code-with-mocha/