Why won't my supertest calls chain?

Question

It never hits the inner call, so done() isn't being called and my Mocha test is timing out. Why is this?

testUsers.forEach(function(loggedInUser) {
  var describeStr;
  if (loggedInUser && loggedInUser.username === 'a') {
    describeStr = 'Tangos API (role: user)';
  }
  else if (loggedInUser && loggedInUser.username === 'admin') {
    describeStr = 'Tangos API (role: admin)';
  }
  else {
    describeStr = 'Tangos API (not logged in)';
  }

  describe(describeStr, function() {
    var id;

    beforeEach(function(done) {
      if (!loggedInUser) {
        return done();
      }

      agent
        .post('/users')
        .send(loggedInUser)
        .end(function(err, res) {
          console.log('err: ', err); // null
          console.log('res.text: ', res.text); // correct
          agent
            .post('/tangos')
            .send(testTango)
            .end(function(err, result) {
              console.log('inner'); // never hits here
              if (err) {
                return done(err);
              }
              return done(); // never hits here, so mocha tests time out
            })
          ;
        })
      ;
    });

Using async doesn't work either:

async.series([
  function() {
    agent
      .post('/users')
      .send(loggedInUser)
      .end(function(err, res) {
        console.log('err: ', err); // null
        console.log('res.text: ', res.text); // correct
      })
    ;
  }, function() {
    agent
      .post('/tangos')
      .send(testTango)
      .end(function(err, result) {
        console.log('inner'); // never hits here
      })
    ;
  }
], done);

Answer 1

I see 2 possible issues here. First of all, your async series is missing the callbacks that are needed in each function.

async.series([
  function(callback) {
    agent
      .post('/users')
      .send(loggedInUser)
      .end(function(err, res) {
        console.log('err: ', err); // null
        console.log('res.text: ', res.text); // correct
        callback(); // Need to call the callback here.
      })
    ;
  }, function(callback) {
    agent
      .post('/tangos')
      .send(testTango)
      .end(function(err, result) {
        console.log('inner'); // never hits here
        callback(); // Need to call callback here too.
      })
    ;
  }
], done);

I ran this exact test with my own endpoint it worked fine.

The first code snippet looks okay and works fine for me. I would venture to say you are timing out before it gets the chance to finish. By default, the timeout is 2000ms. It would make sense that 2 API calls don't finish in 2 seconds. To increase the timeout, simply put

this.timeout(5000);

in the describe block to increase the timeout value.