Testing to see if function call works without a callback.

test.js

var assert = require('assert');

function maybeCallback(callback) {
  setTimeout(function() {
    callback();
  }, 5000);
};

describe('maybeCallback', function() {
  it('should execute without a callback function', function(done) {
    this.timeout(10000);
    var error = null;

    try {
      maybeCallback();
    } catch (ex) {
      error = ex;
    }

    setTimeout(function() {
      if (error) {
        assert(false);
      }
      done();
    }, 5000);
  });
});