Don't ignore Node error parameters. Silent errors cause lots of lost time.

gistfile1.txt

// I was performing a simple update of a MongoDB object
// .update() doesn't return the data after execution
// Because I wasn't concerned with the return value from .update(),
// I foolishly forgot to add callback parameters to account for a possible error being returned.
// The result was a silent failure that was breaking my tests causing much frustration.

// bad
function savePerson(newPersonData, done) {
  Person.findByEmail({ email: newPersonData.email ), function(err, person) {
    if (err) { done(err); }
    
    _.merge(person, newPersonData);
    
    // silently fails because update() does not work for objects with an _id
    person.update(function() {
      done(null, person);
    });
  }
}

// good
function savePerson(newPersonData, done) {
  Person.findByEmail({ email: newPersonData.email ), function(err, person) {
    if (err) { done(err); }
    
    _.merge(person, newPersonData);
    
    // correctly passes err to parent function
    person.update(function(err) {
      if (err) { done(err); }
      done(null, person);
    });
  }
}