Rails model: before_save {self.password = password.strip} vs. before_save {password.strip!}

Question

I have a few lines in my User model to strip leading/tailing white-space from the User's email and password. The original code looked like this:

before_save {self.email = email.strip}
before_save {self.password = password.strip}
before_save {self.password_confirmation = password_confirmation.strip}

This passed my test:

test "password entry should ignore leading/tailing whitespace" do
 @user = User.create(name: "M", email: " [email protected]", 
  password: "  password", password_confirmation: "  password")
 assert @user.authenticate("password")
 assert_not @user.authenticate(" password")
end

Now I tried to re-factor it:

before_save {email.strip!}
before_save {password.strip!}
before_save {password_confirmation.strip!}

This works fine for my email test, but it's broken the password test above. So, the question is, how is the original version actually different from the re-factored code?

Answer 1

You cannot use password.strip! because in fact there's no such field as password - it is a setter password= that generates and stores password hash.