Rails 3.1, RSpec: testing model validations
I have started my journey with TDD in Rails and have run into a small issue regarding tests for model validations that I can't seem to find a solution to. Let's say I have a User model,
class User < ActiveRecord::Base
validates :username, :presence => true
end
and a simple test
it "should require a username" do
User.new(:username => "").should_not be_valid
end
This correctly tests the presence validation, but what if I want to be more specific? For example, testing full_messages on the errors object..
it "should require a username" do
user = User.create(:username => "")
user.errors[:username].should ~= /can't be blank/
end
My concern about the initial attempt (using should_not be_valid) is that RSpec won't produce a descriptive error message. It simply says "expected valid? to return false, got true." However, the second test example has a minor drawback: it uses the create method instead of the new method in order to get at the errors object.
I would like my tests to be more specific about what they're testing, but at the same time not have to touch a database.
Anyone have any input?
First I would like to say you have a wicked name.
Second, CONGRATULATIONS on you endeavor into TDD with ROR I promise once you get going you will not look back.
The simplest quick and dirty solution will be to generate a new valid model before each of your tests like this:
before(:each) do
@user = User.new
@user.username = "a valid username"
end
BUT what I suggest is you set up factories for all your models that will generate a valid model for you automatically and then you can muddle with individual attributes and see if your validation. I like to use FactoryGirl for this:
Basically once you get set up your test would look something like this:
it "should have valid factory" do
FactoryGirl.build(:user).should be_valid
end
it "should require a username" do
FactoryGirl.build(:user, :username => "").should_not be_valid
end
Oh ya and here is a good railscast that explains it all better than me:
good luck :)
UPDATE: As of version 3.0 the syntax for factory girl has changed. I have amended my sample code to reflect this.
An easier way to test model validations (and a lot more of active-record) is to use a gem like shoulda or remarkable.
They will allow to the test as follows:
describe User
it { should validate_presence_of :name }
end
尝试这个：
it "should require a username" do
user = User.create(:username => "")
user.valid?
user.errors.should have_key(:username)
end
上一篇: 红宝石