Rails Tutorial: RSpec test decoupling

问题:

I'm trying to do Exercise 2 of Chapter 8.5 in Michael Hartl's Ruby on Rails Tutorial. The exercise is as follows:

Following the example in Section 8.3.3, go through the user and authentication request specs (i.e., the files currently in the spec/requests directory) and define utility functions in spec/support/utilities.rb to decouple the tests from the implementation. Extra credit: Organize the support code into separate files and modules, and get everything to work by including the modules properly in the spec helper file.

Example 8.3.3: utilities.rb

include ApplicationHelper

def valid_signin(user)
  fill_in "Email",    with: user.email
  fill_in "Password", with: user.password
  click_button "Sign in"
end

RSpec::Matchers.define :have_error_message do |message|
  match do |page|
    page.should have_selector('div.alert.alert-error', text: message)
  end
end

The defined valid_signin(user) function is used in the following block of authentication_pages_spec.rb and works fine.

describe "with valid information" do
    let(:user){FactoryGirl.create(:user)}
    before { valid_signin(user) }

    it { should have_selector('title', text: user.name) }
    it { should have_link('Profile', href: user_path(user)) }
    it { should have_link('Sign out', href: signout_path) }
    it { should_not have_link('Sign in', href: signin_path) }

    describe "followed by signout" do
        before { click_link "Sign out" }
        it { should have_link('Sign in') }
    end
end

So with this example I set about to create my own named valid_signup(user):

def valid_signup(user)
    fill_in "Name",         with: user.name
    fill_in "Email",        with: user.email
    fill_in "Password",     with: user.password
    fill_in "Confirmation",         with: user.password_confirmation
end

I'm using this block in user_pages_spec.rb like this:

describe "with valid information" do
  let(:user){FactoryGirl.create(:user)}
  before { valid_signup(user) }

  it "should create a user" do
    expect { click_button submit }.to change(User, :count).by(1)
  end

  describe "after saving the user" do
    before { click_button submit }
    let(:user) { User.find_by_email(user.email) }

    it { should have_selector('title', text: user.name) }
    it { should have_selector('div.alert.alert-success', text: 'Welcome') }
    it { should have_link('Sign out') }
  end
end

It doesn't work. Spork/Guard reports these errors:

Failures:

  1) UserPages signup with valid information should create a user
     Failure/Error: expect { click_button submit }.to change(User, :count).by(1)
       count should have been changed by 1, but was changed by 0
     # ./spec/requests/user_pages_spec.rb:46:in `block (4 levels) in '

  2) UserPages signup with valid information after saving the user 
     Failure/Error: before { valid_signup(user) }
     NoMethodError:
       undefined method `name' for nil:NilClass
     # ./spec/support/utilities.rb:10:in `valid_signup'
     # ./spec/requests/user_pages_spec.rb:43:in `block (4 levels) in '

  3) UserPages signup with valid information after saving the user 
     Failure/Error: before { valid_signup(user) }
     NoMethodError:
       undefined method `name' for nil:NilClass
     # ./spec/support/utilities.rb:10:in `valid_signup'
     # ./spec/requests/user_pages_spec.rb:43:in `block (4 levels) in '

  4) UserPages signup with valid information after saving the user 
     Failure/Error: before { valid_signup(user) }
     NoMethodError:
       undefined method `name' for nil:NilClass
     # ./spec/support/utilities.rb:10:in `valid_signup'
     # ./spec/requests/user_pages_spec.rb:43:in `block (4 levels) in '

The errors seem to suggest the user.name in my valid_signup(user) function in utilities.rb isn't defined, but I don't see any reason why. I've restarted Guard several times, and did a rake db:test:prepare to make sure the testing db (using postgresql) was in order.

Here's my factories.rb for completeness:

FactoryGirl.define do
    factory :user do
        name    "Example User"
        email   "[e-mail]"
        password    "foobar"
        password_confirmation   "foobar"
    end
end

Before I continue to try and decouple more of the testing suite I'd very much like to solve this error and, more importantly, understand the reason for it.

EDIT

I've tried your tips, and edited the function in user_pages_spec.rb as follows:

describe "with valid information" do
      before { valid_signup(user) }

      it "should create a user" do
        expect { click_button submit }.to change(User, :count).by(1)
      end

      describe "after saving the user" do
        before { click_button submit }
        let(:user) { User.find_by_email('[e-mail]') }

        it { should have_selector('title', text: user.name) }
        it { should have_selector('div.alert.alert-success', text: 'Welcome') }
        it { should have_link('Sign out') }
      end
    end

Since I removed let(:user){FactoryGirl.create(:user)} from the function I guessed there was no longer a user created in the function so I needed to define valid_signup(user) as such as the user variable for valid_signup was no longer being filled by FactoryGirl:

def valid_signup(user)
    fill_in "Name",     with: "Example User"
    fill_in "Email",    with: "[e-mail]"
    fill_in "Password", with: "foobar"
    fill_in "Confirmation", with: "foobar"
end

This didn't work and gave me the following errors:

Failures:


1) UserPages signup with valid information should create a user
     Failure/Error: before { valid_signup(user) }
     NameError:
       undefined local variable or method user' for #<RSpec::Core::ExampleGroup::Nested_5::Nested_3::Nested_2:0x007fdafc5088c0>
     # ./spec/requests/user_pages_spec.rb:42:inblock (4 levels) in '

2) UserPages signup with valid information after saving the user 
     Failure/Error: it { should have_selector('title', text: user.name) }
     NoMethodError:
       undefined method name' for nil:NilClass
     # ./spec/requests/user_pages_spec.rb:52:inblock (5 levels) in '

I also tried running the test with valid_signup(user) the way I used to have it before (with user.name, user.email, user.password, user.password_confirmation, which didn't work either, with errors:

Failures:

  1) UserPages signup with valid information should create a user
     Failure/Error: before { valid_signup(user) }
     NameError:
       undefined local variable or method `user' for #
     # ./spec/requests/user_pages_spec.rb:42:in `block (4 levels) in '

  2) UserPages signup with valid information after saving the user 
     Failure/Error: it { should have_selector('title', text: user.name) }
     NoMethodError:
       undefined method `name' for nil:NilClass
     # ./spec/requests/user_pages_spec.rb:52:in `block (5 levels) in '

Next I tried running it without passing variables in user_pages_spec.rb: before { valid_signup() } and without a variable in the function in utilities.rb:

def valid_signup()
    fill_in "Name",     with: "Example User"
    fill_in "Email",    with: "[e-mail]"
    fill_in "Password", with: "foobar"
    fill_in "Confirmation", with: "foobar"
end

This returned:

Failures:

  1) UserPages signup with valid information should create a user
     Failure/Error: before { valid_signup(user) }
     NameError:
       undefined local variable or method `user' for #
     # ./spec/requests/user_pages_spec.rb:42:in `block (4 levels) in '

  2) UserPages signup with valid information after saving the user 
     Failure/Error: it { should have_selector('title', text: user.name) }
     NoMethodError:
       undefined method `name' for nil:NilClass
     # ./spec/requests/user_pages_spec.rb:52:in `block (5 levels) in '

Still no closer to the answer. I might be overlooking something simple. No clue what though. I got what I first did wrong though: I just thought FactoryGirl was a way to create variables, and I didn't know it actually did something to my test database.

回答1:

I will try to explain what is going on in your original test (which I find easier to fix than the edited version):

describe "with valid information" do
  let(:user) {FactoryGirl.build(:user)} # FactoryGirl.create will save the instance, you should be using build instead
  before { valid_signup(user) }

  it "should create a user" do
    expect { click_button submit }.to change(User, :count).by(1)
  end

  describe "after saving the user" do
    before { click_button submit }
    # let(:user) { User.find_by_email(user.email) } # this is not needed any more 

    it { should have_selector('title', text: user.name) }
    it { should have_selector('div.alert.alert-success', text: 'Welcome') }
    it { should have_link('Sign out') }
  end
end

More info on FactoryGirl usage: https://github.com/thoughtbot/factory_girl/blob/master/GETTING_STARTED.md#using-factories

回答2:

FactoryGirl saves the user to the database, then you visit the sign_in_path with the user already on the database and fill the form for sign_in with valid_sigin(user)

let(:user){FactoryGirl.create(:user)}
before { valid_signin(user) }

When you do:

let(:user){FactoryGirl.create(:user)}
before { valid_signup(user) }

factory girl saves the user in the database, and you fill a form with an email already taken.

EDIT:

  describe "with valid information" do
  before { valid_signup(user) }

You dont have a variable user defined, since you deleted let(:user){FactoryGilr.create(:user)},and you should visit the right path, your current path is "sign_in_path" and should be "sign_up_path"

You should do something like this:

utilities.rb

def valid_sign_up(user)
  fill_in "Name",         with: user.name
  fill_in "Email",        with: user.email
  fill_in "Password",     with: user.password
  fill_in "Confirmation", with: user.password_confirmation
end

user_pages_spec.rb

describe "with valid information" do
  let(:user){User.new(name: "my name", email: "myemail@example"...)
  before do        
    visit sign_up
    valid_sign_up(user)
  end 

  it "should create a user" do
    expect { click_button submit }.to change(User, :count).by(1)
  end
end

回答3:

I had the same problem and figured out the solution: when you define valid_signup, it should take 'page' as the argument. After all, you are testing the page elements, not the user.

spec/support/utilities.rb

def valid_signup(page)
  fill_in "Name", with: "Example User"
  fill_in "Email",          with: "[e-mail]"
  fill_in "Password",       with: "foobar"
  fill_in "Confirmation",   with: "foobar"
end

spec/requests/user_pages_spec.rb

describe "with valid information" do before { valid_signup(page) }

  it "should create a user" do
    expect { click_button submit }.to change(User, :count).by(1)
  end

I hope this helps!

UPDATE I realize now that this works because of the scope of the variable 'page' (since it's the subject). To use "user" I added the line

let(:user) { FactoryGirl.create(:user) }

above

before { sign_up(user) }. This then broke a later spec where I also tried using 'user' as a variable, so I changed the name to 'editeduser'. Here's the full example:

user_pages_spec.rb

require 'spec_helper'

describe "UserPages" do

  subject { page }

...

  describe "signup page" do
    before { visit signup_path }

    let(:submit) { "Create my account" }

    it { should have_selector('h1', text: 'Sign up') }
    it { should have_selector('title', text: full_title('Sign up')) }

  describe "with invalid information" do
    it "should not create a user" do
    expect { click_button submit }.not_to change(User, :count)
  end

  describe "after submission" do
    before { click_button submit }

    it { should have_selector('title', text: 'Sign up') }
    it { should have_content('error') }
  end
end

  describe "with valid information" do
    let(:user) { FactoryGirl.create(:user) }
    before { sign_up(user) }

    it "should create a user" do
      expect { click_button submit }.to change(User, :count).by(1)
    end

    describe "after saving the user" do
      before { click_button submit }
      let(:editeduser) { User.find_by_email('[e-mail]') }

      it { should have_selector('title', text: editeduser.name) }
      it { should have_selector('div.alert.alert-success', text: 'Welcome') }
      it { should have_link('Sign out') }
    end
  end
end

Hopefully this helps someone!

回答4:

I was curious about this one as well, and found an answer that may be more in line with what Hartl was expecting (though as just learning, I'm not 100% certain the top answer isn't more elegant or not).

Since we weren't using FactoryGirl to sign up users, but instead to sign them in, I didn't want to use it in my refactoring. This is what I have in my utilities.rb:

def valid_signup
  fill_in "Name",         with: "Example User"
  fill_in "Email",        with: "[e-mail]"
  fill_in "Password",     with: "foobar"
  fill_in "Confirmation", with: "foobar"
end

and then in user_pages_spec.rb I replaced

  describe "with valid information" do
  before do
    fill_in "Name",           with: "Example User"
    fill_in "Email",          with: "[e-mail]"
    fill_in "Password",       with: "foobar"
    fill_in "Confirmation",   with: "foobar"
  end

with

  describe "with valid information" do
  before { valid_signup } 

We don't need a user to be saved to the database just to check a one time sign up, since they don't need to persist through multiple page views. Also, since we don't look up a user, we don't need a (user) argument after valid_signup method (I think I have the terminology correct. Please correct me if I do not.)