How do I test the assignment of an instance variable in the new action of my controller with rspec?

rspec, ruby, ruby-on-rails, ruby-on-rails-3, testing

Solution

You should probably change your test to something like this:

describe UsersController do

  describe "GET 'new'" do
    it "assigns a new User to @user" do
      get :new
      assigns(:user).should be_new_record
      assigns(:user).kind_of?(User).should be_true
    end
    it "renders the :new template"   end

end

And you will have the same effect. If two objects aren't saved, they don't have primary keys to Rails is going to use object_id equality to compare them, that's why they're not ==.

Problem

I am fairly new to testing and have a UsersController that I want to test. I am starting with the new action and so far have the following; ``` require 'spec_helper' describe UsersController do describe "GET 'new'" do it "assigns a new User to @user" do user = User.new get :new assigns(:user).should eq(user) end it "renders the :new template" end end ``` My UsersController so far looks like this ``` class UsersController < ApplicationController def new @user = User.new end end ``` I expected my first test to work but when I run it I get the following; ``` Failures: 1) UsersController GET 'new' assigns a new User to @user Failure/Error: assigns(:user).should eq(user) expected: #<User id: nil, email: nil, username: nil, password_digest: nil, created_at: nil, updated_at: nil> got: #<User id: nil, email: nil, username: nil, password_digest: nil, created_at: nil, updated_at: nil> (compared using ==) Diff:#<User:0x007fe4bbfceed0>.==(#<User:0x007fe4bce5c290>) returned false even though the diff between #<User:0x007fe4bbfceed0> and #<User:0x007fe4bce5c290> is empty. Check the implementation of #<User:0x007fe4bbfceed0>.==. # ./spec/controllers/users_controller_spec.rb:9:in `block (3 levels) in <top (required)>' ``` Playing around in the console reveals the following; ``` irb(main):001:0> a = User.new => #<User id: nil, email: nil, username: nil, password_digest: nil, created_at: nil, updated_at: nil> irb(main):002:0> b = User.new => #<User id: nil, email: nil, username: nil, password_digest: nil, created_at: nil, updated_at: nil> irb(main):003:0> a == b => false ``` So now I'm curious as to why 2 empty ActiveRecord objects are not equal (after all, `Array.new == Array.new` returns true), and what I have to do to make my test pass.

Original source