Rspec Test Won't Pass using assigns()
require 'spec_helper'

describe UsersController do
  render_views
  .
  .
  .
  describe "success" do

   before(:each) do
    @attr = { :name => "New User", :email => "user@example.com",
              :password => "foobar", :password_confirmation => "foobar" }
  end

  it "should create a user" do
    lambda do
      post :create, :user => @attr
    end.should change(User, :count).by(1)
  end

  it "should redirect to the user show page" do
    post :create, :user => @attr
    response.should redirect_to(user_path(assigns(:user)))
   end
  end
 end
end

Failures:

1) UsersController POST 'create' success should redirect to the user show page
 Failure/Error: response.should redirect_to(user_path(user))
 ActionController::RoutingError:
   No route matches {:action=>"show", :controller=>"users"}
 # ./spec/controllers/users_controller_spec.rb:95:in `block (4 levels) in <top (required)>'

def create
  @title = "Sign up"
  @user = User.new(params[:user])
  if @user.save
    redirect_to @user, :notice => "Signed Up!"
  else
    @title = "Sign up"
    render "new"
  end
end

it "should redirect to the user show page" do
  post :create, :user => @attr
  user = assigns(:user)
  user.should_not be_blank
  puts "user errors are: #{user.errors.full_messages.inspect}" unless user.is_valid?
  user.should be_valid
  response.should redirect_to(user_path(user))
end

1) UsersController POST 'create' success should redirect to the user show page
     Failure/Error: user.should_not be_blank
       expected blank? to return false, got true
     # ./spec/controllers/users_controller_spec.rb:94:in `block (4 levels) in <top (required)>'

response.should redirect_to(user_path(:user))

response.should redirect_to(user_path(user))

it "should redirect to the user show page" do
  post :create, :user => @attr
  user = assigns(:user)
  user.should_not be_blank
  puts "user errors are: #{user.errors.full_messages.inspect}" unless user.is_valid?
  user.should be_valid
  response.should redirect_to(user_path(user))
end

it "should assign an @user variable" do
  post :create, :user => @attr
  assigns[:user].should_not be_nil
  assigns[:user].should be_kind_of(User)
end

it "should redirect to the user show page" do
    @user = Factory(:user)
    post :create, :user => @attr
    user = assigns(:user)
    response.should redirect_to(user_path(@user))
  end

it "should redirect to the user show page" do
    post :create, :user => @attr
    user = assigns(:user)
    response.should redirect_to(user_path(user))
  end