NoMethodError: undefined method 'user' for nil:NilClass - ruby-on-rails

Question

I'm working through the book APIs on Rails and am super stuck in chapter 5 trying to test the sessions controller. I'm getting the following error and can't seem to track it down. Is there a good method for hunting down these kinds of error? And what am I missing?
1) Api::V1::SessionsController POST #create when the credentials are correct returns the user record corresponding to the given credentials
Failure/Error: post :create, { session: credentials }
NoMethodError:
undefined method `user' for nil:NilClass
App is in Rails 4.0.2, Ruby 2.2.1
Here is my test:
require 'spec_helper'
describe Api::V1::SessionsController do
describe "POST #create" do
before(:each) do
#user = FactoryGirl.create :user
end
context "when the credentials are correct" do
puts #user
before(:each) do
credentials = { email: #user.email, password: "12345678" }
post :create, { session: credentials }
end
it "returns the user record corresponding to the given credentials" do
#user.reload
expect(json_response[:auth_token]).to eql #user.auth_token
end
it { should respond_with 200 }
end
end
end
Here is the Sessions Controller:
class Api::V1::SessionsController < ApplicationController
respond_to :json
def create
user_password = params[:session][:password]
user_email = params[:session][:email]
user = user_email.present? && User.find_by(email: user_email)
if user.valid_password? user_password
sign_in user, store: false
user.generate_authentication_token!
user.save
render json: user, status: 200, location: [:api, user]
else
render json: { errors: "Invalid email or password" }, status: 422
end
end
end
The User Controller:
class Api::V1::UsersController < ApplicationController
respond_to :json
def show
respond_with User.find(params[:id])
end
def create
user = User.new(user_params)
if user.save
render json: user, status: 201, location: [:api, user]
else
render json: { errors: user.errors }, status: 422
end
end
def update
user = User.find(params[:id])
if user.update(user_params)
render json: user, status: 200, location: [:api, user]
else
render json: { errors: user.errors }, status: 422
end
end
def destroy
user = User.find(params[:id])
user.destroy
head 204
end
private
def user_params
params.require(:user).permit(:email, :password, :password_confirmation)
end
end
The routes.rb:
require 'api_constraints'
MarketPlaceApi::Application.routes.draw do
mount SabisuRails::Engine => "/sabisu_rails"
devise_for :users
# Api definition
namespace :api, defaults: { format: :json }, constraints: { subdomain: 'api' }, path: '/' do
scope module: :v1, constraints: ApiConstraints.new(version: 1, default: true) do
resources :users, :only => [:show, :create, :update, :destroy]
resources :sessions, :only => [:create, :destroy]
end
end
end
And the user model:
class User < ActiveRecord::Base
validates :auth_token, uniqueness: true
# Include default devise modules. Others available are:
# :confirmable, :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
before_create :generate_authentication_token!
def generate_authentication_token!
begin
self.auth_token = Devise.friendly_token
end while self.class.exists?(auth_token: auth_token)
end
end

Answer 1

Have you added devise_helper to spec/rails_helper.rb ?
RSpec.configure do |config|
...
config.include Devise::TestHelpers, type: :controller
...
end

Answer 2

Change
if user.valid_password? user_password
to:
if user and valid_password? user_password
or:
if user && valid_password?(user_password)
in your sessions_controller.rb file.

Answer 3

Do you have a User factory?
FactoryGirl.define do
factory :user do
username user
email user#user.com
password '12345678'
password_confirmation { '12345678' }
end
end
You need to have it defined so that FactoryGirl can create a user