test_for_signing_up_user.rb

# frozen_string_literal: true

require 'test_helper'

class SignUpTest < ActionDispatch::IntegrationTest
  test 'can user sign up' do
    get users_path

    assert_response :success

    assert_difference 'User.count' do
      post users_path,
           params: { user: { email: 'am@example.com', password: 'password' } }
    end

    assert_redirected_to root_path

    assert_select 'h1', 'Welcome'
  end

  test "user can't sign up without email and password" do
    get users_path

    assert_response :success

    assert_no_difference 'User.count' do
      post users_path,
           params: { user: { email: 'am@example.com', password: 'password' } }
    end

    assert_response :error

    assert_select 'h2', 'error'
  end
end

# and here's the error:

# "User.count" didn't change by 1.
# Expected: 1
# Actual: 0

# Here's the user's controller:

class UsersController < ApplicationController
  before_action :set_user, only: %i[edit update show]

  before_action :require_same_user, only: %i[edit update destroy]

  before_action :require_admin, only: %i[destroy]

  def index
    @users = User.paginate(page: params[:page], per_page: 5)
  end

  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)

    if @user.save
      session[:user_id] = @user.id

      flash[:success] = "Welcome to the Alpha Blog #{@user.username}"

      redirect_to user_path(@user)
    else
      render 'new'
    end
  end

  def edit; end

  def update
    if @user.update(user_params)
      flash[:success] = 'Your account was update successfully!'

      redirect_to articles_path
    else
      render 'edit'
    end
  end

  def show
    @user_articles = @user.articles.paginate(page: params[:page], per_page: 5)
  end

  def destroy
    @user = User.find(params[:id])

    @user.destroy

    flash[:danger] = 'User and all articles created by user have been deleted.'

    redirect_to users_path
  end

  private

  def user_params
    params.require(:user).permit(:username, :email, :password)
  end

  def set_user
    @user = User.find(params[:id])
  end

  def require_same_user
    if (current_user != @user) && !current_user.admin?
      flash[:danger] = 'You can only edit your own account.'

      redirect_to root_path
    end
  end

  def require_admin
    if logged_in? && !current_user.admin?
      flash[:danger] = 'Only admin users can perform that action.'

      redirect_to root_path
    end
  end
end

# Here's the sessions controller:

class SessionsController < ApplicationController
  def new; end

  def create
    user = User.find_by(email: params[:session][:email].downcase)

    if user&.authenticate(params[:session][:password])
      session[:user_id] = user.id

      flash[:success] = 'You have successfully logged in.'

      redirect_to user_path(user)
    else
      flash.now[:danger] =
        'There was something wrong with your login information.'

      render 'new'
    end
  end

  def destroy
    session[:user_id] = nil

    flash[:success] = 'You have logged out!'

    redirect_to root_path
  end
end