claude-rails-dev

Based on your request, I've generated the following Rails code for your new user authentication feature. Here's the implementation guide:

1. First, create the User model with the following code:
```ruby
class CreateUsers < ActiveRecord::Migration[6.1]
  def change
    create_table :users do |t|
      t.string :email, null: false
      t.string :password_digest, null: false
      t.timestamps
    end
  end
end
```

2. Generate the User model with:
```ruby
class User < ApplicationRecord
  has_secure_password
  validates :email, presence: true, uniqueness: true
end
```

3. Create the SessionsController for handling logins:
```ruby
class SessionsController < ApplicationController
  def new
  end

  def create
    user = User.find_by(email: params[:email])
    if user&.authenticate(params[:password])
      session[:user_id] = user.id
      redirect_to root_path, notice: 'Logged in successfully'
    else
      flash.now[:alert] = 'Invalid email or password'
      render :new
    end
  end

  def destroy
    session[:user_id] = nil
    redirect_to root_path, notice: 'Logged out successfully'
  end
end
```

4. Create the corresponding views in app/views/sessions:

- new.html.erb:
```erb
<h1>Log In</h1>
<%= form_with url: sessions_path do |form| %>
  <div>
    <%= form.label :email %>
    <%= form.email_field :email %>
  </div>
  <div>
    <%= form.label :password %>
    <%= form.password_field :password %>
  </div>
  <div>
    <%= form.submit 'Log In' %>
  </div>
<% end %>
```

- _form.html.erb (partial for login form):
```erb
<%= form_with model: @user, url: sessions_path do |form| %>
  <div>
    <%= form.label :email %>
    <%= form.email_field :email %>
  </div>
  <div>
    <%= form.label :password %>
    <%= form.password_field :password %>
  </div>
  <div>
    <%= form.submit 'Log In' %>
  </div>
<% end %>
```

5. Add authentication routes to config/routes.rb:
```ruby
resources :sessions, only: [:new, :create, :destroy]
```

6. Create a UsersController for registration:
```ruby
class UsersController < ApplicationController
  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)
    if @user.save
      redirect_to root_path, notice: 'Account created successfully'
    else
      render :new
    end
  end

  private
  def user_params
    params.require(:user).permit(:email, :password, :password_confirmation)
  end
end
```

7. Create the registration views in app/views/users:

- new.html.erb:
```erb
<h1>Sign Up</h1>
<%= form_with model: @user, url: users_path do |form| %>
  <div>
    <%= form.label :email %>
    <%= form.email_field :email %>
  end
  <div>
    <%= form.label :password %>
    <%= form.password_field :password %>
  </div>
  <div>
    <%= form.label :password_confirmation %>
    <%= form.password_field :password_confirmation %>
  </div>
  <div>
    <%= form.submit 'Sign Up' %>
  </div>
<% end %>
```

8. Add registration routes to config/routes.rb:
```ruby
resources :users, only: [:new, :create]
```

9. Add authentication helpers to ApplicationController:
```ruby
class ApplicationController < ActionController::Base
  helper_method :current_user, :logged_in?

  private
  def current_user
    @current_user ||= User.find_by(id: session[:user_id]) if session[:user_id]
  end

  def logged_in?
    !!current_user
  end
end
```

10. Add a navigation partial to app/views/layouts/_navigation.html.erb:
```erb
<% if logged_in? %>
  <%= link_to 'Log Out', sessions_path, method: :delete %>
<% else %>
  <%= link_to 'Log In', new_session_path %>
  <%= link_to 'Sign Up', new_user_path %>
<% end %>
```

To implement this feature, run the following commands in your terminal:

1. `rails generate migration CreateUsers email:string password_digest:string`
2. `rails db:migrate`
3. `rails generate controller Sessions new create destroy`
4. `rails generate controller Users new create`

After running these commands, copy the generated code into the appropriate files and you'll have a fully functional user authentication system in your Rails application.