deviseによるログイン機能の実装

Gemfile

@@ -16,6 +16,7 @@ gem 'sqlite3', '>= 1.4'
 gem 'solid_cache'
 gem 'solid_queue'
 
+gem 'devise'
 gem 'kaminari'
 gem 'ransack'
 

Gemfile.lock

@@ -75,6 +75,7 @@ GEM
     addressable (2.8.7)
       public_suffix (>= 2.0.2, < 7.0)
     base64 (0.2.0)
+    bcrypt (3.1.20)
     benchmark (0.4.0)
     bigdecimal (3.1.9)
     bindex (0.8.1)
@@ -97,6 +98,12 @@ GEM
     debug (1.10.0)
       irb (~> 1.10)
       reline (>= 0.3.8)
+    devise (4.9.4)
+      bcrypt (~> 3.0)
+      orm_adapter (~> 0.1)
+      railties (>= 4.1.0)
+      responders
+      warden (~> 1.2.3)
     drb (2.2.1)
     erubi (1.13.1)
     et-orbi (1.2.11)
@@ -172,6 +179,7 @@ GEM
       racc (~> 1.4)
     nokogiri (1.18.3-x86_64-linux-musl)
       racc (~> 1.4)
+    orm_adapter (0.5.0)
     pp (0.6.2)
       prettyprint
     prettyprint (0.2.0)
@@ -233,6 +241,9 @@ GEM
     regexp_parser (2.10.0)
     reline (0.6.0)
       io-console (~> 0.5)
+    responders (3.1.1)
+      actionpack (>= 5.2)
+      railties (>= 5.2)
     rexml (3.4.1)
     rubyzip (2.4.1)
     securerandom (0.4.1)
@@ -290,6 +301,8 @@ GEM
       concurrent-ruby (~> 1.0)
     uri (1.0.2)
     useragent (0.16.11)
+    warden (1.2.9)
+      rack (>= 2.0.9)
     web-console (4.2.1)
       actionview (>= 6.0.0)
       activemodel (>= 6.0.0)
@@ -319,6 +332,7 @@ DEPENDENCIES
   bootsnap
   capybara
   debug
+  devise
   importmap-rails
   jbuilder
   kaminari

app/controllers/application_controller.rb

@@ -1,3 +1,4 @@
 class ApplicationController < ActionController::Base
   protect_from_forgery with: :exception
+  before_action :authenticate_user!
 end

app/models/user.rb

@@ -0,0 +1,6 @@
+class User < ApplicationRecord
+  # Include default devise modules. Others available are:
+  # :confirmable, :lockable, :timeoutable, :trackable and :omniauthable
+  devise :database_authenticatable, :registerable,
+         :recoverable, :rememberable, :validatable
+end

app/views/devise/registrations/new.html.erb

@@ -0,0 +1,43 @@
+<div class="min-h-screen flex items-center justify-center bg-gray-50">
+  <div class="max-w-md w-full space-y-8 p-8 bg-white rounded-lg shadow-md">
+    <div>
+      <h2 class="text-center text-3xl font-bold text-gray-900">アカウント登録</h2>
+    </div>
+
+    <%= form_for(resource, as: resource_name, url: registration_path(resource_name), html: { class: "mt-8 space-y-6" }) do |f| %>
+      <%= render "devise/shared/error_messages", resource: resource %>
+
+      <div class="space-y-4">
+        <div>
+          <%= f.label :email, class: "block text-sm font-medium text-gray-700" %>
+          <%= f.email_field :email, autofocus: true, autocomplete: "email",
+              class: "mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:outline-none focus:ring-blue-500 focus:border-blue-500" %>
+        </div>
+
+        <div>
+          <%= f.label :password, "パスワード", class: "block text-sm font-medium text-gray-700" %>
+          <% if @minimum_password_length %>
+            <em class="text-sm text-gray-500">（<%= @minimum_password_length %> 文字以上）</em>
+          <% end %>
+          <%= f.password_field :password, autocomplete: "new-password",
+              class: "mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:outline-none focus:ring-blue-500 focus:border-blue-500" %>
+        </div>
+
+        <div>
+          <%= f.label :password_confirmation, "パスワード（確認）", class: "block text-sm font-medium text-gray-700" %>
+          <%= f.password_field :password_confirmation, autocomplete: "new-password",
+              class: "mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:outline-none focus:ring-blue-500 focus:border-blue-500" %>
+        </div>
+      </div>
+
+      <div class="mt-6">
+        <%= f.submit "登録",
+            class: "w-full flex justify-center py-2 px-4 border border-transparent rounded-md shadow-sm text-sm font-medium text-white bg-blue-500 hover:bg-blue-600 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-blue-500" %>
+      </div>
+    <% end %>
+
+    <div class="mt-6 text-center text-sm">
+      <%= render "devise/shared/links" %>
+    </div>
+  </div>
+</div>

app/views/devise/sessions/new.html.erb

@@ -0,0 +1,39 @@
+<div class="min-h-screen flex items-center justify-center bg-gray-50">
+  <div class="max-w-md w-full space-y-8 p-8 bg-white rounded-lg shadow-md">
+    <div>
+      <h2 class="text-center text-3xl font-bold text-gray-900">ログイン</h2>
+    </div>
+
+    <%= form_for(resource, as: resource_name, url: session_path(resource_name), html: { class: "mt-8 space-y-6" }) do |f| %>
+      <div class="space-y-4">
+        <div>
+          <%= f.label :email, class: "block text-sm font-medium text-gray-700" %>
+          <%= f.email_field :email, autofocus: true, autocomplete: "email",
+              class: "mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:outline-none focus:ring-blue-500 focus:border-blue-500" %>
+        </div>
+
+        <div>
+          <%= f.label :password, "パスワード", class: "block text-sm font-medium text-gray-700" %>
+          <%= f.password_field :password, autocomplete: "current-password",
+              class: "mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:outline-none focus:ring-blue-500 focus:border-blue-500" %>
+        </div>
+
+        <% if devise_mapping.rememberable? %>
+          <div class="flex items-center">
+            <%= f.check_box :remember_me, class: "h-4 w-4 text-blue-600 focus:ring-blue-500 border-gray-300 rounded" %>
+            <%= f.label :remember_me, "ログイン状態を保持する", class: "ml-2 block text-sm text-gray-900" %>
+          </div>
+        <% end %>
+      </div>
+
+      <div class="mt-6">
+        <%= f.submit "ログイン",
+            class: "w-full flex justify-center py-2 px-4 border border-transparent rounded-md shadow-sm text-sm font-medium text-white bg-blue-500 hover:bg-blue-600 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-blue-500" %>
+      </div>
+    <% end %>
+
+    <div class="mt-6 text-center text-sm">
+      <%= render "devise/shared/links" %>
+    </div>
+  </div>
+</div>

app/views/layouts/application.html.erb

@@ -10,9 +10,21 @@
     <%= javascript_include_tag "application", "data-turbo-track": "reload", type: "module" %>
     <%= javascript_importmap_tags %>
   </head>
+
   <body class="bg-gray-50">
-    <div class="max-w-2xl mx-auto px-4">
-      <%= yield %>
+  <% if user_signed_in? %>
+    <div class="fixed top-4 right-4">
+      <%= button_to destroy_user_session_path,
+          method: :delete,
+          class: "bg-gray-500 hover:bg-gray-600 text-white font-bold py-2 px-4 rounded-lg transition-colors duration-200" do %>
+        退出
+      <% end %>
     </div>
-  </body>
+  <% end %>
+
+  <div class="max-w-2xl mx-auto px-4">
+    <%= yield %>
+  </div>
+</body>
+
 </html>

config/environments/development.rb

@@ -41,6 +41,8 @@ Rails.application.configure do
 
   config.action_mailer.perform_caching = false
 
+  config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }
+
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
 

config/initializers/devise.rb

@@ -0,0 +1,313 @@
+# frozen_string_literal: true
+
+# Assuming you have not yet modified this file, each configuration option below
+# is set to its default value. Note that some are commented out while others
+# are not: uncommented lines are intended to protect your configuration from
+# breaking changes in upgrades (i.e., in the event that future versions of
+# Devise change the default values for those options).
+#
+# Use this hook to configure devise mailer, warden hooks and so forth.
+# Many of these configuration options can be set straight in your model.
+Devise.setup do |config|
+  # The secret key used by Devise. Devise uses this key to generate
+  # random tokens. Changing this key will render invalid all existing
+  # confirmation, reset password and unlock tokens in the database.
+  # Devise will use the `secret_key_base` as its `secret_key`
+  # by default. You can change it below and use your own secret key.
+  # config.secret_key = '19b352cbfe09ee4c279b14be664c48cb949ffd8bd8f29d629c95f694d3668ed613d3869385760bf40224aafe320085407810882e1c6c6e48470af1706e350232'
+
+  # ==> Controller configuration
+  # Configure the parent class to the devise controllers.
+  # config.parent_controller = 'DeviseController'
+
+  # ==> Mailer Configuration
+  # Configure the e-mail address which will be shown in Devise::Mailer,
+  # note that it will be overwritten if you use your own mailer class
+  # with default "from" parameter.
+  config.mailer_sender = 'please-change-me-at-config-initializers-devise@example.com'
+
+  # Configure the class responsible to send e-mails.
+  # config.mailer = 'Devise::Mailer'
+
+  # Configure the parent class responsible to send e-mails.
+  # config.parent_mailer = 'ActionMailer::Base'
+
+  # ==> ORM configuration
+  # Load and configure the ORM. Supports :active_record (default) and
+  # :mongoid (bson_ext recommended) by default. Other ORMs may be
+  # available as additional gems.
+  require 'devise/orm/active_record'
+
+  # ==> Configuration for any authentication mechanism
+  # Configure which keys are used when authenticating a user. The default is
+  # just :email. You can configure it to use [:username, :subdomain], so for
+  # authenticating a user, both parameters are required. Remember that those
+  # parameters are used only when authenticating and not when retrieving from
+  # session. If you need permissions, you should implement that in a before filter.
+  # You can also supply a hash where the value is a boolean determining whether
+  # or not authentication should be aborted when the value is not present.
+  # config.authentication_keys = [:email]
+
+  # Configure parameters from the request object used for authentication. Each entry
+  # given should be a request method and it will automatically be passed to the
+  # find_for_authentication method and considered in your model lookup. For instance,
+  # if you set :request_keys to [:subdomain], :subdomain will be used on authentication.
+  # The same considerations mentioned for authentication_keys also apply to request_keys.
+  # config.request_keys = []
+
+  # Configure which authentication keys should be case-insensitive.
+  # These keys will be downcased upon creating or modifying a user and when used
+  # to authenticate or find a user. Default is :email.
+  config.case_insensitive_keys = [:email]
+
+  # Configure which authentication keys should have whitespace stripped.
+  # These keys will have whitespace before and after removed upon creating or
+  # modifying a user and when used to authenticate or find a user. Default is :email.
+  config.strip_whitespace_keys = [:email]
+
+  # Tell if authentication through request.params is enabled. True by default.
+  # It can be set to an array that will enable params authentication only for the
+  # given strategies, for example, `config.params_authenticatable = [:database]` will
+  # enable it only for database (email + password) authentication.
+  # config.params_authenticatable = true
+
+  # Tell if authentication through HTTP Auth is enabled. False by default.
+  # It can be set to an array that will enable http authentication only for the
+  # given strategies, for example, `config.http_authenticatable = [:database]` will
+  # enable it only for database authentication.
+  # For API-only applications to support authentication "out-of-the-box", you will likely want to
+  # enable this with :database unless you are using a custom strategy.
+  # The supported strategies are:
+  # :database      = Support basic authentication with authentication key + password
+  # config.http_authenticatable = false
+
+  # If 401 status code should be returned for AJAX requests. True by default.
+  # config.http_authenticatable_on_xhr = true
+
+  # The realm used in Http Basic Authentication. 'Application' by default.
+  # config.http_authentication_realm = 'Application'
+
+  # It will change confirmation, password recovery and other workflows
+  # to behave the same regardless if the e-mail provided was right or wrong.
+  # Does not affect registerable.
+  # config.paranoid = true
+
+  # By default Devise will store the user in session. You can skip storage for
+  # particular strategies by setting this option.
+  # Notice that if you are skipping storage for all authentication paths, you
+  # may want to disable generating routes to Devise's sessions controller by
+  # passing skip: :sessions to `devise_for` in your config/routes.rb
+  config.skip_session_storage = [:http_auth]
+
+  # By default, Devise cleans up the CSRF token on authentication to
+  # avoid CSRF token fixation attacks. This means that, when using AJAX
+  # requests for sign in and sign up, you need to get a new CSRF token
+  # from the server. You can disable this option at your own risk.
+  # config.clean_up_csrf_token_on_authentication = true
+
+  # When false, Devise will not attempt to reload routes on eager load.
+  # This can reduce the time taken to boot the app but if your application
+  # requires the Devise mappings to be loaded during boot time the application
+  # won't boot properly.
+  # config.reload_routes = true
+
+  # ==> Configuration for :database_authenticatable
+  # For bcrypt, this is the cost for hashing the password and defaults to 12. If
+  # using other algorithms, it sets how many times you want the password to be hashed.
+  # The number of stretches used for generating the hashed password are stored
+  # with the hashed password. This allows you to change the stretches without
+  # invalidating existing passwords.
+  #
+  # Limiting the stretches to just one in testing will increase the performance of
+  # your test suite dramatically. However, it is STRONGLY RECOMMENDED to not use
+  # a value less than 10 in other environments. Note that, for bcrypt (the default
+  # algorithm), the cost increases exponentially with the number of stretches (e.g.
+  # a value of 20 is already extremely slow: approx. 60 seconds for 1 calculation).
+  config.stretches = Rails.env.test? ? 1 : 12
+
+  # Set up a pepper to generate the hashed password.
+  # config.pepper = 'dddb03c7e5b540905d92833f5881f761e3183f69e50c9d956f7d1631909c3c89eb27fe2ee3d3d7c541ae33df2fd96cee893ca22e667adf608764684e46f75aaf'
+
+  # Send a notification to the original email when the user's email is changed.
+  # config.send_email_changed_notification = false
+
+  # Send a notification email when the user's password is changed.
+  # config.send_password_change_notification = false
+
+  # ==> Configuration for :confirmable
+  # A period that the user is allowed to access the website even without
+  # confirming their account. For instance, if set to 2.days, the user will be
+  # able to access the website for two days without confirming their account,
+  # access will be blocked just in the third day.
+  # You can also set it to nil, which will allow the user to access the website
+  # without confirming their account.
+  # Default is 0.days, meaning the user cannot access the website without
+  # confirming their account.
+  # config.allow_unconfirmed_access_for = 2.days
+
+  # A period that the user is allowed to confirm their account before their
+  # token becomes invalid. For example, if set to 3.days, the user can confirm
+  # their account within 3 days after the mail was sent, but on the fourth day
+  # their account can't be confirmed with the token any more.
+  # Default is nil, meaning there is no restriction on how long a user can take
+  # before confirming their account.
+  # config.confirm_within = 3.days
+
+  # If true, requires any email changes to be confirmed (exactly the same way as
+  # initial account confirmation) to be applied. Requires additional unconfirmed_email
+  # db field (see migrations). Until confirmed, new email is stored in
+  # unconfirmed_email column, and copied to email column on successful confirmation.
+  config.reconfirmable = true
+
+  # Defines which key will be used when confirming an account
+  # config.confirmation_keys = [:email]
+
+  # ==> Configuration for :rememberable
+  # The time the user will be remembered without asking for credentials again.
+  # config.remember_for = 2.weeks
+
+  # Invalidates all the remember me tokens when the user signs out.
+  config.expire_all_remember_me_on_sign_out = true
+
+  # If true, extends the user's remember period when remembered via cookie.
+  # config.extend_remember_period = false
+
+  # Options to be passed to the created cookie. For instance, you can set
+  # secure: true in order to force SSL only cookies.
+  # config.rememberable_options = {}
+
+  # ==> Configuration for :validatable
+  # Range for password length.
+  config.password_length = 6..128
+
+  # Email regex used to validate email formats. It simply asserts that
+  # one (and only one) @ exists in the given string. This is mainly
+  # to give user feedback and not to assert the e-mail validity.
+  config.email_regexp = /\A[^@\s]+@[^@\s]+\z/
+
+  # ==> Configuration for :timeoutable
+  # The time you want to timeout the user session without activity. After this
+  # time the user will be asked for credentials again. Default is 30 minutes.
+  # config.timeout_in = 30.minutes
+
+  # ==> Configuration for :lockable
+  # Defines which strategy will be used to lock an account.
+  # :failed_attempts = Locks an account after a number of failed attempts to sign in.
+  # :none            = No lock strategy. You should handle locking by yourself.
+  # config.lock_strategy = :failed_attempts
+
+  # Defines which key will be used when locking and unlocking an account
+  # config.unlock_keys = [:email]
+
+  # Defines which strategy will be used to unlock an account.
+  # :email = Sends an unlock link to the user email
+  # :time  = Re-enables login after a certain amount of time (see :unlock_in below)
+  # :both  = Enables both strategies
+  # :none  = No unlock strategy. You should handle unlocking by yourself.
+  # config.unlock_strategy = :both
+
+  # Number of authentication tries before locking an account if lock_strategy
+  # is failed attempts.
+  # config.maximum_attempts = 20
+
+  # Time interval to unlock the account if :time is enabled as unlock_strategy.
+  # config.unlock_in = 1.hour
+
+  # Warn on the last attempt before the account is locked.
+  # config.last_attempt_warning = true
+
+  # ==> Configuration for :recoverable
+  #
+  # Defines which key will be used when recovering the password for an account
+  # config.reset_password_keys = [:email]
+
+  # Time interval you can reset your password with a reset password key.
+  # Don't put a too small interval or your users won't have the time to
+  # change their passwords.
+  config.reset_password_within = 6.hours
+
+  # When set to false, does not sign a user in automatically after their password is
+  # reset. Defaults to true, so a user is signed in automatically after a reset.
+  # config.sign_in_after_reset_password = true
+
+  # ==> Configuration for :encryptable
+  # Allow you to use another hashing or encryption algorithm besides bcrypt (default).
+  # You can use :sha1, :sha512 or algorithms from others authentication tools as
+  # :clearance_sha1, :authlogic_sha512 (then you should set stretches above to 20
+  # for default behavior) and :restful_authentication_sha1 (then you should set
+  # stretches to 10, and copy REST_AUTH_SITE_KEY to pepper).
+  #
+  # Require the `devise-encryptable` gem when using anything other than bcrypt
+  # config.encryptor = :sha512
+
+  # ==> Scopes configuration
+  # Turn scoped views on. Before rendering "sessions/new", it will first check for
+  # "users/sessions/new". It's turned off by default because it's slower if you
+  # are using only default views.
+  # config.scoped_views = false
+
+  # Configure the default scope given to Warden. By default it's the first
+  # devise role declared in your routes (usually :user).
+  # config.default_scope = :user
+
+  # Set this configuration to false if you want /users/sign_out to sign out
+  # only the current scope. By default, Devise signs out all scopes.
+  # config.sign_out_all_scopes = true
+
+  # ==> Navigation configuration
+  # Lists the formats that should be treated as navigational. Formats like
+  # :html should redirect to the sign in page when the user does not have
+  # access, but formats like :xml or :json, should return 401.
+  #
+  # If you have any extra navigational formats, like :iphone or :mobile, you
+  # should add them to the navigational formats lists.
+  #
+  # The "*/*" below is required to match Internet Explorer requests.
+  # config.navigational_formats = ['*/*', :html, :turbo_stream]
+
+  # The default HTTP method used to sign out a resource. Default is :delete.
+  config.sign_out_via = :delete
+
+  # ==> OmniAuth
+  # Add a new OmniAuth provider. Check the wiki for more information on setting
+  # up on your models and hooks.
+  # config.omniauth :github, 'APP_ID', 'APP_SECRET', scope: 'user,public_repo'
+
+  # ==> Warden configuration
+  # If you want to use other strategies, that are not supported by Devise, or
+  # change the failure app, you can configure them inside the config.warden block.
+  #
+  # config.warden do |manager|
+  #   manager.intercept_401 = false
+  #   manager.default_strategies(scope: :user).unshift :some_external_strategy
+  # end
+
+  # ==> Mountable engine configurations
+  # When using Devise inside an engine, let's call it `MyEngine`, and this engine
+  # is mountable, there are some extra configurations to be taken into account.
+  # The following options are available, assuming the engine is mounted as:
+  #
+  #     mount MyEngine, at: '/my_engine'
+  #
+  # The router that invoked `devise_for`, in the example above, would be:
+  # config.router_name = :my_engine
+  #
+  # When using OmniAuth, Devise cannot automatically set OmniAuth path,
+  # so you need to do it manually. For the users scope, it would be:
+  # config.omniauth_path_prefix = '/my_engine/users/auth'
+
+  # ==> Hotwire/Turbo configuration
+  # When using Devise with Hotwire/Turbo, the http status for error responses
+  # and some redirects must match the following. The default in Devise for existing
+  # apps is `200 OK` and `302 Found` respectively, but new apps are generated with
+  # these new defaults that match Hotwire/Turbo behavior.
+  # Note: These might become the new default in future versions of Devise.
+  config.responder.error_status = :unprocessable_entity
+  config.responder.redirect_status = :see_other
+
+  # ==> Configuration for :registerable
+
+  # When set to false, does not sign a user in automatically after their password is
+  # changed. Defaults to true, so a user is signed in automatically after changing a password.
+  # config.sign_in_after_change_password = true
+end

config/locales/devise.en.yml

@@ -0,0 +1,65 @@
+# Additional translations at https://github.com/heartcombo/devise/wiki/I18n
+
+en:
+  devise:
+    confirmations:
+      confirmed: "Your email address has been successfully confirmed."
+      send_instructions: "You will receive an email with instructions for how to confirm your email address in a few minutes."
+      send_paranoid_instructions: "If your email address exists in our database, you will receive an email with instructions for how to confirm your email address in a few minutes."
+    failure:
+      already_authenticated: "You are already signed in."
+      inactive: "Your account is not activated yet."
+      invalid: "Invalid %{authentication_keys} or password."
+      locked: "Your account is locked."
+      last_attempt: "You have one more attempt before your account is locked."
+      not_found_in_database: "Invalid %{authentication_keys} or password."
+      timeout: "Your session expired. Please sign in again to continue."
+      unauthenticated: "You need to sign in or sign up before continuing."
+      unconfirmed: "You have to confirm your email address before continuing."
+    mailer:
+      confirmation_instructions:
+        subject: "Confirmation instructions"
+      reset_password_instructions:
+        subject: "Reset password instructions"
+      unlock_instructions:
+        subject: "Unlock instructions"
+      email_changed:
+        subject: "Email Changed"
+      password_change:
+        subject: "Password Changed"
+    omniauth_callbacks:
+      failure: "Could not authenticate you from %{kind} because \"%{reason}\"."
+      success: "Successfully authenticated from %{kind} account."
+    passwords:
+      no_token: "You can't access this page without coming from a password reset email. If you do come from a password reset email, please make sure you used the full URL provided."
+      send_instructions: "You will receive an email with instructions on how to reset your password in a few minutes."
+      send_paranoid_instructions: "If your email address exists in our database, you will receive a password recovery link at your email address in a few minutes."
+      updated: "Your password has been changed successfully. You are now signed in."
+      updated_not_active: "Your password has been changed successfully."
+    registrations:
+      destroyed: "Bye! Your account has been successfully cancelled. We hope to see you again soon."
+      signed_up: "Welcome! You have signed up successfully."
+      signed_up_but_inactive: "You have signed up successfully. However, we could not sign you in because your account is not yet activated."
+      signed_up_but_locked: "You have signed up successfully. However, we could not sign you in because your account is locked."
+      signed_up_but_unconfirmed: "A message with a confirmation link has been sent to your email address. Please follow the link to activate your account."
+      update_needs_confirmation: "You updated your account successfully, but we need to verify your new email address. Please check your email and follow the confirmation link to confirm your new email address."
+      updated: "Your account has been updated successfully."
+      updated_but_not_signed_in: "Your account has been updated successfully, but since your password was changed, you need to sign in again."
+    sessions:
+      signed_in: "Signed in successfully."
+      signed_out: "Signed out successfully."
+      already_signed_out: "Signed out successfully."
+    unlocks:
+      send_instructions: "You will receive an email with instructions for how to unlock your account in a few minutes."
+      send_paranoid_instructions: "If your account exists, you will receive an email with instructions for how to unlock it in a few minutes."
+      unlocked: "Your account has been unlocked successfully. Please sign in to continue."
+  errors:
+    messages:
+      already_confirmed: "was already confirmed, please try signing in"
+      confirmation_period_expired: "needs to be confirmed within %{period}, please request a new one"
+      expired: "has expired, please request a new one"
+      not_found: "not found"
+      not_locked: "was not locked"
+      not_saved:
+        one: "1 error prohibited this %{resource} from being saved:"
+        other: "%{count} errors prohibited this %{resource} from being saved:"

config/locales/devise.ja.yml

@@ -0,0 +1,63 @@
+ja:
+  devise:
+    confirmations:
+      confirmed: "アカウントを登録しました。"
+      send_instructions: "登録方法を数分以内にメールでご連絡します。"
+      send_paranoid_instructions: "メールアドレスが登録済みの場合、数分以内にアカウントの確認方法をメールでご連絡します。"
+    failure:
+      already_authenticated: "既にログインしています。"
+      inactive: "アカウントが有効化されていません。"
+      invalid: "%{authentication_keys}またはパスワードが違います。"
+      locked: "アカウントがロックされています。"
+      last_attempt: "もう一回誤るとアカウントがロックされます。"
+      not_found_in_database: "%{authentication_keys}またはパスワードが違います。"
+      timeout: "セッションがタイムアウトしました。もう一度ログインしてください。"
+      unauthenticated: "ログインもしくはアカウント登録してください。"
+      unconfirmed: "メールアドレスの本人確認が必要です。"
+    mailer:
+      confirmation_instructions:
+        subject: "アカウントの有効化について"
+      reset_password_instructions:
+        subject: "パスワードの再設定について"
+      unlock_instructions:
+        subject: "アカウントのロック解除について"
+      email_changed:
+        subject: "メールアドレスの変更について"
+      password_change:
+        subject: "パスワードの変更について"
+    omniauth_callbacks:
+      failure: "%{kind} アカウントによる認証に失敗しました。理由：（%{reason}）"
+      success: "%{kind} アカウントによる認証に成功しました。"
+    passwords:
+      no_token: "このページにはアクセスできません。パスワード再設定メールのリンクからアクセスされた場合には、URL をご確認ください。"
+      send_instructions: "パスワードの再設定について数分以内にメールでご連絡いたします。"
+      send_paranoid_instructions: "メールアドレスが登録済みの場合、パスワード再設定用のメールが数分以内に送信されます。"
+      updated: "パスワードが正しく変更されました。"
+      updated_not_active: "パスワードが正しく変更されました。"
+    registrations:
+      destroyed: "アカウントを削除しました。またのご利用をお待ちしております。"
+      signed_up: "アカウント登録が完了しました。"
+      signed_up_but_inactive: "ログインするためには、アカウントを有効化してください。"
+      signed_up_but_locked: "アカウントがロックされているためログインできません。"
+      signed_up_but_unconfirmed: "本人確認用のメールを送信しました。メール内のリンクからアカウントを有効化させてください。"
+      update_needs_confirmation: "アカウント情報を変更しました。変更されたメールアドレスの本人確認のため、本人確認用メールより確認処理をおこなってください。"
+      updated: "アカウント情報を変更しました。"
+      updated_but_not_signed_in: "あなたのアカウントは正常に更新されましたが、パスワードが変更されたため、再度ログインしてください。"
+    sessions:
+      signed_in: "ログインしました。"
+      signed_out: "ログアウトしました。"
+      already_signed_out: "既にログアウト済みです。"
+    unlocks:
+      send_instructions: "アカウントのロック解除方法を数分以内にメールでご連絡します。"
+      send_paranoid_instructions: "アカウントが見つかった場合、アカウントのロック解除方法を数分以内にメールでご連絡します。"
+      unlocked: "アカウントをロック解除しました。"
+  errors:
+    messages:
+      already_confirmed: "は既に登録済みです。ログインしてください。"
+      confirmation_period_expired: "の期限が切れました。%{period} までに確認する必要があります。 新しくリクエストしてください。"
+      expired: "の有効期限が切れました。新しくリクエストしてください。"
+      not_found: "は見つかりませんでした。"
+      not_locked: "はロックされていません。"
+      not_saved:
+        one: "エラーが発生したため %{resource} は保存されませんでした:"
+        other: "%{count} 件のエラーが発生したため %{resource} は保存されませんでした:"

config/routes.rb

@@ -1,4 +1,5 @@
 Rails.application.routes.draw do
+  devise_for :users
   get 'memos/index'
   get 'memos/new'
   get 'memos/edit'

db/migrate/20250223004442_devise_create_users.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+class DeviseCreateUsers < ActiveRecord::Migration[8.0]
+  def change
+    create_table :users do |t|
+      ## Database authenticatable
+      t.string :email,              null: false, default: ""
+      t.string :encrypted_password, null: false, default: ""
+
+      ## Recoverable
+      t.string   :reset_password_token
+      t.datetime :reset_password_sent_at
+
+      ## Rememberable
+      t.datetime :remember_created_at
+
+      ## Trackable
+      # t.integer  :sign_in_count, default: 0, null: false
+      # t.datetime :current_sign_in_at
+      # t.datetime :last_sign_in_at
+      # t.string   :current_sign_in_ip
+      # t.string   :last_sign_in_ip
+
+      ## Confirmable
+      # t.string   :confirmation_token
+      # t.datetime :confirmed_at
+      # t.datetime :confirmation_sent_at
+      # t.string   :unconfirmed_email # Only if using reconfirmable
+
+      ## Lockable
+      # t.integer  :failed_attempts, default: 0, null: false # Only if lock strategy is :failed_attempts
+      # t.string   :unlock_token # Only if unlock strategy is :email or :both
+      # t.datetime :locked_at
+
+
+      t.timestamps null: false
+    end
+
+    add_index :users, :email,                unique: true
+    add_index :users, :reset_password_token, unique: true
+    # add_index :users, :confirmation_token,   unique: true
+    # add_index :users, :unlock_token,         unique: true
+  end
+end

db/schema.rb

@@ -10,10 +10,22 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2025_02_19_123840) do
+ActiveRecord::Schema[8.0].define(version: 2025_02_23_004442) do
   create_table "memos", force: :cascade do |t|
     t.text "content", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
   end
+
+  create_table "users", force: :cascade do |t|
+    t.string "email", default: "", null: false
+    t.string "encrypted_password", default: "", null: false
+    t.string "reset_password_token"
+    t.datetime "reset_password_sent_at"
+    t.datetime "remember_created_at"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["email"], name: "index_users_on_email", unique: true
+    t.index ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true
+  end
 end

test/fixtures/users.yml

@@ -0,0 +1,11 @@
+# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+# This model initially had no columns defined. If you add columns to the
+# model remove the "{}" from the fixture names and add the columns immediately
+# below each fixture, per the syntax in the comments below
+#
+one: {}
+# column: value
+#
+two: {}
+# column: value

test/models/user_test.rb

@@ -0,0 +1,7 @@
+require "test_helper"
+
+class UserTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end