[v7] Use cases (Micro::Case)

Gemfile

@@ -3,6 +3,9 @@ git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
 ruby '2.6.5'
 
+gem 'u-case', '~> 2.2', require: 'u-case/with_validation'
+gem 'type_validator', '~> 1.0'
+
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '~> 6.0.1'
 # Use sqlite3 as the database for Active Record

Gemfile.lock

@@ -94,7 +94,6 @@ GEM
     i18n (1.7.0)
       concurrent-ruby (~> 1.0)
     ice_nine (0.11.2)
-    interactor (3.1.1)
     json (2.2.0)
     kwalify (0.7.2)
     launchy (2.4.3)
@@ -201,8 +200,13 @@ GEM
     thor (0.20.3)
     thread_safe (0.3.6)
     tty-which (0.4.1)
+    type_validator (1.0.0)
+      activemodel (>= 3.2)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
+    u-attributes (1.2.0)
+    u-case (2.2.0)
+      u-attributes (~> 1.1)
     virtus (1.0.5)
       axiom-types (~> 0.1)
       coercible (~> 1.0)
@@ -219,7 +223,6 @@ PLATFORMS
 DEPENDENCIES
   bootsnap (>= 1.4.2)
   byebug
-  interactor (~> 3.1)
   listen (>= 3.0.5, < 3.2)
   puma (~> 4.1)
   rails (~> 6.0.1)
@@ -228,7 +231,9 @@ DEPENDENCIES
   spring
   spring-watcher-listen (~> 2.0.0)
   sqlite3 (~> 1.4)
+  type_validator (~> 1.0)
   tzinfo-data
+  u-case (~> 2.2)
 
 RUBY VERSION
    ruby 2.6.5p114

app/controllers/todos_controller.rb

@@ -2,64 +2,50 @@ class TodosController < ApplicationController
   before_action :authenticate_user
 
   def index
-    todos = todo_list.fetch_items_by_status(params[:status])
-
-    render_json(200, todos: Todo::Serialization.map_as_json(todos))
+    Todo::List::FetchItems
+      .call(user: current_user, params: params)
+      .on_success { |result| render_json(200, todos: result[:todos]) }
   end
 
   def create
-    todo_params = Todo::Params.to_save(params)
-
-    todo = todo_list.add_item(todo_params)
-
-    status = todo.persisted? ? 201 : 422
-
-    render_json(status, todo: Todo::Serialization.as_json(todo))
-  rescue ActionController::ParameterMissing => e
-    render_json(400, error: e.message)
+    Todo::List::AddItem
+      .call(user: current_user, params: params)
+      .on_failure(:parameter_missing) { |error| render_json(400, error: error[:message]) }
+      .on_failure(:invalid_todo) { |todo| render_json(422, todo: todo[:errors]) }
+      .on_success { |result| render_json(201, todo: result[:todo]) }
   end
 
   def destroy
-    todo = todo_list.delete_item(params[:id])
-
-    render_json(200, todo: Todo::Serialization.as_json(todo))
-  rescue ActiveRecord::RecordNotFound
-    render_json(404, todo: { id: 'not found' })
+    Todo::List::DeleteItem
+      .call(user: current_user, todo_id: params[:id])
+      .on_failure(:validation_error) { |result| render_json(400, errors: result[:errors]) }
+      .on_failure(:todo_not_found) { render_json(404, todo: { id: 'not found' }) }
+      .on_success { |result| render_json(200, todo: result[:todo]) }
   end
 
   def update
-    todo_params = Todo::Params.to_save(params)
-
-    todo = todo_list.update_item(params[:id], todo_params)
-
-    status = todo.valid? ? 200 : 422
-
-    render_json(status, todo: Todo::Serialization.as_json(todo))
-  rescue ActiveRecord::RecordNotFound
-    render_json(404, todo: { id: 'not found' })
-  rescue ActionController::ParameterMissing => e
-    render_json(400, error: e.message)
+    Todo::List::UpdateItem
+      .call(user: current_user, todo_id: params[:id], params: params)
+      .on_failure(:parameter_missing) { |error| render_json(400, error: error[:message]) }
+      .on_failure(:validation_error) { |result| render_json(400, errors: result[:errors]) }
+      .on_failure(:todo_not_found) { render_json(404, todo: { id: 'not found' }) }
+      .on_failure(:invalid_todo) { |todo| render_json(422, todo: todo[:errors]) }
+      .on_success { |result| render_json(200, todo: result[:todo]) }
   end
 
   def complete
-    todo = todo_list.complete_item(params[:id])
-
-    render_json(200, todo: Todo::Serialization.as_json(todo))
-  rescue ActiveRecord::RecordNotFound
-    render_json(404, todo: { id: 'not found' })
+    Todo::List::CompleteItem
+      .call(user: current_user, todo_id: params[:id])
+      .on_failure(:validation_error) { |result| render_json(400, errors: result[:errors]) }
+      .on_failure(:todo_not_found) { render_json(404, todo: { id: 'not found' }) }
+      .on_success { |result| render_json(200, todo: result[:todo]) }
   end
 
   def activate
-    todo = todo_list.activate_item(params[:id])
-
-    render_json(200, todo: Todo::Serialization.as_json(todo))
-  rescue ActiveRecord::RecordNotFound
-    render_json(404, todo: { id: 'not found' })
+    Todo::List::ActivateItem
+      .call(user: current_user, todo_id: params[:id])
+      .on_failure(:validation_error) { |result| render_json(400, errors: result[:errors]) }
+      .on_failure(:todo_not_found) { render_json(404, todo: { id: 'not found' }) }
+      .on_success { |result| render_json(200, todo: result[:todo]) }
   end
-
-  private
-
-    def todo_list
-      @todo_list ||= Todo::List.of(current_user)
-    end
 end

app/controllers/users/registrations_controller.rb

@@ -1,15 +1,9 @@
 class Users::RegistrationsController < ApplicationController
   def create
-    user_params = User::Params.to_register(params)
-
-    user = User::Registration.new(user_params).create
-
-    if user.persisted?
-      render_json(201, user: user.as_json(only: [:id, :name, :token]))
-    else
-      render_json(422, user: user.errors.as_json)
-    end
-  rescue ActionController::ParameterMissing => e
-    render_json(400, error: e.message)
+    User::Register::Flow
+      .call(params: params)
+      .on_failure(:parameter_missing) { |error| render_json(400, error: error[:message]) }
+      .on_failure(:invalid_user_params) { |user| render_json(422, user: user[:errors]) }
+      .on_success { |result| render_json(201, user: result[:user]) }
   end
 end

app/models/todo/list/activate_item.rb

@@ -0,0 +1,18 @@
+class Todo::List::ActivateItem < Micro::Case
+  attributes :user, :todo_id
+
+  validates :user, type: User
+  validates :todo_id, numericality: { only_integer: true }
+
+  def call!
+    todo = user.todos.find_by(id: todo_id&.strip)
+
+    return Failure(:todo_not_found) unless todo
+
+    todo.completed_at = nil unless todo.active?
+
+    todo.save if todo.completed_at_changed?
+
+    Success { { todo: Todo::Serialization.as_json(todo) } }
+  end
+end

app/models/todo/list/add_item.rb

@@ -0,0 +1,20 @@
+class Todo::List::AddItem < Micro::Case
+  attributes :user, :params
+
+  validates :user, type: User
+  validates :params, type: ActionController::Parameters
+
+  def call!
+    todo_params = Todo::Params.to_save(params)
+
+    todo = user.todos.create(todo_params)
+
+    todo_as_json = Todo::Serialization.as_json(todo)
+
+    return Success { { todo: todo_as_json } } if todo.persisted?
+
+    Failure(:invalid_todo) { { errors: todo_as_json } }
+  rescue ActionController::ParameterMissing => e
+    Failure(:parameter_missing) { { message: e.message } }
+  end
+end

app/models/todo/list/complete_item.rb

@@ -0,0 +1,18 @@
+class Todo::List::CompleteItem < Micro::Case
+  attributes :user, :todo_id
+
+  validates :user, type: User
+  validates :todo_id, numericality: { only_integer: true }
+
+  def call!
+    todo = user.todos.find_by(id: todo_id&.strip)
+
+    return Failure(:todo_not_found) unless todo
+
+    todo.completed_at = Time.current unless todo.completed?
+
+    todo.save if todo.completed_at_changed?
+
+    Success { { todo: Todo::Serialization.as_json(todo) } }
+  end
+end

app/models/todo/list/delete_item.rb

@@ -0,0 +1,16 @@
+class Todo::List::DeleteItem < Micro::Case
+  attributes :user, :todo_id
+
+  validates :user, type: User
+  validates :todo_id, numericality: { only_integer: true }
+
+  def call!
+    todo = user.todos.find_by(id: todo_id&.strip)
+
+    return Failure(:todo_not_found) unless todo
+
+    todo.destroy
+
+    Success { { todo: Todo::Serialization.as_json(todo) } }
+  end
+end

app/models/todo/list/fetch_items.rb

@@ -0,0 +1,12 @@
+class Todo::List::FetchItems < Micro::Case
+  attributes :user, :params
+
+  validates :user, type: User
+  validates :params, type: ActionController::Parameters
+
+  def call!
+    todos = Todo.where_status(params[:status]).where(user_id: user.id)
+
+    Success { { todos: Todo::Serialization.map_as_json(todos) } }
+  end
+end

app/models/todo/list/update_item.rb

@@ -0,0 +1,25 @@
+class Todo::List::UpdateItem < Micro::Case
+  attributes :user, :todo_id, :params
+
+  validates :user, type: User
+  validates :params, type: ActionController::Parameters
+  validates :todo_id, numericality: { only_integer: true }
+
+  def call!
+    todo_params = Todo::Params.to_save(params)
+
+    todo = user.todos.find_by(id: todo_id&.strip)
+
+    return Failure(:todo_not_found) unless todo
+
+    todo.update(todo_params)
+
+    todo_as_json = Todo::Serialization.as_json(todo)
+
+    return Success { { todo: todo_as_json } } if todo.valid?
+
+    Failure(:invalid_todo) { { errors: todo_as_json } }
+  rescue ActionController::ParameterMissing => e
+    Failure(:parameter_missing) { { message: e.message } }
+  end
+end

app/models/user/register/flow.rb

@@ -0,0 +1,10 @@
+class User
+  module Register
+    class Flow < Micro::Case
+      flow Step::NormalizeParams,
+           Step::ValidatePassword,
+           Step::CreateRecord,
+           Step::SerializeAsJson
+    end
+  end
+end

app/models/user/register/step/create_record.rb

@@ -0,0 +1,17 @@
+class User::Register::Step::CreateRecord < Micro::Case
+  attributes :name, :password, :password_confirmation
+
+  def call!
+    user = User.new(user_attributes).tap(&:save)
+
+    return Success { { user: user } } if user.persisted?
+
+    Failure(:invalid_user_params) { { errors: user.errors.as_json } }
+  end
+
+  private
+
+    def user_attributes
+      { name: name, password_digest: password.digest, token: SecureRandom.uuid }
+    end
+end

app/models/user/register/step/normalize_params.rb

@@ -0,0 +1,19 @@
+class User::Register::Step::NormalizeParams < Micro::Case
+  attribute :params
+
+  validates! :params, type: ActionController::Parameters
+
+  def call!
+    user_params = User::Params.to_register(params)
+
+    Success do
+      {
+        name: user_params[:name].try(:squish),
+        password: User::Password.new(user_params[:password]),
+        password_confirmation: User::Password.new(user_params[:password_confirmation])
+      }
+    end
+  rescue ActionController::ParameterMissing => e
+    Failure(:parameter_missing) { { message: e.message } }
+  end
+end

app/models/user/register/step/serialize_as_json.rb

@@ -0,0 +1,11 @@
+class User::Register::Step::SerializeAsJson < Micro::Case
+  attribute :user
+
+  validates! :user, type: User
+
+  def call!
+    Success do
+      { user: user.as_json(only: [:id, :name, :token]) }
+    end
+  end
+end