Allow to log out sessions

.rubocop.yml

@@ -11,6 +11,10 @@ AllCops:
 GraphQL/ExtractInputType:
   Enabled: false
 
+Lint/AmbiguousBlockAssociation:
+  AllowedMethods: [change]
+
+
 Metrics/AbcSize:
   Enabled: false
 

Gemfile

@@ -69,3 +69,5 @@ gem 'seed-fu', '~> 2.3'
 gem 'sidekiq', '~> 7.1'
 
 gem 'lograge', '~> 0.14.0'
+
+gem 'declarative_policy', '~> 1.1'

Gemfile.lock

@@ -97,6 +97,7 @@ GEM
       irb (>= 1.5.0)
       reline (>= 0.3.1)
     debug_inspector (1.1.0)
+    declarative_policy (1.1.0)
     diff-lcs (1.5.0)
     docile (1.4.0)
     drb (2.2.0)
@@ -318,6 +319,7 @@ DEPENDENCIES
   bootsnap
   database_cleaner-active_record (~> 2.1)
   debug
+  declarative_policy (~> 1.1)
   factory_bot_rails (~> 6.2)
   graphql (~> 2.1)
   lograge (~> 0.14.0)

app/controllers/graphql_controller.rb

@@ -101,7 +101,11 @@ def mutations_allowed?
       false
     end
 
-    %i[none invalid session].each do |t|
+    def invalid?
+      (authorization.nil? && !none?) || type == :invalid
+    end
+
+    %i[none session].each do |t|
       define_method :"#{t}?" do
         type == t
       end

app/graphql/mutations/base_mutation.rb

@@ -21,5 +21,9 @@ def self.require_one_of(arguments, context)
     field :errors, [GraphQL::Types::String],
           null: false,
           description: 'Errors encountered during execution of the mutation.'
+
+    def current_user
+      context[:current_user]
+    end
   end
 end

app/graphql/mutations/users/logout.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+module Mutations
+  module Users
+    class Logout < BaseMutation
+      description 'Logout an existing user session'
+
+      field :user_session, Types::UserSessionType, null: true, description: 'The logged out user session'
+
+      argument :user_session_id, Types::GlobalIdType[::UserSession], required: true,
+                                                                     description: 'ID of the session to logout'
+
+      def resolve(user_session_id:)
+        user_session = SagittariusSchema.object_from_id(user_session_id)
+
+        return { user_session: nil, errors: ['Invalid user session'] } if user_session.nil?
+
+        UserLogoutService.new(current_user, user_session).execute.to_mutation_response(success_key: :user_session)
+      end
+    end
+  end
+end

app/graphql/types/mutation_type.rb

@@ -7,6 +7,7 @@ class MutationType < Types::BaseObject
     include Sagittarius::Graphql::MountMutation
 
     mount_mutation Mutations::Users::Login
+    mount_mutation Mutations::Users::Logout
     mount_mutation Mutations::Users::Register
 
     field :echo, GraphQL::Types::String, null: false,

app/graphql/types/user_session_type.rb

@@ -4,6 +4,8 @@ module Types
   class UserSessionType < Types::BaseObject
     description 'Represents a user session'
 
+    field :active, GraphQL::Types::Boolean, null: false,
+                                            description: 'Whether or not the session is active and can be used'
     field :id, Types::GlobalIdType[::UserSession], null: false, description: 'GlobalID of the user'
     field :token, String, null: true, description: 'Token belonging to the session, only present on creation'
     field :user, Types::UserType, null: false, description: 'User that belongs to the session'

app/models/ability.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module Ability
+  module_function
+
+  def allowed?(user, ability, subject = :global)
+    policy = policy_for(user, subject)
+
+    policy.allowed?(ability)
+  end
+
+  def policy_for(user, subject = :global)
+    Cache.policies ||= {}
+
+    DeclarativePolicy.policy_for(user, subject, cache: Cache.policies)
+  end
+
+  class Cache < ActiveSupport::CurrentAttributes
+    attribute :policies
+  end
+end

app/policies/base_policy.rb

@@ -0,0 +1,4 @@
+# frozen_string_literal: true
+
+class BasePolicy < DeclarativePolicy::Base
+end

app/policies/user_session_policy.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class UserSessionPolicy < BasePolicy
+  condition(:session_owner) { @subject.user_id == @user&.id }
+
+  rule { session_owner }.enable :logout_session
+end

app/services/service_response.rb

@@ -40,7 +40,7 @@ def to_mutation_response(success_key: :object)
     if payload.is_a?(ActiveModel::Errors)
       { success_key => nil, errors: payload.full_messages }
     else
-      { success_key => nil, errors: payload }
+      { success_key => nil, errors: Array.wrap(payload) }
     end
   end
 end

app/services/user_logout_service.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+class UserLogoutService
+  include Sagittarius::Loggable
+
+  def initialize(current_user, user_session)
+    @current_user = current_user
+    @user_session = user_session
+  end
+
+  def execute
+    unless Ability.allowed?(@current_user, :logout_session, @user_session)
+      return ServiceResponse.error(payload: "You can't log out this session")
+    end
+
+    @user_session.active = false
+
+    if @user_session.save
+      logger.info(message: 'Logged out session', session_id: @user_session.id, user_id: @user_session.user_id)
+      ServiceResponse.success(message: 'Logged out session', payload: @user_session)
+    else
+      logger.warn(message: 'Failed to log out session', session_id: @user_session.id, user_id: @user_session.user_id)
+      ServiceResponse.error(payload: 'Failed to log out session')
+    end
+  end
+end

spec/graphql/types/user_session_type_spec.rb

@@ -8,6 +8,7 @@
       id
       user
       token
+      active
     ]
   end
 

spec/policies/user_session_policy_spec.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe UserSessionPolicy do
+  subject { described_class.new(current_user, user_session) }
+
+  let(:current_user) { nil }
+  let(:user_session) { nil }
+
+  context 'when user is owner of the session' do
+    let(:current_user) { create(:user) }
+    let(:user_session) { create(:user_session, user: current_user) }
+
+    it { is_expected.to be_allowed(:logout_session) }
+  end
+
+  context 'when user is not owner of the session' do
+    let(:current_user) { create(:user) }
+    let(:user_session) { create(:user_session) }
+
+    it { is_expected.not_to be_allowed(:logout_session) }
+  end
+
+  context 'when user is nil' do
+    let(:current_user) { nil }
+    let(:user_session) { create(:user_session) }
+
+    it { is_expected.not_to be_allowed(:logout_session) }
+  end
+end

spec/requests/graphql/mutation/users/logout_spec.rb

@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe 'usersLogout Mutation' do
+  include GraphqlHelpers
+
+  let(:mutation) do
+    <<~QUERY
+      mutation($input: UsersLogoutInput!) {
+        usersLogout(input: $input) {
+          errors
+          userSession {
+            id
+            active
+          }
+        }
+      }
+    QUERY
+  end
+
+  let(:user_session_id) { nil }
+  let(:current_user) { nil }
+  let(:variables) { { input: { userSessionId: user_session_id } } }
+
+  before { post_graphql mutation, variables: variables, current_user: current_user }
+
+  context 'when input is valid' do
+    let(:user_session) { create(:user_session) }
+    let(:user_session_id) { user_session.to_global_id.to_s }
+
+    context 'when logging out a session of the same user' do
+      let(:current_user) { user_session.user }
+
+      it 'logs out the session', :aggregate_failures do
+        expect(graphql_data_at(:users_logout, :user_session, :id)).to eq(user_session_id)
+        expect(graphql_data_at(:users_logout, :user_session, :active)).to be(false)
+      end
+    end
+
+    context 'when logging out a session of another user' do
+      let(:current_user) { create(:user) }
+
+      it 'does not log out the session', :aggregate_failures do
+        expect(graphql_data_at(:users_logout, :errors)).to include("You can't log out this session")
+        expect(graphql_data_at(:users_logout, :user_session)).to be_nil
+      end
+    end
+  end
+
+  context 'when input is invalid' do
+    let(:current_user) { create(:user) }
+
+    context 'when session id is invalid' do
+      let(:user_session_id) { 'some random string' }
+
+      it 'raises validation error' do
+        expect(graphql_errors).to include(
+          a_hash_including(
+            'message' => a_string_including("Could not coerce value \"#{user_session_id}\" to UserSessionID")
+          )
+        )
+      end
+    end
+
+    context 'when session id is does not exist' do
+      let(:user_session_id) { 'gid://Sagittarius/UserSession/0' }
+
+      it 'raises validation error' do
+        expect(graphql_data_at(:users_logout, :errors)).to include('Invalid user session')
+      end
+    end
+  end
+end

spec/services/user_logout_service_spec.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe UserLogoutService do
+  subject(:service_response) { described_class.new(current_user, user_session).execute }
+
+  context 'when current_user can log out user_session' do
+    let(:current_user) { create(:user) }
+    let(:user_session) { create(:user_session, user: current_user) }
+
+    it { is_expected.to be_success }
+
+    it 'changes the session to inactive' do
+      expect { service_response }.to change { user_session.reload.active }.from(true).to(false)
+    end
+  end
+
+  context 'when current_user can not log out user_session' do
+    let(:current_user) { create(:user) }
+    let(:user_session) { create(:user_session) }
+
+    it { is_expected.not_to be_success }
+
+    it 'does not change the session to inactive' do
+      expect { service_response }.not_to change { user_session.reload.active }
+    end
+  end
+
+  context 'when current_user is nil' do
+    let(:current_user) { nil }
+    let(:user_session) { create(:user_session) }
+
+    it { is_expected.not_to be_success }
+
+    it 'does not change the session to inactive' do
+      expect { service_response }.not_to change { user_session.reload.active }
+    end
+  end
+end

spec/support/helpers/graphql_helpers.rb

@@ -46,7 +46,7 @@ def graphql_dig_at(data, *path)
     keys = path.map { |segment| segment.is_a?(Integer) ? segment : GraphqlHelpers.graphql_field_name(segment) }
 
     keys.reduce(data) do |acc, cur|
-      if acc.is_a?(Array) && key.is_a?(Integer)
+      if acc.is_a?(Array) && cur.is_a?(Integer)
         acc[cur]
       elsif acc.is_a?(Array)
         acc.compact.pluck(cur)