Restrict actions for unauthorized users

app/controllers/api/v1/users_controller.rb

 class Api::V1::UsersController < ApplicationController
   before_action :set_user, only: %i[show update destroy]
+  before_action :check_owner, only: %i[update destroy]
 
   def index
     render json: User.all
   def set_user
     @user = User.find(params[:id])
   end
+
+  def check_owner
+    head :forbidden unless @user.id == current_user&.id
+  end
 end

app/controllers/application_controller.rb

 class ApplicationController < ActionController::API
+  include Authenticable
 end

test/controllers/api/v1/users_controller_test.rb

 
   #UPDATE
   test "should update user" do
-    patch api_v1_user_url(@user), params: { user: { email: @user.email, username: @user.username, password: '123456' } }, as: :json
+    patch api_v1_user_url(@user),
+    params: { user: { email: @user.email, password: '123456' } },
+    headers: { Authorization: JsonWebToken.encode(user_id: @user.id) },
+    as: :json
     assert_response :success
   end
 
-  # test "should not update user when invalid params are sent" do
-  #   patch api_v1_user_url(@user), params: { user: { email: 'bad_email', username: @user.username, password: '123456' } }, as: :json
-  #   assert_response :unprocessable_entity
-  # end
+  test "should forbid update user" do
+    patch api_v1_user_url(@user),
+    params: { user: { email: @user.email, password: '123456' } },
+    as: :json
+    assert_response :forbidden
+  end
 
   #DESTROY 
   test "should destroy user" do
     assert_difference('User.count', -1) do
-      delete api_v1_user_url(@user), as: :json
+      delete api_v1_user_url(@user),
+      headers: { Authorization: JsonWebToken.encode(user_id: @user.id) },
+      as: :json
     end
     assert_response :no_content
   end
 
-  # test "should forbid destroy user" do
-  #   assert_no_difference('User.count') do
-  #     delete api_v1_user_url(@user), as: :json
-  #   end
-  #   assert_response :forbidden
-  # end
+  test "should forbid destroy user" do
+    assert_no_difference('User.count') do
+      delete api_v1_user_url(@user), as: :json
+    end
+    assert_response :forbidden
+  end
 end

test/controllers/concerns/authenticable_test.rb

+class MockController
+  include Authenticable
+  attr_accessor :request
+
+  def initialize
+    mock_request = Struct.new(:headers)
+    self.request = mock_request.new({})
+  end
+end
+
+class AuthenticableTest < ActionDispatch::IntegrationTest
+  setup do
+    @user = users(:one)
+    @authentication = MockController.new
+  end
+
+  test 'should get user from Authorization token' do
+    @authentication.request.headers['Authorization'] = JsonWebToken.encode(user_id: @user.id)
+    assert_equal @user.id, @authentication.current_user.id
+  end
+
+  test 'should not get user from empty Authorization token' do
+    @authentication.request.headers['Authorization'] = nil
+    assert_nil @authentication.current_user
+  end
+end