Prevent creating shifts in the past

.rubocop.yml

@@ -28,3 +28,7 @@ Style/WordArray:
 
 Style/Documentation:
   Enabled: false
+
+Metrics/MethodLength:
+  Exclude:
+    - db/migrate/**/*.rb

app/gateways/rest/api/shifts/create.rb

@@ -4,6 +4,14 @@ module REST
   class API
     class Shifts
       class Create < Base
+        helpers do
+          def handle_operation_errors
+            yield
+          rescue ::Shift::DoubleBookError, ::Shift::PastStartError => error
+            wrapped_error!({ start_at: error.message }, 422, as: :attributes)
+          end
+        end
+
         class Contract < Dry::Validation::Contract
           json do
             required(:worker_id).filled(:string)
@@ -17,8 +25,10 @@ class Contract < Dry::Validation::Contract
           payload => { worker_id: external_id, attributes: { start_at: }}
           worker = ::Worker.find_by(external_id:)
           not_found(:worker_id) if worker.nil?
-          shift = ::Shift::Create.new.call(worker:, start_at:)
-          present shift, with: Serialization::Shift
+          handle_operation_errors do
+            shift = ::Shift::Create.new.call(worker:, start_at:)
+            present shift, with: Serialization::Shift
+          end
         end
       end
     end

app/operations/shift/create.rb

@@ -3,6 +3,7 @@
 class Shift
   class Create < BaseOperation
     def call(worker:, start_at:)
+      validate_start_at!(start_at)
       attributes = prepare_attributes(worker, start_at)
       handle_duplication_error do
         Shift.create!(worker:, **attributes)
@@ -13,6 +14,10 @@ def call(worker:, start_at:)
 
     private
 
+    def validate_start_at!(start_at)
+      raise PastStartError, I18n.t!("models.shift.errors.past_start") if start_at.past?
+    end
+
     def prepare_attributes(worker, start_at)
       {
         start_at: worker.local_time(start_at),

config/locales/en.yml

@@ -15,5 +15,6 @@ en:
     shift:
       errors:
         double_book: "The worker already has a shift on %{date}"
+        past_start: is in the past
 
   hello: "Hello world"

test/factories/shifts.rb

@@ -22,5 +22,9 @@
     trait :next_day do
       start_at { in_zone_time.next_day }
     end
+
+    trait :in_past do
+      start_at { in_zone_time - 7.days }
+    end
   end
 end

test/gateways/rest/api/shifts/create_test.rb

@@ -41,6 +41,12 @@ class REST::API::Shifts::CreateTest < ActionDispatch::IntegrationTest
     assert_response 422
   end
 
+  test "preventing booking a shift in the past" do
+    shift = build(:shift, :in_past, worker:)
+    execute(payload(worker, shift))
+    assert_response 422
+  end
+
   private
 
   attr_reader(