better handle 500 error

app/controllers/application_controller.rb

@@ -13,6 +13,10 @@ class ApplicationController < ActionController::Base
     render "errors/not_found", status: :unauthorized
   end
 
+  def render_internal_server_error
+    render "errors/internal_server_error", status: :internal_server_error
+  end
+
   def render_not_found_json(class_name, id)
     render json: { error: "#{class_name} #{id} not found" }, status: :not_found
   end

app/controllers/lettings_logs_controller.rb

@@ -75,7 +75,7 @@ class LettingsLogsController < LogsController
     if @log.delete
       redirect_to lettings_logs_path, notice: "Log #{@log.id} has been deleted"
     else
-      render_not_found
+      render_internal_server_error
     end
   end
 

app/controllers/sales_logs_controller.rb

@@ -50,7 +50,7 @@ class SalesLogsController < LogsController
     if @log.delete
       redirect_to sales_logs_path, notice: "Log #{@log.id} has been deleted"
     else
-      render_not_found
+      render_internal_server_error
     end
   end
 

spec/requests/lettings_logs_controller_spec.rb

@@ -1323,6 +1323,19 @@ RSpec.describe LettingsLogsController, type: :request do
       sign_in user
     end
 
+    # rubocop:disable RSpec/AnyInstance
+    context "when log deletion errors" do
+      before do
+        allow_any_instance_of(LettingsLog).to receive(:delete).and_return(false)
+      end
+
+      it "renders 500 page" do
+        delete_request
+        expect(response).to have_http_status(:internal_server_error)
+      end
+    end
+    # rubocop:enable RSpec/AnyInstance
+
     context "when delete permitted" do
       it "redirects to lettings logs and shows message" do
         delete_request

spec/requests/sales_logs_controller_spec.rb

@@ -668,6 +668,19 @@ RSpec.describe SalesLogsController, type: :request do
       sign_in user
     end
 
+    # rubocop:disable RSpec/AnyInstance
+    context "when log deletion errors" do
+      before do
+        allow_any_instance_of(SalesLog).to receive(:delete).and_return(false)
+      end
+
+      it "renders 500 page" do
+        delete_request
+        expect(response).to have_http_status(:internal_server_error)
+      end
+    end
+    # rubocop:enable RSpec/AnyInstance
+
     context "when delete permitted" do
       it "redirects to sales logs and shows message" do
         delete_request