Show errors when has_many restrict_with_error.

* Return full_messages with new line separator

app/controllers/administrate/application_controller.rb

@@ -67,8 +67,12 @@ def update
     end
 
     def destroy
-      requested_resource.destroy
-      flash[:notice] = translate_with_resource("destroy.success")
+      if requested_resource.destroy
+        flash[:notice] = translate_with_resource("destroy.success")
+      else
+        flash[:error] = requested_resource.errors.
+          full_messages.join("<br/>").html_safe
+      end
       redirect_to action: :index
     end
 

spec/example_app/app/models/order.rb

@@ -3,7 +3,7 @@ class Order < ActiveRecord::Base
 
   validates :customer, presence: true
   has_many :line_items, dependent: :destroy
-  has_many :payments, dependent: :destroy
+  has_many :payments, dependent: :restrict_with_error
 
   validates :address_line_one, presence: true
   validates :address_line_two, presence: true

spec/features/orders_index_spec.rb

@@ -55,4 +55,15 @@
       t("administrate.controller.destroy.success", resource: "Order")
     )
   end
+
+  scenario "cannot delete because associated payment" do
+    create(:payment, order: create(:order))
+
+    visit admin_orders_path
+    click_on t("administrate.actions.destroy")
+
+    expect(page).to have_flash(
+      "Cannot delete record because dependent payments exist", type: :error
+    )
+  end
 end

spec/models/order_spec.rb

@@ -24,6 +24,17 @@
     expect(LineItem.all).to be_empty
   end
 
+  it "raise error when try delete associated payment" do
+    order = create(:order)
+    create(:payment, order: order)
+
+    order.destroy
+
+    expect(order.errors[:base]).to eq(
+      ["Cannot delete record because dependent payments exist"],
+    )
+  end
+
   describe "#total_price" do
     it "returns 0 when there are no line items" do
       order = build(:order)

spec/support/have_flash_matcher.rb

@@ -1,5 +1,6 @@
 module Features
-  def have_flash(text)
-    have_css(".flash-notice", text: text)
+  def have_flash(text, options = {})
+    options.reverse_merge!(type: :notice)
+    have_css(".flash-#{options[:type]}", text: text)
   end
 end