Slowly getting the nested controllers working

More tests required

app/models/credential.rb

@@ -1,4 +1,5 @@
 class Credential < ApplicationRecord
+    belongs_to :domain
     validates :email, presence: true
     validates :email, uniqueness: true
     validates :email, format: { with: /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i , message: "email must be valid"}

app/models/domain.rb

@@ -1,4 +1,6 @@
 class Domain < ApplicationRecord
+    has_many :credentials, dependent: :destroy
+    has_many :virtuals, dependent: :destroy
     validates :domain, presence: true
     validates :domain, uniqueness: true
 end

app/models/virtual.rb

@@ -1,4 +1,5 @@
 class Virtual < ApplicationRecord
+    belongs_to :domain
     validate :domain_name_exists
     validates :email, presence: true
     validates :destination, presence: true