Refactor access_level_inclusion into base class

Member model.

app/models/member.rb

@@ -52,6 +52,7 @@ class Member < ApplicationRecord
       message: _('project bots cannot be added to other groups / projects')
     },
     if: :project_bot?
+  validate :access_level_inclusion
 
   scope :with_invited_user_state, -> do
     joins('LEFT JOIN users as invited_user ON invited_user.email = members.invite_email')
@@ -382,6 +383,12 @@ class Member < ApplicationRecord
 
   private
 
+  def access_level_inclusion
+    return if access_level.in?(Gitlab::Access.all_values)
+
+    errors.add(:access_level, "is not included in the list")
+  end
+
   def send_invite
     # override in subclass
   end

app/models/members/group_member.rb

@@ -6,6 +6,7 @@ class GroupMember < Member
   include CreatedAtFilterable
 
   SOURCE_TYPE = 'Namespace'
+  SOURCE_TYPE_FORMAT = /\ANamespace\z/.freeze
 
   belongs_to :group, foreign_key: 'source_id'
   alias_attribute :namespace_id, :source_id
@@ -13,9 +14,7 @@ class GroupMember < Member
 
   # Make sure group member points only to group as it source
   default_value_for :source_type, SOURCE_TYPE
-  validates :source_type, format: { with: /\ANamespace\z/ }
-  validates :access_level, presence: true
-  validate :access_level_inclusion
+  validates :source_type, format: { with: SOURCE_TYPE_FORMAT }
 
   default_scope { where(source_type: SOURCE_TYPE) } # rubocop:disable Cop/DefaultScope
 
@@ -65,12 +64,6 @@ class GroupMember < Member
     super
   end
 
-  def access_level_inclusion
-    return if access_level.in?(Gitlab::Access.all_values)
-
-    errors.add(:access_level, "is not included in the list")
-  end
-
   def send_invite
     run_after_commit_or_now { notification_service.invite_group_member(self, @raw_invite_token) }
 

app/models/members/project_member.rb

@@ -3,6 +3,7 @@
 class ProjectMember < Member
   extend ::Gitlab::Utils::Override
   SOURCE_TYPE = 'Project'
+  SOURCE_TYPE_FORMAT = /\AProject\z/.freeze
 
   belongs_to :project, foreign_key: 'source_id'
 
@@ -10,8 +11,7 @@ class ProjectMember < Member
 
   # Make sure project member points only to project as it source
   default_value_for :source_type, SOURCE_TYPE
-  validates :source_type, format: { with: /\AProject\z/ }
-  validates :access_level, inclusion: { in: Gitlab::Access.values }
+  validates :source_type, format: { with: SOURCE_TYPE_FORMAT }
   default_scope { where(source_type: SOURCE_TYPE) } # rubocop:disable Cop/DefaultScope
 
   scope :in_project, ->(project) { where(source_id: project.id) }
@@ -92,6 +92,13 @@ class ProjectMember < Member
 
   private
 
+  override :access_level_inclusion
+  def access_level_inclusion
+    return if access_level.in?(Gitlab::Access.values)
+
+    errors.add(:access_level, "is not included in the list")
+  end
+
   override :refresh_member_authorized_projects
   def refresh_member_authorized_projects(blocking:)
     return unless user