Validate path uniqueness only on Route, and bubble up appropriately

app/models/concerns/routable.rb

@@ -7,11 +7,12 @@ module Routable
     has_one :route, as: :source, autosave: true, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
     has_many :redirect_routes, as: :source, autosave: true, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
-    validates_associated :route
     validates :route, presence: true
     scope :with_route, -> { includes(:route) }
+    after_validation :set_path_errors
+
     before_validation do
       if full_path_changed? || full_name_changed?
         prepare_route
@@ -125,6 +126,11 @@ module Routable
   private
+  def set_path_errors
+    route_path_errors = self.errors.delete(:"route.path")
+    self.errors[:path].concat(route_path_errors) if route_path_errors
+  end
+
   def uncached_full_path
     if route && route.path.present?
       @full_path ||= route.path # rubocop:disable Gitlab/ModuleWithInstanceVariables

app/models/namespace.rb

@@ -32,7 +32,6 @@ class Namespace < ActiveRecord::Base
   validates :owner, presence: true, unless: ->(n) { n.type == "Group" }
   validates :name,
     presence: true,
-    uniqueness: { scope: :parent_id },
     length: { maximum: 255 },
     namespace_name: true

app/models/project.rb

@@ -245,8 +245,7 @@ class Project < ActiveRecord::Base
   validates :path,
     presence: true,
     project_path: true,
-    length: { maximum: 255 },
-    uniqueness: { scope: :namespace_id }
+    length: { maximum: 255 }
   validates :namespace, presence: true
   validates :name, uniqueness: { scope: :namespace_id }

app/models/route.rb

@@ -75,7 +75,7 @@ class Route < ActiveRecord::Base
   def ensure_permanent_paths
     return if path.nil?
-    errors.add(:path, "#{path} has been taken before. Please use another one") if conflicting_redirect_exists?
+    errors.add(:path, "has been taken before") if conflicting_redirect_exists?
   end
   def conflicting_redirect_exists?

app/models/user.rb

@@ -153,10 +153,9 @@ class User < ActiveRecord::Base
     numericality: { greater_than_or_equal_to: 0, less_than_or_equal_to: Gitlab::Database::MAX_INT_VALUE }
   validates :username,
     user_path: true,
-    presence: true,
-    uniqueness: { case_sensitive: false }
-  validate :namespace_uniq, if: :username_changed?
+    presence: true
+  validates :namespace, presence: true
   validate :namespace_move_dir_allowed, if: :username_changed?
   validate :unique_email, if: :email_changed?
@@ -172,6 +171,7 @@ class User < ActiveRecord::Base
   before_save :skip_reconfirmation!, if: ->(user) { user.email_changed? && user.read_only_attribute?(:email) }
   before_save :check_for_verified_email, if: ->(user) { user.email_changed? && !user.new_record? }
   before_validation :ensure_namespace_correct
+  after_validation :set_username_errors
   after_update :username_changed_hook, if: :username_changed?
   after_destroy :post_destroy_hook
   after_destroy :remove_key_cache
@@ -505,17 +505,6 @@ class User < ActiveRecord::Base
     end
   end
-  def namespace_uniq
-    # Return early if username already failed the first uniqueness validation
-    return if errors.key?(:username) &&
-        errors[:username].include?('has already been taken')
-
-    existing_namespace = Namespace.by_path(username)
-    if existing_namespace && existing_namespace != namespace
-      errors.add(:username, 'has already been taken')
-    end
-  end
-
   def namespace_move_dir_allowed
     if namespace&.any_project_has_container_registry_tags?
       errors.add(:username, 'cannot be changed if a personal project has container registry tags.')
@@ -891,6 +880,11 @@ class User < ActiveRecord::Base
     end
   end
+  def set_username_errors
+    namespace_path_errors = self.errors.delete(:"namespace.path")
+    self.errors[:username].concat(namespace_path_errors) if namespace_path_errors
+  end
+
   def username_changed_hook
     system_hook_service.execute_hooks_for(self, :rename)
   end

spec/models/concerns/routable_spec.rb

@@ -39,7 +39,7 @@ describe Group, 'Routable' do
       create(:group, parent: group, path: 'xyz')
       duplicate = build(:project, namespace: group, path: 'xyz')
-      expect { duplicate.save! }.to raise_error(ActiveRecord::RecordInvalid, 'Validation failed: Route path has already been taken, Route is invalid')
+      expect { duplicate.save! }.to raise_error(ActiveRecord::RecordInvalid, 'Validation failed: Path has already been taken')
     end
   end

spec/models/group_spec.rb

@@ -41,7 +41,6 @@ describe Group do
   describe 'validations' do
     it { is_expected.to validate_presence_of :name }
-    it { is_expected.to validate_uniqueness_of(:name).scoped_to(:parent_id) }
     it { is_expected.to validate_presence_of :path }
     it { is_expected.not_to validate_presence_of :owner }
     it { is_expected.to validate_presence_of :two_factor_grace_period }

spec/models/namespace_spec.rb

@@ -15,7 +15,6 @@ describe Namespace do
   describe 'validations' do
     it { is_expected.to validate_presence_of(:name) }
-    it { is_expected.to validate_uniqueness_of(:name).scoped_to(:parent_id) }
     it { is_expected.to validate_length_of(:name).is_at_most(255) }
     it { is_expected.to validate_length_of(:description).is_at_most(255) }
     it { is_expected.to validate_presence_of(:path) }

spec/models/project_spec.rb

@@ -129,7 +129,6 @@ describe Project do
     it { is_expected.to validate_length_of(:name).is_at_most(255) }
     it { is_expected.to validate_presence_of(:path) }
-    it { is_expected.to validate_uniqueness_of(:path).scoped_to(:namespace_id) }
     it { is_expected.to validate_length_of(:path).is_at_most(255) }
     it { is_expected.to validate_length_of(:description).is_at_most(2000) }

spec/models/route_spec.rb

@@ -27,7 +27,7 @@ describe Route do
             redirect.save!(validate: false)
             expect(new_route.valid?).to be_falsey
-            expect(new_route.errors.first[1]).to eq('foo has been taken before. Please use another one')
+            expect(new_route.errors.first[1]).to eq('has been taken before')
           end
         end
@@ -49,7 +49,7 @@ describe Route do
             redirect.save!(validate: false)
             expect(route.valid?).to be_falsey
-            expect(route.errors.first[1]).to eq('foo has been taken before. Please use another one')
+            expect(route.errors.first[1]).to eq('has been taken before')
           end
         end
@@ -368,7 +368,7 @@ describe Route do
         group2.path = 'foo'
         group2.valid?
-        expect(group2.errors["route.path"].first).to eq('foo has been taken before. Please use another one')
+        expect(group2.errors[:path]).to eq(['has been taken before'])
       end
     end

spec/models/user_spec.rb

@@ -116,12 +116,6 @@ describe User do
         expect(user).to be_valid
       end
-      it 'validates uniqueness' do
-        user = build(:user)
-
-        expect(user).to validate_uniqueness_of(:username).case_insensitive
-      end
-
       context 'when username is changed' do
         let(:user) { build_stubbed(:user, username: 'old_path', namespace: build_stubbed(:namespace)) }
@@ -2287,17 +2281,17 @@ describe User do
           end
           context 'when there is a validation error (namespace name taken) while updating namespace' do
-            let!(:conflicting_namespace) { create(:group, name: new_username, path: 'quz') }
+            let!(:conflicting_namespace) { create(:group, path: new_username) }
             it 'causes the user save to fail' do
               expect(user.update_attributes(username: new_username)).to be_falsey
-              expect(user.namespace.errors.messages[:name].first).to eq('has already been taken')
+              expect(user.namespace.errors.messages[:path].first).to eq('has already been taken')
             end
             it 'adds the namespace errors to the user' do
               user.update_attributes(username: new_username)
-              expect(user.errors.full_messages.first).to eq('Namespace name has already been taken')
+              expect(user.errors.full_messages.first).to eq('Username has already been taken')
             end
           end
         end

spec/services/users/update_service_spec.rb

@@ -21,13 +21,13 @@ describe Users::UpdateService do
     end
     it 'includes namespace error messages' do
-      create(:group, name: 'taken', path: 'something_else')
+      create(:group, path: 'taken')
       result = {}
       expect do
         result = update_user(user, { username: 'taken' })
       end.not_to change { user.reload.username }
       expect(result[:status]).to eq(:error)
-      expect(result[:message]).to eq('Namespace name has already been taken')
+      expect(result[:message]).to eq('Username has already been taken')
     end
     def update_user(user, opts)