Allow Limitable to use override feature flag

Changelog: added

app/models/concerns/limitable.rb

@@ -9,6 +9,7 @@ module Limitable
     class_attribute :limit_relation
     class_attribute :limit_name
     class_attribute :limit_feature_flag
+    class_attribute :limit_feature_flag_for_override # Allows selectively disabling by actor (as per https://docs.gitlab.com/ee/development/feature_flags/#selectively-disable-by-actor)
     self.limit_name = self.name.demodulize.tableize
 
     validate :validate_plan_limit_not_exceeded, on: :create
@@ -28,6 +29,7 @@ def validate_scoped_plan_limit_not_exceeded
     scope_relation = self.public_send(limit_scope) # rubocop:disable GitlabSecurity/PublicSend
     return unless scope_relation
     return if limit_feature_flag && ::Feature.disabled?(limit_feature_flag, scope_relation, default_enabled: :yaml)
+    return if limit_feature_flag_for_override && ::Feature.enabled?(limit_feature_flag_for_override, scope_relation, default_enabled: :yaml)
 
     relation = limit_relation ? self.public_send(limit_relation) : self.class.where(limit_scope => scope_relation) # rubocop:disable GitlabSecurity/PublicSend
     limits = scope_relation.actual_limits

rubocop/cop/gitlab/mark_used_feature_flags.rb

@@ -32,6 +32,7 @@ class MarkUsedFeatureFlags < RuboCop::Cop::Cop
         SELF_METHODS = %i[
           push_frontend_feature_flag
           limit_feature_flag=
+          limit_feature_flag_for_override=
         ].freeze + EXPERIMENT_METHODS + RUGGED_METHODS + WORKER_METHODS
 
         RESTRICT_ON_SEND = FEATURE_METHODS + EXPERIMENTATION_METHODS + GRAPHQL_METHODS + SELF_METHODS

spec/models/concerns/limitable_spec.rb

 # frozen_string_literal: true
 
-require 'fast_spec_helper'
-require 'active_model'
+require 'spec_helper'
 
 RSpec.describe Limitable do
   let(:minimal_test_class) do
@@ -17,7 +16,7 @@ def self.name
   end
 
   before do
-    stub_const("MinimalTestClass", minimal_test_class)
+    stub_const('MinimalTestClass', minimal_test_class)
   end
 
   it { expect(MinimalTestClass.limit_name).to eq('test_classes') }
@@ -37,25 +36,50 @@ def self.name
       instance.valid?(:create)
     end
 
-    context 'with custom relation' do
-      before do
-        MinimalTestClass.limit_relation = :custom_relation
+    context 'with custom relation and feature flags' do
+      using RSpec::Parameterized::TableSyntax
+
+      where(:limit_feature_flag, :limit_feature_flag_value, :limit_feature_flag_for_override, :limit_feature_flag_override_value, :expect_limit_applied?) do
+        nil                | nil   | nil                        | nil   | true
+        :some_feature_flag | false | nil                        | nil   | false
+        :some_feature_flag | true  | nil                        | nil   | true
+        :some_feature_flag | true  | :some_feature_flag_disable | false | true
+        :some_feature_flag | false | :some_feature_flag_disable | false | false
+        :some_feature_flag | false | :some_feature_flag_disable | true  | false
+        :some_feature_flag | true  | :some_feature_flag_disable | true  | false
       end
 
-      it 'triggers custom limit_relation' do
-        instance = MinimalTestClass.new
+      with_them do
+        let(:instance) { MinimalTestClass.new }
 
-        def instance.project
-          @project ||= Object.new
-        end
+        before do
+          def instance.project
+            @project ||= stub_feature_flag_gate('CustomActor')
+          end
+
+          stub_feature_flags("#{limit_feature_flag}": limit_feature_flag_value ? [instance.project] : false) if limit_feature_flag
+          stub_feature_flags("#{limit_feature_flag_for_override}": limit_feature_flag_override_value ? [instance.project] : false) if limit_feature_flag_for_override
+          skip_feature_flags_yaml_validation
+          skip_default_enabled_yaml_check
 
-        limits = Object.new
-        custom_relation = Object.new
-        expect(instance).to receive(:custom_relation).and_return(custom_relation)
-        expect(instance.project).to receive(:actual_limits).and_return(limits)
-        expect(limits).to receive(:exceeded?).with(instance.class.name.demodulize.tableize, custom_relation).and_return(false)
+          MinimalTestClass.limit_relation = :custom_relation
+          MinimalTestClass.limit_feature_flag = limit_feature_flag
+          MinimalTestClass.limit_feature_flag_for_override = limit_feature_flag_for_override
+        end
 
-        instance.valid?(:create)
+        it 'acts according to the feature flag settings' do
+          limits = Object.new
+          custom_relation = Object.new
+          if expect_limit_applied?
+            expect(instance).to receive(:custom_relation).and_return(custom_relation)
+            expect(instance.project).to receive(:actual_limits).and_return(limits)
+            expect(limits).to receive(:exceeded?).with(instance.class.name.demodulize.tableize, custom_relation).and_return(false)
+          else
+            expect(instance).not_to receive(:custom_relation)
+          end
+
+          instance.valid?(:create)
+        end
       end
     end
   end

spec/rubocop/cop/gitlab/mark_used_feature_flags_spec.rb

@@ -194,6 +194,10 @@ class Foo < ApplicationRecord
     include_examples 'sets flag as used', 'self.limit_feature_flag = :foo', 'foo'
   end
 
+  describe 'self.limit_feature_flag_for_override = :foo' do
+    include_examples 'sets flag as used', 'self.limit_feature_flag_for_override = :foo', 'foo'
+  end
+
   describe 'FEATURE_FLAG = :foo' do
     include_examples 'sets flag as used', 'FEATURE_FLAG = :foo', 'foo'
   end