Add class stub in query limit helper spec

.rubocop.yml

@@ -374,7 +374,6 @@ RSpec/LeakyConstantDeclaration:
     - 'spec/services/clusters/applications/check_installation_progress_service_spec.rb'
     - 'spec/services/clusters/applications/check_uninstall_progress_service_spec.rb'
     - 'spec/support/shared_examples/quick_actions/issuable/issuable_quick_actions_shared_examples.rb'
-    - 'spec/support_specs/matchers/exceed_query_limit_helpers_spec.rb'
 
 RSpec/EmptyLineAfterHook:
   Enabled: false

changelogs/unreleased/leaky-constant-fix-3.yml

+---
+title: Add class stubs and fix leaky constant alert in query limit helper spec
+merge_request: 31949
+author: Rajendra Kadam
+type: fixed

spec/support_specs/matchers/exceed_query_limit_helpers_spec.rb

@@ -3,11 +3,15 @@
 require 'spec_helper'
 
 describe ExceedQueryLimitHelpers do
-  class TestQueries < ActiveRecord::Base
+  before do
+    stub_const('TestQueries', Class.new(ActiveRecord::Base))
+    stub_const('TestMatcher', Class.new)
+
+    TestQueries.class_eval do
       self.table_name = 'schema_migrations'
     end
 
-  class TestMatcher
+    TestMatcher.class_eval do
       include ExceedQueryLimitHelpers
 
       def expected
@@ -16,6 +20,7 @@ describe ExceedQueryLimitHelpers do
         end
       end
     end
+  end
 
   it 'does not contain marginalia annotations' do
     test_matcher = TestMatcher.new