Merge branch 'sy-fix-memoization-leaks' into 'master'

Clear host memoization for metric embeds feature test

See merge request gitlab-org/gitlab!25073

lib/gitlab/metrics/dashboard/url.rb

@@ -7,6 +7,7 @@ module Gitlab
       class Url
         class << self
           include Gitlab::Utils::StrongMemoize
+
           # Matches urls for a metrics dashboard. This could be
           # either the /metrics endpoint or the /metrics_dashboard
           # endpoint.

spec/features/markdown/metrics_spec.rb

@@ -93,10 +93,20 @@ describe 'Metrics rendering', :js, :use_clean_rails_memory_store_caching, :sidek
     # Ensure we identify urls with the appropriate host.
     # Configure host to include port in app:
     Gitlab.config.gitlab[:url] = root_url.chomp('/')
+
+    clear_host_from_memoized_variables
   end
 
   def restore_host
     default_url_options[:host] = @original_default_host
     Gitlab.config.gitlab[:url] = @original_gitlab_url
+
+    clear_host_from_memoized_variables
+  end
+
+  def clear_host_from_memoized_variables
+    [:metrics_regex, :grafana_regex].each do |method_name|
+      Gitlab::Metrics::Dashboard::Url.clear_memoization(method_name)
+    end
   end
 end

spec/lib/gitlab/metrics/dashboard/url_spec.rb

@@ -3,7 +3,7 @@
 require 'spec_helper'
 
 describe Gitlab::Metrics::Dashboard::Url do
-  describe '#regex' do
+  describe '#metrics_regex' do
     let(:url) do
       Gitlab::Routing.url_helpers.metrics_namespace_project_environment_url(
         'foo',