Fix refreshing of issues/MR count caches

This ensures the open issues/MR count caches are refreshed properly when
creating new issues or MRs. This MR also includes a change to the cache
keys to ensure all caches are rebuilt on the fly.

This particular problem was not caught in the test suite due to a null
cache being used, resulting in all calls that would use a cache using
the underlying data directly. In production the code would fail because
a newly saved record returns an empty hash in #changes meaning checks
such as `state_changed? || confidential_changed?` would return false for
new rows, thus never updating the counters.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/38061

app/models/issue.rb

@@ -275,8 +275,6 @@ class Issue < ActiveRecord::Base
   end
   def update_project_counter_caches
-    return unless update_project_counter_caches?
-
     Projects::OpenIssuesCountService.new(project).refresh_cache
   end

app/models/merge_request.rb

@@ -958,8 +958,6 @@ class MergeRequest < ActiveRecord::Base
   end
   def update_project_counter_caches
-    return unless update_project_counter_caches?
-
     Projects::OpenMergeRequestsCountService.new(target_project).refresh_cache
   end

app/services/issuable_base_service.rb

@@ -182,6 +182,7 @@ class IssuableBaseService < BaseService
       after_create(issuable)
       execute_hooks(issuable)
       invalidate_cache_counts(issuable, users: issuable.assignees)
+      issuable.update_project_counter_caches
     end
     issuable
@@ -193,8 +194,6 @@ class IssuableBaseService < BaseService
   def after_create(issuable)
     # To be overridden by subclasses
-
-    issuable.update_project_counter_caches
   end
   def before_update(issuable)
@@ -203,8 +202,6 @@ class IssuableBaseService < BaseService
   def after_update(issuable)
     # To be overridden by subclasses
-
-    issuable.update_project_counter_caches
   end
   def update(issuable)
@@ -229,6 +226,10 @@ class IssuableBaseService < BaseService
       before_update(issuable)
+      # We have to perform this check before saving the issuable as Rails resets
+      # the changed fields upon calling #save.
+      update_project_counters = issuable.update_project_counter_caches?
+
       if issuable.with_transaction_returning_status { issuable.save }
         # We do not touch as it will affect a update on updated_at field
         ActiveRecord::Base.no_touching do
@@ -249,6 +250,8 @@ class IssuableBaseService < BaseService
         after_update(issuable)
         issuable.create_new_cross_references!(current_user)
         execute_hooks(issuable, 'update')
+
+        issuable.update_project_counter_caches if update_project_counters
       end
     end

app/services/issues/close_service.rb

@@ -29,6 +29,7 @@ module Issues
         todo_service.close_issue(issue, current_user)
         execute_hooks(issue, 'close')
         invalidate_cache_counts(issue, users: issue.assignees)
+        issue.update_project_counter_caches
       end
       issue

app/services/merge_requests/close_service.rb

@@ -14,6 +14,7 @@ module MergeRequests
         todo_service.close_merge_request(merge_request, current_user)
         execute_hooks(merge_request, 'close')
         invalidate_cache_counts(merge_request, users: merge_request.assignees)
+        merge_request.update_project_counter_caches
       end
       merge_request

app/services/projects/count_service.rb

@@ -2,6 +2,11 @@ module Projects
   # Base class for the various service classes that count project data (e.g.
   # issues or forks).
   class CountService
+    # The version of the cache format. This should be bumped whenever the
+    # underlying logic changes. This removes the need for explicitly flushing
+    # all caches.
+    VERSION = 1
+
     def initialize(project)
       @project = project
     end
@@ -37,7 +42,7 @@ module Projects
     end
     def cache_key
-      ['projects', @project.id, cache_key_name]
+      ['projects', 'count_service', VERSION, @project.id, cache_key_name]
     end
   end
 end

spec/services/issues/close_service_spec.rb

@@ -42,7 +42,7 @@ describe Issues::CloseService do
       service.execute(issue)
     end
-    it 'refreshes the number of open issues' do
+    it 'refreshes the number of open issues', :use_clean_rails_memory_store_caching do
       expect { service.execute(issue) }
         .to change { project.open_issues_count }.from(1).to(0)
     end

spec/services/issues/create_service_spec.rb

@@ -35,7 +35,7 @@ describe Issues::CreateService do
         expect(issue.due_date).to eq Date.tomorrow
       end
-      it 'refreshes the number of open issues' do
+      it 'refreshes the number of open issues', :use_clean_rails_memory_store_caching do
         expect { issue }.to change { project.open_issues_count }.from(0).to(1)
       end

spec/services/issues/update_service_spec.rb

@@ -64,6 +64,13 @@ describe Issues::UpdateService, :mailer do
         expect(issue.due_date).to eq Date.tomorrow
       end
+      it 'refreshes the number of open issues when the issue is made confidential', :use_clean_rails_memory_store_caching do
+        issue # make sure the issue is created first so our counts are correct.
+
+        expect { update_issue(confidential: true) }
+          .to change { project.open_issues_count }.from(1).to(0)
+      end
+
       it 'updates open issue counter for assignees when issue is reassigned' do
         update_issue(assignee_ids: [user2.id])

spec/services/merge_requests/close_service_spec.rb

@@ -52,7 +52,7 @@ describe MergeRequests::CloseService do
       end
     end
-    it 'refreshes the number of open merge requests for a valid MR' do
+    it 'refreshes the number of open merge requests for a valid MR', :use_clean_rails_memory_store_caching do
       service = described_class.new(project, user, {})
       expect { service.execute(merge_request) }

spec/services/merge_requests/create_service_spec.rb

@@ -37,7 +37,7 @@ describe MergeRequests::CreateService do
         expect(service).to have_received(:execute_hooks).with(merge_request)
       end
-      it 'refreshes the number of open merge requests' do
+      it 'refreshes the number of open merge requests', :use_clean_rails_memory_store_caching do
         expect { service.execute }
           .to change { project.open_merge_requests_count }.from(0).to(1)
       end

spec/services/projects/count_service_spec.rb

@@ -66,8 +66,8 @@ describe Projects::CountService do
   describe '#cache_key' do
     it 'returns the cache key as an Array' do
-      allow(service).to receive(:cache_key_name).and_return('count_service')
-      expect(service.cache_key).to eq(['projects', 1, 'count_service'])
+      allow(service).to receive(:cache_key_name).and_return('foo')
+      expect(service.cache_key).to eq(['projects', 'count_service', described_class::VERSION, 1, 'foo'])
     end
   end
 end