Smarter flushing of branch statistics caches

Instead of flushing the behind/ahead counts for all branches upon every
push we now only flush the cache of branches that actually need to have
these statistics recalculated. There are now basically 2 scenarios and
their effects:

1. A user pushes a commit to the default branch, this results in the
   cache being flushed for all branches.
2. A user pushes to a non default branch, this results in _only_ the
   cache for that branch being flushed.

The existing code (Repository#expire_cache) remains backwards compatible
with the previous behaviour, the new behaviour is only applied when a
branch name is passed as an argument. This ensures that when for example
a project is deleted the cache for all branches is flushed.

1 files changed, 3 insertions, 3 deletions

diff --git a/spec/services/git_push_service_spec.rb b/spec/services/git_push_service_spec.rb
index 349809743c7..eb3a5fe43f5 100644
--- a/spec/services/git_push_service_spec.rb
+++ b/spec/services/git_push_service_spec.rb
@@ -23,7 +23,7 @@ describe GitPushService, services: true do
       it { is_expected.to be_truthy }
 
       it 'flushes general cached data' do
-        expect(project.repository).to receive(:expire_cache)
+        expect(project.repository).to receive(:expire_cache).with('master')
 
         subject
       end
@@ -43,7 +43,7 @@ describe GitPushService, services: true do
       it { is_expected.to be_truthy }
 
       it 'flushes general cached data' do
-        expect(project.repository).to receive(:expire_cache)
+        expect(project.repository).to receive(:expire_cache).with('master')
 
         subject
       end
@@ -63,7 +63,7 @@ describe GitPushService, services: true do
       end
 
       it 'flushes general cached data' do
-        expect(project.repository).to receive(:expire_cache)
+        expect(project.repository).to receive(:expire_cache).with('master')
 
         subject
       end