Merge branch 'update_main_lang_if_unset' into 'master'

Only update main language if it is not already set

Related to gitlab-org/gitlab-ce#14937 (but does not fully fix) This is a temporary fix so performance isn't affected so much. 

cc @yorickpeterse @ayufan how does this look?

See merge request !3556

1 files changed, 21 insertions, 5 deletions

diff --git a/spec/services/git_push_service_spec.rb b/spec/services/git_push_service_spec.rb
index 1047e32960e..b40a5c1c818 100644
--- a/spec/services/git_push_service_spec.rb
+++ b/spec/services/git_push_service_spec.rb
@@ -164,21 +164,37 @@ describe GitPushService, services: true do
     end
 
     context "after push" do
-      before do
-        @service = execute_service(project, user, @oldrev, @newrev, ref)
+      def execute
+        execute_service(project, user, @oldrev, @newrev, ref)
       end
 
       context "to master" do
         let(:ref) { @ref }
 
-        it { expect(@service.update_main_language).to eq(true) }
-        it { expect(project.main_language).to eq("Ruby") }
+        context 'when main_language is nil' do
+          it 'obtains the language from the repository' do
+            expect(project.repository).to receive(:main_language)
+            execute
+          end
+
+          it 'sets the project main language' do
+            execute
+            expect(project.main_language).to eq("Ruby")
+          end
+        end
+
+        context 'when main_language is already set' do
+          it 'does not check the repository' do
+            execute # do an initial run to simulate lang being preset
+            expect(project.repository).not_to receive(:main_language)
+            execute
+          end
+        end
       end
 
       context "to other branch" do
         let(:ref) { 'refs/heads/feature/branch' }
 
-        it { expect(@service.update_main_language).to eq(nil) }
         it { expect(project.main_language).to eq(nil) }
       end
     end