Add event tracking to NPM package API

Add event tracking for pushing and pulling
npm packages via the api endpoints.

ee/lib/api/npm_packages.rb

@@ -144,6 +144,8 @@ module API
         package_file = ::Packages::PackageFileFinder
           .new(package, params[:file_name]).execute!
 
+        track_event('pull_package')
+
         present_carrierwave_file!(package_file.file)
       end
 
@@ -158,6 +160,8 @@ module API
       put ':id/packages/npm/:package_name', requirements: NPM_ENDPOINT_REQUIREMENTS do
         authorize_create_package!(user_project)
 
+        track_event('push_package')
+
         created_package = ::Packages::Npm::CreatePackageService
           .new(user_project, current_user, params.merge(build: current_authenticated_job)).execute
 

ee/spec/requests/api/npm_packages_spec.rb

@@ -133,12 +133,16 @@ describe API::NpmPackages do
     end
 
     context 'a public project' do
+      subject { get_file(package_file) }
+
       it 'returns the file with no token needed' do
-        get_file(package_file)
+        subject
 
         expect(response).to have_gitlab_http_status(200)
         expect(response.content_type.to_s).to eq('application/octet-stream')
       end
+
+      it_behaves_like 'a gitlab tracking event', described_class.name, 'pull_package'
     end
 
     context 'private project' do
@@ -230,14 +234,20 @@ describe API::NpmPackages do
         let(:package_name) { "@#{group.path}/my_package_name" }
         let(:params) { upload_params(package_name) }
 
-        it 'creates npm package with file with access token' do
-          expect { upload_package_with_token(package_name, params) }
+        context 'with access token' do
+          subject { upload_package_with_token(package_name, params) }
+
+          it_behaves_like 'a gitlab tracking event', described_class.name, 'push_package'
+
+          it 'creates npm package with file' do
+            expect { subject }
               .to change { project.packages.count }.by(1)
               .and change { Packages::PackageFile.count }.by(1)
               .and change { Packages::Tag.count }.by(1)
 
             expect(response).to have_gitlab_http_status(200)
           end
+        end
 
         it 'creates npm package with file with job token' do
           expect { upload_package_with_job_token(package_name, params) }