Override to specify that we're overriding

ee/app/controllers/ee/projects/git_http_controller.rb

 module EE
   module Projects
     module GitHttpController
-      def render_ok
-        raise NotImplementedError.new unless defined?(super)
+      extend ::Gitlab::Utils::Override
 
+      override :render_ok
+      def render_ok
         set_workhorse_internal_api_content_type
         render json: ::Gitlab::Workhorse.git_http_ok(repository, wiki?, user, action_name, show_all_refs: geo_request?)
       end
@@ -18,17 +19,15 @@ module EE
         authentication_result.geo?(project)
       end
 
+      override :access_actor
       def access_actor
-        raise NotImplementedError.new unless defined?(super)
-
         return :geo if geo?
 
         super
       end
 
+      override :authenticate_user
       def authenticate_user
-        raise NotImplementedError.new unless defined?(super)
-
         return super unless geo_request?
 
         payload = ::Gitlab::Geo::JwtRequestDecoder.new(request.headers['Authorization']).decode

lib/gitlab/utils/override.rb

+module Gitlab
+  module Utils
+    module Override
+      # Instead of writing patterns like this:
+      #
+      #     def f
+      #       raise NotImplementedError unless defined?(super)
+      #
+      #       true
+      #     end
+      #
+      # We could write it like:
+      #
+      #     include ::Gitlab::Utils::Override
+      #
+      #     override :f
+      #     def f
+      #       true
+      #     end
+      #
+      # This would make sure we're overriding something. See:
+      # https://gitlab.com/gitlab-org/gitlab-ee/issues/1819
+      def override(method_name)
+        return unless ENV['STATIC_VERIFICATION']
+        return if instance_methods.include?(method_name)
+
+        raise NotImplementedError.new("Method #{method_name} doesn't exist")
+      end
+    end
+  end
+end

lib/tasks/dev.rake

@@ -7,4 +7,9 @@ namespace :dev do
     Rake::Task["gitlab:setup"].invoke
     Rake::Task["gitlab:shell:setup"].invoke
   end
+
+  desc "GitLab | Eager load application"
+  task load: :environment do
+    Rails.application.eager_load!
+  end
 end

scripts/static-analysis

@@ -12,9 +12,10 @@ tasks = [
   %w[bundle exec license_finder],
   %w[yarn run eslint],
   %w[bundle exec rubocop --parallel],
-  %w[scripts/lint-conflicts.sh],
   %w[bundle exec rake gettext:lint],
-  %w[scripts/lint-changelog-yaml]
+  %w[env STATIC_VERIFICATION=true bundle exec rake dev:load],
+  %w[scripts/lint-changelog-yaml],
+  %w[scripts/lint-conflicts.sh]
 ]
 
 failed_tasks = tasks.reduce({}) do |failures, task|

spec/lib/gitlab/utils/override_spec.rb

+require 'spec_helper'
+
+describe Gitlab::Utils::Override do
+  let(:base) { Struct.new(:good) }
+
+  let(:derived) do
+    Class.new(base) do
+      extend Gitlab::Utils::Override # rubocop:disable RSpec/DescribedClass
+    end
+  end
+
+  shared_examples 'good derivation' do
+    subject do
+      derived.module_eval do
+        override :good
+        def good
+          super.succ
+        end
+      end
+
+      derived
+    end
+  end
+
+  shared_examples 'bad derivation' do
+    subject do
+      derived.module_eval do
+        override :bad
+        def bad
+          true
+        end
+      end
+
+      derived
+    end
+  end
+
+  describe '#override' do
+    context 'when STATIC_VERIFICATION is set' do
+      before do
+        stub_env('STATIC_VERIFICATION', 'true')
+      end
+
+      it_behaves_like 'good derivation' do
+        it 'checks ok for overriding method' do
+          result = subject.new(0).good
+
+          expect(result).to eq(1)
+        end
+      end
+
+      it_behaves_like 'bad derivation' do
+        it 'raises NotImplementedError when it is not overriding anything' do
+          expect { subject }.to raise_error(NotImplementedError)
+        end
+      end
+    end
+
+    context 'when STATIC_VERIFICATION is not set' do
+      it_behaves_like 'good derivation' do
+        it 'does not complain when it is overriding anything' do
+          result = subject.new(0).good
+
+          expect(result).to eq(1)
+        end
+      end
+
+      it_behaves_like 'bad derivation' do
+        it 'does not complain when it is not overriding anything' do
+          result = subject.new(0).bad
+
+          expect(result).to eq(true)
+        end
+      end
+    end
+  end
+end