Make QA maintainer mandatory if MR is only QA and author is an SET

Signed-off-by: Rémy Coutable <remy@rymai.me>

danger/roulette/Dangerfile

@@ -39,6 +39,10 @@ MARKDOWN
 OPTIONAL_REVIEW_TEMPLATE = "%{role} review is optional for %{category}".freeze
 NOT_AVAILABLE_TEMPLATE = 'No %{role} available'.freeze
 
+def mr_author
+  roulette.team.find { |person| person.username == gitlab.mr_author }
+end
+
 def note_for_category_role(spin, role)
   if spin.optional_role == role
     return OPTIONAL_REVIEW_TEMPLATE % { role: role.capitalize, category: helper.label_for_category(spin.category) }
@@ -68,7 +72,16 @@ if changes.any?
   branch_name = gitlab.mr_json['source_branch']
 
   roulette_spins = roulette.spin(project, categories, branch_name)
-  rows = roulette_spins.map { |spin| markdown_row_for_spin(spin) }
+  rows = roulette_spins.map do |spin|
+    # MR includes QA changes, but also other changes, and author isn't an SET
+    if spin.category == :qa && categories.size > 1 && !mr_author.reviewer?(project, spin.category, [])
+      spin.optional_role = :maintainer
+    end
+
+    spin.optional_role = :maintainer if spin.category == :test
+
+    markdown_row_for_spin(spin)
+  end
 
   unknown = changes.fetch(:unknown, [])
 

lib/gitlab/danger/roulette.rb

@@ -6,7 +6,6 @@ module Gitlab
   module Danger
     module Roulette
       ROULETTE_DATA_URL = 'https://gitlab-org.gitlab.io/gitlab-roulette/roulette.json'
-      OPTIONAL_CATEGORIES = [:qa, :test].freeze
 
       Spin = Struct.new(:category, :reviewer, :maintainer, :optional_role)
 
@@ -119,11 +118,7 @@ module Gitlab
         reviewer = spin_for_person(reviewers + traintainers + traintainers, random: random)
         maintainer = spin_for_person(maintainers, random: random)
 
-        Spin.new(category, reviewer, maintainer).tap do |spin|
-          if OPTIONAL_CATEGORIES.include?(category)
-            spin.optional_role = :maintainer
-          end
-        end
+        Spin.new(category, reviewer, maintainer)
       end
     end
   end

spec/lib/gitlab/danger/roulette_spec.rb

@@ -155,8 +155,8 @@ RSpec.describe Gitlab::Danger::Roulette do
     context 'when change contains QA category' do
       let(:categories) { [:qa] }
 
-      it 'assigns QA reviewer and sets optional QA maintainer' do
-        expect(spins).to contain_exactly(matching_spin(:qa, reviewer: software_engineer_in_test, optional: :maintainer))
+      it 'assigns QA reviewer' do
+        expect(spins).to contain_exactly(matching_spin(:qa, reviewer: software_engineer_in_test))
       end
     end
 
@@ -171,8 +171,8 @@ RSpec.describe Gitlab::Danger::Roulette do
     context 'when change contains test category' do
       let(:categories) { [:test] }
 
-      it 'assigns corresponding SET and sets optional test maintainer' do
-        expect(spins).to contain_exactly(matching_spin(:test, reviewer: software_engineer_in_test, optional: :maintainer))
+      it 'assigns corresponding SET' do
+        expect(spins).to contain_exactly(matching_spin(:test, reviewer: software_engineer_in_test))
       end
     end
   end