Add /lock and /unlock quick actions

Closes #39173

app/services/quick_actions/interpret_service.rb

@@ -489,6 +489,30 @@ module QuickActions
       "#{comment} #{TABLEFLIP}"
     end
 
+    desc "Lock the discussion"
+    explanation "Locks the discussion"
+    condition do
+      issuable.is_a?(Issuable) &&
+        issuable.persisted? &&
+        !issuable.discussion_locked? &&
+        current_user.can?(:"admin_#{issuable.to_ability_name}", issuable)
+    end
+    command :lock do
+      @updates[:discussion_locked] = true
+    end
+
+    desc "Unlock the discussion"
+    explanation "Unlocks the discussion"
+    condition do
+      issuable.is_a?(Issuable) &&
+        issuable.persisted? &&
+        issuable.discussion_locked? &&
+        current_user.can?(:"admin_#{issuable.to_ability_name}", issuable)
+    end
+    command :unlock do
+      @updates[:discussion_locked] = false
+    end
+
     # This is a dummy command, so that it appears in the autocomplete commands
     desc 'CC'
     params '@user'

changelogs/unreleased/lock-unlock-quick-actions.yml

+---
+title: Add /lock and /unlock quick actions
+merge_request: 15197
+author: Mehdi Lahmam (@mehlah)
+type: added

doc/user/project/quick_actions.md

@@ -44,3 +44,5 @@ do.
 | `/shrug`                   | Append the comment with `¯\＿(ツ)＿/¯` |
 | <code>/copy_metadata #issue &#124; !merge_request</code> | Copy labels and milestone from other issue or merge request |
 | `/confidential`            | Makes the issue confidential |
+| `/lock`                    | Lock the discussion |
+| `/unlock`                  | Unlock the discussion |

spec/services/quick_actions/interpret_service_spec.rb

@@ -272,6 +272,28 @@ describe QuickActions::InterpretService do
       end
     end
 
+    shared_examples 'lock command' do
+      let(:issue) { create(:issue, project: project, discussion_locked: false) }
+      let(:merge_request) { create(:merge_request, source_project: project, discussion_locked: false) }
+
+      it 'returns discussion_locked: true if content contains /lock' do
+        _, updates = service.execute(content, issuable)
+
+        expect(updates).to eq(discussion_locked: true)
+      end
+    end
+
+    shared_examples 'unlock command' do
+      let(:issue) { create(:issue, project: project, discussion_locked: true) }
+      let(:merge_request) { create(:merge_request, source_project: project, discussion_locked: true) }
+
+      it 'returns discussion_locked: true if content contains /unlock' do
+        _, updates = service.execute(content, issuable)
+
+        expect(updates).to eq(discussion_locked: false)
+      end
+    end
+
     shared_examples 'empty command' do
       it 'populates {} if content contains an unsupported command' do
         _, updates = service.execute(content, issuable)
@@ -786,6 +808,26 @@ describe QuickActions::InterpretService do
       let(:issuable) { issue }
     end
 
+    it_behaves_like 'lock command' do
+      let(:content) { '/lock' }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'lock command' do
+      let(:content) { '/lock' }
+      let(:issuable) { merge_request }
+    end
+
+    it_behaves_like 'unlock command' do
+      let(:content) { '/unlock' }
+      let(:issuable) { issue }
+    end
+
+    it_behaves_like 'unlock command' do
+      let(:content) { '/unlock' }
+      let(:issuable) { merge_request }
+    end
+
     context '/todo' do
       let(:content) { '/todo' }
 
@@ -961,6 +1003,16 @@ describe QuickActions::InterpretService do
         let(:content) { '/duplicate #{issue.to_reference}' }
         let(:issuable) { issue }
       end
+
+      it_behaves_like 'empty command' do
+        let(:content) { '/lock' }
+        let(:issuable) { issue }
+      end
+
+      it_behaves_like 'empty command' do
+        let(:content) { '/unlock' }
+        let(:issuable) { issue }
+      end
     end
 
     context '/award command' do

spec/support/features/issuable_slash_commands_shared_examples.rb

@@ -285,6 +285,80 @@ shared_examples 'issuable record that supports quick actions in its description
         expect(issuable.reload.assignees).to eq [maintainer]
       end
     end
+
+    context "with a note locking the #{issuable_type} discussion" do
+      before do
+        issuable.update(discussion_locked: false)
+        expect(issuable).not_to be_discussion_locked
+      end
+
+      context "when current user can lock #{issuable_type} discussion" do
+        it "locks the #{issuable_type} discussion" do
+          add_note("/lock")
+
+          expect(page).not_to have_content '/lock'
+          expect(page).to have_content 'Commands applied'
+
+          expect(issuable.reload).to be_discussion_locked
+        end
+      end
+
+      context "when current user cannot lock #{issuable_type}" do
+        before do
+          guest = create(:user)
+          project.add_guest(guest)
+
+          gitlab_sign_out
+          gitlab_sign_in(guest)
+          visit public_send("namespace_project_#{issuable_type}_path", project.namespace, project, issuable)
+        end
+
+        it "does not lock the #{issuable_type} discussion" do
+          add_note("/lock")
+
+          expect(page).not_to have_content 'Commands applied'
+
+          expect(issuable).not_to be_discussion_locked
+        end
+      end
+    end
+
+    context "with a note unlocking the #{issuable_type} discussion" do
+      before do
+        issuable.update(discussion_locked: true)
+        expect(issuable).to be_discussion_locked
+      end
+
+      context "when current user can unlock #{issuable_type} discussion" do
+        it "unlocks the #{issuable_type} discussion" do
+          add_note("/unlock")
+
+          expect(page).not_to have_content '/unlock'
+          expect(page).to have_content 'Commands applied'
+
+          expect(issuable.reload).not_to be_discussion_locked
+        end
+      end
+
+      context "when current user cannot unlock #{issuable_type}" do
+        before do
+          guest = create(:user)
+          project.add_guest(guest)
+
+          gitlab_sign_out
+          gitlab_sign_in(guest)
+          visit public_send("namespace_project_#{issuable_type}_path", project.namespace, project, issuable)
+        end
+
+        it "does not unlock the #{issuable_type} discussion" do
+          add_note("/unlock")
+
+          expect(page).not_to have_content 'Commands applied'
+
+          expect(issuable).to be_discussion_locked
+        end
+      end
+    end
   end
 
   describe "preview of note on #{issuable_type}", :js do