Add GroupSharedRunnersSettingUpdate request spec

spec/requests/api/graphql/mutations/groups/update_shared_runners_setting_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'GroupSharedRunnersSettingUpdate' do
+  include GraphqlHelpers
+
+  let_it_be(:user) { create(:user) }
+  let_it_be_with_reload(:group) { create(:group) }
+
+  let(:variables) do
+    {
+      full_path: group.full_path,
+      shared_runners_setting: 'DISABLED_WITH_OVERRIDE'
+    }
+  end
+
+  let(:mutation) { graphql_mutation(:group_shared_runners_setting_update, variables) }
+
+  context 'when unauthorized' do
+    shared_examples 'unauthorized' do
+      it 'returns an error' do
+        post_graphql_mutation(mutation, current_user: user)
+
+        expect(graphql_errors).not_to be_empty
+      end
+    end
+
+    context 'when not a group member' do
+      it_behaves_like 'unauthorized'
+    end
+
+    context 'when a non-admin group member' do
+      before do
+        group.add_developer(user)
+      end
+
+      it_behaves_like 'unauthorized'
+    end
+  end
+
+  context 'when authorized' do
+    before do
+      group.add_owner(user)
+    end
+
+    it 'updates shared runners settings' do
+      post_graphql_mutation(mutation, current_user: user)
+
+      expect(response).to have_gitlab_http_status(:success)
+      expect(graphql_errors).to be_nil
+      expect(group.reload.shared_runners_setting).to eq(variables[:shared_runners_setting].downcase)
+    end
+
+    context 'when bad arguments are provided' do
+      let(:variables) { { full_path: '', shared_runners_setting: 'INVALID' } }
+
+      it 'returns the errors' do
+        post_graphql_mutation(mutation, current_user: user)
+
+        expect(graphql_errors).not_to be_empty
+        expect(group.reload.shared_runners_setting).to eq('enabled')
+      end
+    end
+  end
+end