add permission support to ChangeSet forms

adds support for permissions to change set style forms for use with valkyrie
objects.

app/forms/hyrax/forms/resource_form.rb

@@ -32,6 +32,11 @@ class ResourceForm < Hyrax::ChangeSet
 
       property :agreement_accepted, virtual: true, default: false, prepopulator: ->(_opts) { self.agreement_accepted = !model.new_record }
 
+      collection :permissions, virtual: true, default: [], prepopulator: ->(_opts) { self.permissions = Hyrax::AccessControl.for(resource: model).permissions } do
+        property :agent_name
+        property :access
+      end
+
       # virtual properties for embargo/lease;
       property :embargo_release_date, virtual: true, prepopulator: ->(_opts) { self.embargo_release_date = embargo&.embargo_release_date }
       property :visibility_after_embargo, virtual: true, prepopulator: ->(_opts) { self.visibility_after_embargo = embargo&.visibility_after_embargo }

spec/forms/hyrax/forms/resource_form_spec.rb

@@ -117,6 +117,28 @@
     end
   end
 
+  describe '#permissions' do
+    it 'for a new object has empty permissions' do
+      expect(form.permissions).to be_empty
+    end
+
+    it 'for a new object prepopulates with empty permissions' do
+      expect { form.prepopulate! }
+        .not_to change { form.permissions }
+        .from(be_empty)
+    end
+
+    context 'with existing permissions' do
+      let(:work) { FactoryBot.valkyrie_create(:hyrax_work, :public) }
+
+      it 'prepopulates with the work permissions' do
+        expect { form.prepopulate! }
+          .to change { form.permissions }
+          .to contain_exactly(have_attributes(agent: 'group/public', mode: :read))
+      end
+    end
+  end
+
   describe '#human_readable_type' do
     it 'delegates to model' do
       expect(form.human_readable_type).to eq work.human_readable_type