improve end hold controller code coverage

spec/controllers/tasks/end_hold_controller_spec.rb

@@ -34,11 +34,24 @@
     context "with a non-existent parent_id" do
       let(:parent_id) { parent.id + 999 }
 
-      it "returns an error" do
+      it "returns a not found error" do
         subject
 
         expect(response.status).to eq(404)
       end
     end
+
+    context "when the user is missing" do
+      before do
+        user.destroy!
+      end
+
+      it "returns an invalid record error" do
+        subject
+
+        expect(response.status).to eq(400)
+        expect(JSON.parse(response.body)["errors"][0]["title"]).to eq "Record is invalid"
+      end
+    end
   end
 end