From ab98775bd273f6ea5718acd6820caffe4a09fba5 Mon Sep 17 00:00:00 2001
From: lynskylate <lynskylate@gmail.com>
Date: Fri, 9 Aug 2019 21:12:36 +0800
Subject: [PATCH] Optimize error info

---
 vm/src/obj/objbool.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/vm/src/obj/objbool.rs b/vm/src/obj/objbool.rs
index a8588d391..6988028ea 100644
--- a/vm/src/obj/objbool.rs
+++ b/vm/src/obj/objbool.rs
@@ -31,7 +31,12 @@ pub fn boolval(vm: &VirtualMachine, obj: PyObjectRef) -> PyResult<bool> {
             let bool_obj = vm.invoke(method, PyFuncArgs::default())?;
             match bool_obj.payload::<PyInt>() {
                 Some(int_obj) => !int_obj.as_bigint().is_zero(),
-                None => return Err(vm.new_type_error(String::from(""))),
+                None => {
+                    return Err(vm.new_type_error(format!(
+                        "__bool__ should return bool, returned type {}",
+                        bool_obj.class().name
+                    )))
+                }
             }
         }
         None => match vm.get_method(obj.clone(), "__len__") {