fix: ensure referenced testcase share the same session

docs/CHANGELOG.md

@@ -1,5 +1,11 @@
 # Release History
 
+## 3.0.5 (2020-05-21)
+
+**Fixed**
+
+- fix: ensure referenced testcase share the same session
+
 ## 3.0.4 (2020-05-19)
 
 **Added**

httprunner/runner.py

@@ -68,7 +68,6 @@ class HttpRunner(object):
         parsed_request_dict["json"] = parsed_request_dict.pop("req_json", {})
 
         # request
-        self.__session = self.__session or HttpSession()
         resp = self.__session.request(method, url, **parsed_request_dict)
         resp_obj = ResponseObject(resp)
 
@@ -184,6 +183,7 @@ class HttpRunner(object):
         parse_config(self.config)
         self.__start_at = time.time()
         self.__step_datas: List[StepData] = []
+        self.__session = self.__session or HttpSession()
         self.__session_variables = {}
         for step in self.teststeps:
             # update with config variables