run_single_user improvements

locust/debug.py

@@ -2,6 +2,7 @@
 import os
 import inspect
 import locust
+import locust.log
 from locust import User, argument_parser
 from typing import Type, Optional
 from locust.env import Environment
@@ -102,7 +103,7 @@ def run_single_user(
     include_time=False,
     include_context=False,
     include_payload=False,
-    loglevel=None,
+    loglevel: Optional[str] = "WARNING",
 ):
     """
     Runs a single User. Useful when you want to run a debugger.
@@ -113,8 +114,8 @@ def run_single_user(
 
     It prints some info about every request to stdout, and you can get additional info using the `include_*` flags
 
-    By default, it does not set up locusts logging system (because it could interfere with the printing of requests),
-    but you can change that by passing a log level (e.g. *loglevel="INFO"*)
+    It also initiates logging on WARNING level (not INFO, because it could interfere with the printing of requests),
+    but you can change that by passing a log level (or disabling logging entirely by passing None)
     """
     global _env
 
@@ -141,6 +142,9 @@ def run_single_user(
         )
         # fire various events (quit and test_stop will never get called, sorry about that)
         _env.events.init.fire(environment=_env, runner=None, web_ui=None)
+        # uncaught events will be suppressed, so check if that happened
+        if locust.log.unhandled_greenlet_exception:
+            raise Exception("Unhandled exception in init")
 
     # do the things that the Runner usually does
     _env.user_classes = [user_class]

locust/test/test_debugging.py

@@ -23,7 +23,7 @@ def test_run_single_user_pass_host_to_user_classes(self):
 
         class MyUser1(HttpUser):
             @task
-            def my_task():
+            def my_task(self):
                 pass
 
         def _stop_user():
@@ -34,4 +34,7 @@ def _stop_user():
         t = Timer(1, _stop_user)
         t.start()
 
-        debug.run_single_user(MyUser1)
+        debug.run_single_user(
+            MyUser1,
+            loglevel=None,  # another log setup might mess with other tests...
+        )

locust/user/task.py

@@ -88,7 +88,7 @@ def decorator_func(func):
     Check if task was used without parentheses (not called), like this::
 
         @task
-        def my_task()
+        def my_task(self)
             pass
     """
     if callable(weight):