add tests

tests/test_logging.py

@@ -1,5 +1,7 @@
-import asyncio
 import uuid
+from importlib import reload
+
+from sanic.config import LOGGING
 from sanic.response import text
 from sanic import Sanic
 from io import StringIO
@@ -10,6 +12,11 @@ function: %(funcName)s(); \
 message: %(message)s'''
 
 
+def reset_logging():
+    logging.shutdown()
+    reload(logging)
+
+
 def test_log():
     log_stream = StringIO()
     for handler in logging.root.handlers[:]:
@@ -32,5 +39,19 @@ def test_log():
     log_text = log_stream.getvalue()
     assert rand_string in log_text
 
+
+def test_default_log_fmt():
+
+    reset_logging()
+    Sanic()
+    for fmt in [h.formatter for h in logging.getLogger('sanic').handlers]:
+        assert fmt._fmt == LOGGING['formatters']['simple']['format']
+
+    reset_logging()
+    Sanic(log_config=None)
+    for fmt in [h.formatter for h in logging.getLogger('sanic').handlers]:
+        assert fmt._fmt == "%(asctime)s: %(levelname)s: %(message)s"
+
+
 if __name__ == "__main__":
     test_log()