Force reload_dirs to be a list (#978)

* Add failing test

* Force reload_dirs to be a list

* Lint

Author: euri10

tests/test_config.py

@@ -64,6 +64,11 @@ def test_config_should_reload_is_set(app, expected_should_reload):
     assert config_reload.should_reload is expected_should_reload
 
 
+def test_reload_dir_is_set():
+    config = Config(app=asgi_app, reload=True, reload_dirs="reload_me")
+    assert config.reload_dirs == ["reload_me"]
+
+
 def test_wsgi_app():
     config = Config(app=wsgi_app, interface="wsgi", proxy_headers=False)
     config.load()

uvicorn/config.py

@@ -207,7 +207,10 @@ def __init__(
         if reload_dirs is None:
             self.reload_dirs = [os.getcwd()]
         else:
-            self.reload_dirs = reload_dirs
+            if isinstance(reload_dirs, str):
+                self.reload_dirs = [reload_dirs]
+            else:
+                self.reload_dirs = reload_dirs
 
         if env_file is not None:
             from dotenv import load_dotenv