Fix #2937: Ensure the consistency in load_dotenv's return type

flask/cli.py

@@ -594,10 +594,14 @@ def load_dotenv(path=None):
                 ' * Tip: There are .env or .flaskenv files present.'
                 ' Do "pip install python-dotenv" to use them.',
                 fg='yellow')
-        return
+        return False
 
+    # if the given path specifies the actual file then return True,
+    # else False
     if path is not None:
+        if os.path.isfile(path):
             return dotenv.load_dotenv(path)
+        return False
 
     new_dir = None
 

tests/test_cli.py

@@ -493,6 +493,10 @@ def test_load_dotenv(monkeypatch):
     # set manually, files don't overwrite
     assert os.environ['EGGS'] == '3'
 
+    # Non existent file should not load
+    file_loaded = load_dotenv('non-existent-file')
+    assert file_loaded == False
+
 
 @need_dotenv
 def test_dotenv_path(monkeypatch):