Fix this extension when using Flask 1.x.x

Still need to get a unit test in place so this doesn't happen again.
Refs #437

Author: vimalloc

flask_jwt_extended/view_decorators.py

@@ -119,7 +119,14 @@ def wrapper(fn):
         @wraps(fn)
         def decorator(*args, **kwargs):
             verify_jwt_in_request(optional, fresh, refresh, locations)
-            return current_app.ensure_sync(fn)(*args, **kwargs)
+
+            # Compatibility with flask < 2.0
+            try:
+                return current_app.ensure_sync(fn)(*args, **kwargs)
+            except AttributeError as e:
+                if str(e) != "'Flask' object has no attribute 'ensure_sync'":
+                    raise
+                return fn(*args, **kwargs)
 
         return decorator
 

requirements.txt

@@ -3,5 +3,6 @@ cryptography==3.4.7
 Flask==2.0.1
 Pallets-Sphinx-Themes==2.0.1
 pre-commit==2.13.0
+PyJWT==2.1.0
 Sphinx==4.0.2
 tox==3.23.1