mypy: Fix several Optional typing errors.

zerver/lib/actions.py

@@ -1937,7 +1937,7 @@ def do_change_default_sending_stream(user_profile, stream, log=True):
                    'stream': str(stream)})
     if user_profile.is_bot:
         if stream:
-            stream_name = stream.name
+            stream_name = stream.name  # type: Optional[Text]
         else:
             stream_name = None
         send_event(dict(type='realm_bot',
@@ -1960,7 +1960,7 @@ def do_change_default_events_register_stream(user_profile, stream, log=True):
                    'stream': str(stream)})
     if user_profile.is_bot:
         if stream:
-            stream_name = stream.name
+            stream_name = stream.name  # type: Optional[Text]
         else:
             stream_name = None
         send_event(dict(type='realm_bot',

zerver/lib/create_user.py

@@ -26,7 +26,7 @@ def random_api_key():
 # Recipient objects
 def create_user_profile(realm, email, password, active, bot_type, full_name,
                         short_name, bot_owner, is_mirror_dummy, tos_version):
-    # type: (Realm, Text, Text, bool, Optional[int], Text, Text, Optional[UserProfile], bool, Optional[Text]) -> UserProfile
+    # type: (Realm, Text, Optional[Text], bool, Optional[int], Text, Text, Optional[UserProfile], bool, Optional[Text]) -> UserProfile
     now = timezone.now()
     email = UserManager.normalize_email(email)
 

zerver/lib/db.py

@@ -13,7 +13,7 @@ ParamsT = Union[Iterable[Any], Mapping[Text, Any]]
 # Similar to the tracking done in Django's CursorDebugWrapper, but done at the
 # psycopg2 cursor level so it works with SQLAlchemy.
 def wrapper_execute(self, action, sql, params=()):
-    # type: (CursorObj, Callable[[NonBinaryStr, Optional[ParamsT]], CursorObj], NonBinaryStr, ParamsT) -> CursorObj
+    # type: (CursorObj, Callable[[NonBinaryStr, Optional[ParamsT]], CursorObj], NonBinaryStr, Optional[ParamsT]) -> CursorObj
     start = time.time()
     try:
         return action(sql, params)

zerver/lib/debug.py

@@ -14,7 +14,7 @@ from typing import Optional
 # setup, which we might want if we move Tornado to run in a daemon
 # rather than via screen).
 def interactive_debug(sig, frame):
-    # type: (int, Optional[FrameType]) -> None
+    # type: (int, FrameType) -> None
     """Interrupt running process, and provide a python prompt for
     interactive debugging."""
     d = {'_frame': frame}      # Allow access to frame object.

zerver/lib/test_fixtures.py

@@ -83,11 +83,11 @@ def _check_hash(target_hash_file, **options):
     with open(target_hash_file) as f:
         target_hash_content = hashlib.sha1(f.read().encode('utf8')).hexdigest()
 
-    if os.path.exists(source_hash_file):
+    if not os.path.exists(source_hash_file):
+        source_hash_content = None
+    else:
         with open(source_hash_file) as f:
             source_hash_content = f.read().strip()
-    else:
-        source_hash_content = None
 
     with open(source_hash_file, 'w') as f:
         f.write(target_hash_content)
@@ -99,7 +99,7 @@ def is_template_database_current(
         migration_status='var/migration-status',
         settings='zproject.test_settings',
         check_files=None):
-    # type: (Optional[Text], Optional[Text], Optional[Text], Optional[List[str]]) -> bool
+    # type: (Text, Text, Text, Optional[List[str]]) -> bool
     # Using str type for check_files because re.split doesn't accept unicode
     if check_files is None:
         check_files = [

zerver/lib/test_helpers.py

@@ -104,14 +104,14 @@ def simulated_empty_cache():
     cache_queries = [] # type: List[Tuple[str, Union[Text, List[Text]], Text]]
 
     def my_cache_get(key, cache_name=None):
-        # type: (Text, Optional[str]) -> Any
+        # type: (Text, Optional[str]) -> Optional[Dict[Text, Any]]
         cache_queries.append(('get', key, cache_name))
         return None
 
     def my_cache_get_many(keys, cache_name=None):
         # type: (List[Text], Optional[str]) -> Dict[Text, Any]
         cache_queries.append(('getmany', keys, cache_name))
-        return None
+        return {}
 
     old_get = cache.cache_get
     old_get_many = cache.cache_get_many

zerver/lib/validator.py

@@ -111,7 +111,7 @@ def check_variable_type(allowed_type_funcs):
     types for this variable.
     """
     def enumerated_type_check(var_name, val):
-        # type: (str, Any) -> str
+        # type: (str, Any) -> Optional[str]
         for func in allowed_type_funcs:
             if not func(var_name, val):
                 return None

zerver/logging_handlers.py

@@ -1,6 +1,7 @@
 from __future__ import absolute_import
 
 from django.conf import settings
+from typing import Optional
 
 import logging
 import traceback
@@ -32,7 +33,7 @@ class AdminZulipHandler(logging.Handler):
             exception_filter = get_exception_reporter_filter(request)
 
             if record.exc_info:
-                stack_trace = ''.join(traceback.format_exception(*record.exc_info))
+                stack_trace = ''.join(traceback.format_exception(*record.exc_info))  # type: Optional[str]
             else:
                 stack_trace = None
 

zerver/middleware.py

@@ -107,7 +107,7 @@ def write_log_line(log_data, path, method, remote_ip, email, client_name,
     if error_content is not None:
         error_content_iter = (error_content,)
 
-# For statsd timer name
+    # For statsd timer name
     if path == '/':
         statsd_path = u'webreq'
     else:
@@ -217,6 +217,7 @@ def write_log_line(log_data, path, method, remote_ip, email, client_name,
 
     # Log some additional data whenever we return certain 40x errors
     if 400 <= status_code < 500 and status_code not in [401, 404, 405]:
+        assert error_content_iter is not None
         error_content_list = list(error_content_iter)
         if error_content_list:
             error_data = u''

zerver/views/realm_emoji.py

@@ -18,7 +18,7 @@ def list_emoji(request, user_profile):
     return json_success({'emoji': user_profile.realm.get_emoji()})
 
 @has_request_variables
-def upload_emoji(request, user_profile, emoji_name=None, url=REQ()):
+def upload_emoji(request, user_profile, emoji_name, url=REQ()):
     # type: (HttpRequest, UserProfile, Text, Text) -> HttpResponse
     check_valid_emoji_name(emoji_name)
     check_emoji_admin(user_profile)