Add annotations to avatar.py, db.py, logging_util.py, unminify.py.

Also, fixed a a small type annotation in users.py because email must
be a string because emails don't support UTF-8 at this time (according
a comment in gravatar_hash in avatar.py).

zerver/lib/avatar.py

@@ -3,8 +3,13 @@ from django.conf import settings
 
 import hashlib
 from zerver.lib.utils import make_safe_digest
+if False:
+    from zerver.models import UserProfile
+
+from six import text_type
 
 def gravatar_hash(email):
+    # type: (str) -> str
     """Compute the Gravatar hash for an email address."""
     # Non-ASCII characters aren't permitted by the currently active e-mail
     # RFCs. However, the IETF has published https://tools.ietf.org/html/rfc4952,
@@ -14,6 +19,7 @@ def gravatar_hash(email):
     return make_safe_digest(email.lower(), hashlib.md5)
 
 def user_avatar_hash(email):
+    # type: (str) -> str
     # Salting the user_key may be overkill, but it prevents us from
     # basically mimicking Gravatar's hashing scheme, which could lead
     # to some abuse scenarios like folks using us as a free Gravatar
@@ -22,12 +28,14 @@ def user_avatar_hash(email):
     return make_safe_digest(user_key, hashlib.sha1)
 
 def avatar_url(user_profile):
+    # type: (UserProfile) -> text_type
     return get_avatar_url(
             user_profile.avatar_source,
             user_profile.email
     )
 
 def get_avatar_url(avatar_source, email):
+    # type: (str, str) -> str
     if avatar_source == 'U':
         hash_key = user_avatar_hash(email)
         if settings.LOCAL_UPLOADS_DIR is not None:

zerver/lib/db.py

@@ -3,9 +3,16 @@ from __future__ import absolute_import
 import time
 from psycopg2.extensions import cursor, connection
 
+from typing import Callable, Optional, Iterable, Any, Dict, Union, TypeVar, \
+    Mapping, Sequence
+from six import text_type
+
+CursorObj = TypeVar('CursorObj', bound=cursor)
+
 # 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[[text_type, Optional[Union[Iterable[Any], Dict[text_type, Any]]]], CursorObj], text_type, Union[Iterable[Any], Dict[text_type, Any]]) -> CursorObj
     start = time.time()
     try:
         return action(sql, params)
@@ -20,25 +27,30 @@ class TimeTrackingCursor(cursor):
     """A psycopg2 cursor class that tracks the time spent executing queries."""
 
     def execute(self, query, vars=None):
+        # type: (text_type, Optional[Union[Iterable[Any], Dict[text_type, Any]]]) -> TimeTrackingCursor
         return wrapper_execute(self, super(TimeTrackingCursor, self).execute, query, vars)
 
     def executemany(self, query, vars):
+        # type: (text_type, Iterable[Any]) -> TimeTrackingCursor
         return wrapper_execute(self, super(TimeTrackingCursor, self).executemany, query, vars)
 
 class TimeTrackingConnection(connection):
     """A psycopg2 connection class that uses TimeTrackingCursors."""
 
     def __init__(self, *args, **kwargs):
+        # type: (Sequence[Any], Mapping[text_type, Any]) -> None
         self.queries = [] # type: List[Dict[str, str]]
         super(TimeTrackingConnection, self).__init__(*args, **kwargs)
 
     def cursor(self, name=None):
+        # type: (Optional[text_type]) -> TimeTrackingCursor
         if name is None:
             return super(TimeTrackingConnection, self).cursor(cursor_factory=TimeTrackingCursor)
         else:
             return super(TimeTrackingConnection, self).cursor(name, cursor_factory=TimeTrackingCursor)
 
 def reset_queries():
+    # type: () -> None
     from django.db import connections
     for conn in connections.all():
         if conn.connection is not None:

zerver/lib/logging_util.py

@@ -9,6 +9,7 @@ class _RateLimitFilter(object):
     last_error = datetime.min
 
     def filter(self, record):
+        # type: (logging.LogRecord) -> bool
         from django.conf import settings
         from django.core.cache import cache
 
@@ -44,9 +45,11 @@ class EmailLimiter(_RateLimitFilter):
 
 class ReturnTrue(logging.Filter):
     def filter(self, record):
+        # type: (logging.LogRecord) -> bool
         return True
 
 class RequireReallyDeployed(logging.Filter):
     def filter(self, record):
+        # type: (logging.LogRecord) -> bool
         from django.conf import settings
         return settings.PRODUCTION

zerver/lib/unminify.py

@@ -4,16 +4,21 @@ import re
 import os.path
 import sourcemap
 from six.moves import map
+from six import text_type
+
+from typing import Dict
 
 
 class SourceMap(object):
     '''Map (line, column) pairs from generated to source file.'''
 
     def __init__(self, sourcemap_dir):
+        # type: (text_type) -> None
         self._dir = sourcemap_dir
-        self._indices = {} # type: Dict[str, sourcemap.SourceMapDecoder]
+        self._indices = {} # type: Dict[text_type, sourcemap.SourceMapDecoder]
 
     def _index_for(self, minified_src):
+        # type: (text_type) -> sourcemap.SourceMapDecoder
         '''Return the source map index for minified_src, loading it if not
            already loaded.'''
         if minified_src not in self._indices:
@@ -23,7 +28,8 @@ class SourceMap(object):
         return self._indices[minified_src]
 
     def annotate_stacktrace(self, stacktrace):
-        out = ''
+        # type: (text_type) -> text_type
+        out = '' # type: text_type
         for ln in stacktrace.splitlines():
             out += ln + '\n'
             match = re.search(r'/static/min/(.+)(\.[0-9a-f]+)\.js:(\d+):(\d+)', ln)

zerver/views/users.py

@@ -85,7 +85,7 @@ def update_user_backend(request, user_profile, email,
     return json_success({})
 
 def avatar(request, email):
-    # type: (HttpRequest, text_type) -> HttpResponse
+    # type: (HttpRequest, str) -> HttpResponse
     try:
         user_profile = get_user_profile_by_email(email)
         avatar_source = user_profile.avatar_source