mypy: Enable redundant-expr error.

Signed-off-by: Anders Kaseorg <anders@zulip.com>

pyproject.toml

@@ -36,6 +36,7 @@ warn_return_any = false
 # Enable optional errors.
 enable_error_code = [
     "redundant-self",
+    "redundant-expr",
     "truthy-bool",
     "truthy-iterable",
     "unused-awaitable",

zulip/integrations/rss/rss-bot

@@ -14,7 +14,7 @@ import sys
 import time
 import urllib.parse
 from html.parser import HTMLParser
-from typing import Any, Dict, List, Tuple
+from typing import Any, Dict, List, Optional, Tuple
 
 import feedparser
 
@@ -225,7 +225,9 @@ for feed_url in feed_urls:
     for entry in data.entries:
         entry_hash = compute_entry_hash(entry)
         # An entry has either been published or updated.
-        entry_time: Tuple[int, int] = entry.get("published_parsed", entry.get("updated_parsed"))
+        entry_time: Optional[Tuple[int, int]] = entry.get(
+            "published_parsed", entry.get("updated_parsed")
+        )
         if (
             entry_time is not None
             and (time.time() - calendar.timegm(entry_time)) > OLDNESS_THRESHOLD * 60 * 60 * 24

zulip_bots/zulip_bots/bots/salesforce/salesforce.py

@@ -152,7 +152,7 @@ class SalesforceHandler:
             for command_keyword in command["commands"]:
                 if content.startswith(command_keyword):
                     args = content.replace(command_keyword, "").strip()
-                    if args is not None and args != "":
+                    if args != "":
                         if "callback" in command.keys():
                             return command["callback"](args, self.sf, command)
                         else: