partial: Replace returns plugin with an annotation.

The returns plugin hasn’t been updated for mypy ≥ 1.6.  This
annotation is more limited in that it only supports a fixed number of
positional arguments and no keyword arguments, but is good enough for
our purposes.

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

pyproject.toml

@@ -48,7 +48,6 @@ local_partial_types = true
 plugins = [
     "mypy_django_plugin.main",
     "pydantic.mypy",
-    "returns.contrib.mypy.returns_plugin",
 ]
 
 [[tool.mypy.overrides]]

tools/run-dev

@@ -21,9 +21,9 @@ sanity_check.check_venv(__file__)
 import aiohttp
 from aiohttp import hdrs, web
 from aiohttp.http_exceptions import BadStatusLine
-from returns.curry import partial
 
 from tools.lib.test_script import add_provision_check_override_param, assert_provisioning_status_ok
+from zerver.lib.partial import partial
 
 if "posix" in os.name and os.geteuid() == 0:
     raise RuntimeError("run-dev should not be run as root.")

tools/semgrep-py.yml

@@ -318,7 +318,7 @@ rules:
 
   - id: functools-partial
     pattern: functools.partial
-    message: "Replace functools.partial with returns.curry.partial for type safety"
+    message: "Replace functools.partial with zerver.lib.partial.partial for type safety"
     languages: [python]
     severity: ERROR
 

zerver/data_import/import_util.py

@@ -24,11 +24,11 @@ import orjson
 import requests
 from django.forms.models import model_to_dict
 from django.utils.timezone import now as timezone_now
-from returns.curry import partial
 from typing_extensions import TypeAlias
 
 from zerver.data_import.sequencer import NEXT_ID
 from zerver.lib.avatar_hash import user_avatar_path_from_ids
+from zerver.lib.partial import partial
 from zerver.lib.stream_color import STREAM_ASSIGNMENT_COLORS as STREAM_COLORS
 from zerver.models import (
     Attachment,

zerver/lib/message.py

@@ -23,7 +23,6 @@ from django.utils.timezone import now as timezone_now
 from django.utils.translation import gettext as _
 from django_stubs_ext import ValuesQuerySet
 from psycopg2.sql import SQL
-from returns.curry import partial
 
 from analytics.lib.counts import COUNT_STATS
 from analytics.models import RealmCount
@@ -33,6 +32,7 @@ from zerver.lib.exceptions import JsonableError, MissingAuthenticationError
 from zerver.lib.markdown import MessageRenderingResult
 from zerver.lib.mention import MentionData
 from zerver.lib.message_cache import MessageDict, extract_message_dict, stringify_message_dict
+from zerver.lib.partial import partial
 from zerver.lib.request import RequestVariableConversionError
 from zerver.lib.stream_subscription import (
     get_stream_subscriptions_for_user,

zerver/lib/partial.py

@@ -0,0 +1,36 @@
+# Workaround for missing functools.partial support in mypy
+# (https://github.com/python/mypy/issues/1484).
+
+from typing import TYPE_CHECKING, Callable, TypeVar, overload
+
+if TYPE_CHECKING:
+    from typing_extensions import Concatenate, ParamSpec
+
+    P = ParamSpec("P")
+    T1 = TypeVar("T1")
+    T2 = TypeVar("T2")
+    T3 = TypeVar("T3")
+    T4 = TypeVar("T4")
+    R = TypeVar("R")
+
+    @overload
+    def partial(func: Callable[P, R], /) -> Callable[P, R]: ...
+    @overload
+    def partial(func: Callable[Concatenate[T1, P], R], arg1: T1, /) -> Callable[P, R]: ...
+    @overload
+    def partial(
+        func: Callable[Concatenate[T1, T2, P], R], arg1: T1, arg2: T2, /
+    ) -> Callable[P, R]: ...
+    @overload
+    def partial(
+        func: Callable[Concatenate[T1, T2, T3, P], R], arg1: T1, arg2: T2, arg3: T3, /
+    ) -> Callable[P, R]: ...
+    @overload
+    def partial(
+        func: Callable[Concatenate[T1, T2, T3, T4, P], R], arg1: T1, arg2: T2, arg3: T3, arg4: T4, /
+    ) -> Callable[P, R]: ...
+
+    def partial(func: Callable[..., R], /, *args: object) -> Callable[..., R]: ...
+
+else:
+    from functools import partial as partial

zerver/lib/test_runner.py

@@ -13,7 +13,6 @@ from django.db import ProgrammingError, connections
 from django.test import runner as django_runner
 from django.test.runner import DiscoverRunner
 from django.test.signals import template_rendered
-from returns.curry import partial
 from typing_extensions import TypeAlias, override
 
 from scripts.lib.zulip_tools import (
@@ -22,6 +21,7 @@ from scripts.lib.zulip_tools import (
     get_or_create_dev_uuid_var_path,
 )
 from zerver.lib import test_helpers
+from zerver.lib.partial import partial
 from zerver.lib.sqlalchemy_utils import get_sqlalchemy_connection
 from zerver.lib.test_fixtures import BACKEND_DATABASE_TEMPLATE
 from zerver.lib.test_helpers import append_instrumentation_data, write_instrumentation_reports

zerver/management/commands/check_redis.py

@@ -4,9 +4,9 @@ from typing import Any, Callable, Optional
 
 from django.conf import settings
 from django.core.management.base import BaseCommand, CommandError, CommandParser
-from returns.curry import partial
 from typing_extensions import override
 
+from zerver.lib.partial import partial
 from zerver.lib.rate_limiter import RateLimitedUser, client
 from zerver.models.users import get_user_profile_by_id
 

zerver/tornado/django_api.py

@@ -9,10 +9,10 @@ from django.conf import settings
 from django.db import transaction
 from requests.adapters import ConnectionError, HTTPAdapter
 from requests.models import PreparedRequest, Response
-from returns.curry import partial
 from typing_extensions import override
 from urllib3.util import Retry
 
+from zerver.lib.partial import partial
 from zerver.lib.queue import queue_json_publish
 from zerver.models import Client, Realm, UserProfile
 from zerver.tornado.sharding import (

zerver/views/video_calls.py

@@ -20,12 +20,12 @@ from django.views.decorators.csrf import csrf_exempt
 from django.views.decorators.http import require_POST
 from oauthlib.oauth2 import OAuth2Error
 from requests_oauthlib import OAuth2Session
-from returns.curry import partial
 
 from zerver.actions.video_calls import do_set_zoom_token
 from zerver.decorator import zulip_login_required
 from zerver.lib.exceptions import ErrorCode, JsonableError
 from zerver.lib.outgoing_http import OutgoingSession
+from zerver.lib.partial import partial
 from zerver.lib.pysa import mark_sanitized
 from zerver.lib.request import REQ, has_request_variables
 from zerver.lib.response import json_success

zerver/webhooks/bitbucket2/view.py

@@ -4,10 +4,10 @@ import string
 from typing import Dict, List, Optional, Protocol
 
 from django.http import HttpRequest, HttpResponse
-from returns.curry import partial
 
 from zerver.decorator import log_unsupported_webhook_event, webhook_view
 from zerver.lib.exceptions import UnsupportedWebhookEventTypeError
+from zerver.lib.partial import partial
 from zerver.lib.response import json_success
 from zerver.lib.typed_endpoint import JsonBodyPayload, typed_endpoint
 from zerver.lib.validator import WildValue, check_bool, check_int, check_string

zerver/webhooks/bitbucket3/view.py

@@ -2,10 +2,10 @@ import string
 from typing import Dict, List, Optional, Protocol
 
 from django.http import HttpRequest, HttpResponse
-from returns.curry import partial
 
 from zerver.decorator import webhook_view
 from zerver.lib.exceptions import UnsupportedWebhookEventTypeError
+from zerver.lib.partial import partial
 from zerver.lib.response import json_success
 from zerver.lib.typed_endpoint import JsonBodyPayload, typed_endpoint
 from zerver.lib.validator import WildValue, check_int, check_none_or, check_string

zerver/webhooks/clubhouse/view.py

@@ -1,10 +1,10 @@
 from typing import Callable, Dict, Iterable, Iterator, List, Optional
 
 from django.http import HttpRequest, HttpResponse
-from returns.curry import partial
 
 from zerver.decorator import webhook_view
 from zerver.lib.exceptions import UnsupportedWebhookEventTypeError
+from zerver.lib.partial import partial
 from zerver.lib.response import json_success
 from zerver.lib.typed_endpoint import JsonBodyPayload, typed_endpoint
 from zerver.lib.validator import (

zerver/webhooks/github/view.py

@@ -3,10 +3,10 @@ from datetime import datetime, timezone
 from typing import Callable, Dict, Optional
 
 from django.http import HttpRequest, HttpResponse
-from returns.curry import partial
 
 from zerver.decorator import log_unsupported_webhook_event, webhook_view
 from zerver.lib.exceptions import UnsupportedWebhookEventTypeError
+from zerver.lib.partial import partial
 from zerver.lib.response import json_success
 from zerver.lib.typed_endpoint import JsonBodyPayload, typed_endpoint
 from zerver.lib.validator import WildValue, check_bool, check_int, check_none_or, check_string

zerver/webhooks/gitlab/view.py

@@ -3,10 +3,10 @@ from typing import Dict, List, Optional, Protocol, Union
 
 from django.http import HttpRequest, HttpResponse
 from pydantic import Json
-from returns.curry import partial
 
 from zerver.decorator import webhook_view
 from zerver.lib.exceptions import UnsupportedWebhookEventTypeError
+from zerver.lib.partial import partial
 from zerver.lib.response import json_success
 from zerver.lib.typed_endpoint import JsonBodyPayload, typed_endpoint
 from zerver.lib.validator import WildValue, check_int, check_none_or, check_string

zerver/webhooks/groove/view.py

@@ -2,10 +2,10 @@
 from typing import Callable, Dict, Optional
 
 from django.http import HttpRequest, HttpResponse
-from returns.curry import partial
 
 from zerver.decorator import webhook_view
 from zerver.lib.exceptions import UnsupportedWebhookEventTypeError
+from zerver.lib.partial import partial
 from zerver.lib.response import json_success
 from zerver.lib.typed_endpoint import JsonBodyPayload, typed_endpoint
 from zerver.lib.validator import WildValue, check_int, check_none_or, check_string, check_url

zerver/webhooks/intercom/view.py

@@ -2,11 +2,11 @@ from html.parser import HTMLParser
 from typing import Callable, Dict, List, Tuple
 
 from django.http import HttpRequest, HttpResponse
-from returns.curry import partial
 from typing_extensions import override
 
 from zerver.decorator import return_success_on_head_request, webhook_view
 from zerver.lib.exceptions import UnsupportedWebhookEventTypeError
+from zerver.lib.partial import partial
 from zerver.lib.response import json_success
 from zerver.lib.typed_endpoint import JsonBodyPayload, typed_endpoint
 from zerver.lib.validator import WildValue, check_int, check_none_or, check_string

zerver/worker/base.py

@@ -12,11 +12,11 @@ import orjson
 import sentry_sdk
 from django.conf import settings
 from django.db import connection
-from returns.curry import partial
 from typing_extensions import override
 
 from zerver.lib.context_managers import lockfile
 from zerver.lib.db_connections import reset_queries
+from zerver.lib.partial import partial
 from zerver.lib.per_request_cache import flush_per_request_caches
 from zerver.lib.pysa import mark_sanitized
 from zerver.lib.queue import SimpleQueueClient