gen,test: Remove conditional imports of modules that are now standard

diff --git a/tornado/gen.py b/tornado/gen.py
index 4e5e4cde9224dd527ef57130e2f8d94135088a29..d3b694414e2aa2af99da71c0101536f93140732e 100644 (file)
--- a/tornado/gen.py
+++ b/tornado/gen.py
@@ -66,6 +66,7 @@ import builtins
 import collections
 from collections.abc import Generator
 import concurrent.futures
+import contextvars
 import datetime
 import functools
 from functools import singledispatch
@@ -85,11 +86,6 @@ from tornado.ioloop import IOLoop
 from tornado.log import app_log
 from tornado.util import TimeoutError
 
-try:
-    import contextvars
-except ImportError:
-    contextvars = None  # type: ignore
-
 import typing
 from typing import (
     Union,
@@ -207,10 +203,7 @@ def coroutine(
         # This function is type-annotated with a comment to work around
         # https://bitbucket.org/pypy/pypy/issues/2868/segfault-with-args-type-annotation-in
         future = _create_future()
-        if contextvars is not None:
-            ctx_run: Callable = contextvars.copy_context().run
-        else:
-            ctx_run = _fake_ctx_run
+        ctx_run: Callable = contextvars.copy_context().run
         try:
             result = ctx_run(func, *args, **kwargs)
         except (Return, StopIteration) as e:

diff --git a/tornado/test/auth_test.py b/tornado/test/auth_test.py
index 834f04ea309bdda995c22e7aefb557fee9861c22..f361d1b7a92d7b22ececb07df40683f3bb4b1f73 100644 (file)
--- a/tornado/test/auth_test.py
+++ b/tornado/test/auth_test.py
@@ -3,7 +3,7 @@
 # and ensure that it doesn't blow up (e.g. with unicode/bytes issues in
 # python 3)
 
-import unittest
+from unittest import mock
 
 from tornado.auth import (
     OpenIdMixin,
@@ -21,11 +21,6 @@ from tornado.log import app_log
 from tornado.testing import AsyncHTTPTestCase, ExpectLog
 from tornado.web import RequestHandler, Application, HTTPError
 
-try:
-    from unittest import mock
-except ImportError:
-    mock = None  # type: ignore
-
 
 class OpenIdClientLoginHandler(RequestHandler, OpenIdMixin):
     def initialize(self, test):
@@ -403,7 +398,6 @@ class AuthTest(AsyncHTTPTestCase):
             response.headers["Set-Cookie"],
         )
 
-    @unittest.skipIf(mock is None, "mock package not present")
     def test_oauth10a_redirect_error(self):
         with mock.patch.object(OAuth1ServerRequestTokenHandler, "get") as get:
             get.side_effect = Exception("boom")

diff --git a/tornado/test/gen_test.py b/tornado/test/gen_test.py
index 66043e74a608d7109949523fe28ac5af8704e65c..598b23895b4aff82ff34cf64ccc119560d878170 100644 (file)
--- a/tornado/test/gen_test.py
+++ b/tornado/test/gen_test.py
@@ -1,5 +1,6 @@
 import asyncio
 from concurrent import futures
+import contextvars
 import gc
 import datetime
 import platform
@@ -16,11 +17,6 @@ from tornado.web import Application, RequestHandler, HTTPError
 
 from tornado import gen
 
-try:
-    import contextvars
-except ImportError:
-    contextvars = None  # type: ignore
-
 
 class GenBasicTest(AsyncTestCase):
     @gen.coroutine
@@ -1043,11 +1039,9 @@ class RunnerGCTest(AsyncTestCase):
         self.assertEqual(result, [None, None])
 
 
-if contextvars is not None:
-    ctx_var: contextvars.ContextVar[int] = contextvars.ContextVar("ctx_var")
+ctx_var: contextvars.ContextVar[int] = contextvars.ContextVar("ctx_var")
 
 
-@unittest.skipIf(contextvars is None, "contextvars module not present")
 class ContextVarsTest(AsyncTestCase):
     async def native_root(self, x):
         ctx_var.set(x)