From 94c863a2040fb04302cc86eb7b600e914e11f224 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Sun, 21 Jul 2024 10:26:04 -0500
Subject: [PATCH] Restore AsyncResolver to be the default resolver (#8522)

(cherry picked from commit 5a9e500633a06648d3ea1627b5056b15b9e7db26)
---
 CHANGES/8522.misc.rst  |  5 +++++
 aiohttp/resolver.py    |  6 +++---
 tests/test_resolver.py | 12 +++++++-----
 3 files changed, 15 insertions(+), 8 deletions(-)
 create mode 100644 CHANGES/8522.misc.rst

diff --git a/CHANGES/8522.misc.rst b/CHANGES/8522.misc.rst
new file mode 100644
index 00000000000..04f7edcc92d
--- /dev/null
+++ b/CHANGES/8522.misc.rst
@@ -0,0 +1,5 @@
+Restore :py:class:`~aiohttp.resolver.AsyncResolver` to be the default resolver. -- by :user:`bdraco`.
+
+:py:class:`~aiohttp.resolver.AsyncResolver` was disabled by default because
+of IPv6 compatibility issues. These issues have been resolved and
+:py:class:`~aiohttp.resolver.AsyncResolver` is again now the default resolver.
diff --git a/aiohttp/resolver.py b/aiohttp/resolver.py
index 3d14d2fcb16..10e36266abe 100644
--- a/aiohttp/resolver.py
+++ b/aiohttp/resolver.py
@@ -7,16 +7,16 @@
 
 __all__ = ("ThreadedResolver", "AsyncResolver", "DefaultResolver")
 
+
 try:
     import aiodns
 
-    # aiodns_default = hasattr(aiodns.DNSResolver, 'getaddrinfo')
+    aiodns_default = hasattr(aiodns.DNSResolver, "getaddrinfo")
 except ImportError:  # pragma: no cover
     aiodns = None  # type: ignore[assignment]
+    aiodns_default = False
 
 
-aiodns_default = False
-
 _NUMERIC_SOCKET_FLAGS = socket.AI_NUMERICHOST | socket.AI_NUMERICSERV
 _SUPPORTS_SCOPE_ID = sys.version_info >= (3, 9, 0)
 
diff --git a/tests/test_resolver.py b/tests/test_resolver.py
index fe1902180dd..f51506a6999 100644
--- a/tests/test_resolver.py
+++ b/tests/test_resolver.py
@@ -328,9 +328,11 @@ async def test_async_resolver_aiodns_not_present(loop, monkeypatch) -> None:
         AsyncResolver(loop=loop)
 
 
-def test_default_resolver() -> None:
-    # if getaddrinfo:
-    #     assert DefaultResolver is AsyncResolver
-    # else:
-    #     assert DefaultResolver is ThreadedResolver
+@pytest.mark.skipif(not getaddrinfo, reason="aiodns >=3.2.0 required")
+def test_aio_dns_is_default() -> None:
+    assert DefaultResolver is AsyncResolver
+
+
+@pytest.mark.skipif(getaddrinfo, reason="aiodns <3.2.0 required")
+def test_threaded_resolver_is_default() -> None:
     assert DefaultResolver is ThreadedResolver