Fix loading netrc when NETRC env var is not set

CHANGES/11713.bugfix.rst

@@ -0,0 +1 @@
+Fixed loading netrc credentials from the default ``~/.netrc`` location when the ``NETRC`` environment variable is not set -- by :user:`bdraco`.

CHANGES/11714.bugfix.rst

@@ -0,0 +1 @@
+11713.bugfix.rst

aiohttp/client.py

@@ -590,14 +590,7 @@ async def _request(
                         auth = self._default_auth
 
                     # Try netrc if auth is still None and trust_env is enabled.
-                    # Only check if NETRC environment variable is set to avoid
-                    # creating an expensive executor job unnecessarily.
-                    if (
-                        auth is None
-                        and self._trust_env
-                        and url.host is not None
-                        and os.environ.get("NETRC")
-                    ):
+                    if auth is None and self._trust_env and url.host is not None:
                         auth = await self._loop.run_in_executor(
                             None, self._get_netrc_auth, url.host
                         )

tests/conftest.py

@@ -1,6 +1,7 @@
 import asyncio
 import base64
 import os
+import platform
 import socket
 import ssl
 import sys
@@ -316,6 +317,24 @@ def netrc_other_host(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> Path:
     return netrc_file
 
 
+@pytest.fixture
+def netrc_home_directory(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> Path:
+    """Create a netrc file in a mocked home directory without setting NETRC env var."""
+    # Create a fake home directory with .netrc or _netrc (Windows)
+    home_dir = tmp_path / "home"
+    home_dir.mkdir()
+    netrc_filename = "_netrc" if platform.system() == "Windows" else ".netrc"
+    netrc_file = home_dir / netrc_filename
+    netrc_file.write_text("default login netrc_user password netrc_pass\n")
+
+    # Mock Path.home() to return our fake home directory
+    monkeypatch.setattr("pathlib.Path.home", lambda: home_dir)
+    # Ensure NETRC env var is not set
+    monkeypatch.delenv("NETRC", raising=False)
+
+    return netrc_file
+
+
 @pytest.fixture
 def start_connection() -> Iterator[mock.Mock]:
     with mock.patch(

tests/test_client_functional.py

@@ -3775,12 +3775,12 @@ async def test_netrc_auth_from_env(  # type: ignore[misc]
 
 
 @pytest.mark.usefixtures("no_netrc")
-async def test_netrc_auth_skipped_without_env_var(  # type: ignore[misc]
+async def test_netrc_auth_skipped_without_netrc_file(  # type: ignore[misc]
     headers_echo_client: Callable[
         ..., Awaitable[TestClient[web.Request, web.Application]]
     ],
 ) -> None:
-    """Test that netrc authentication is skipped when NETRC env var is not set."""
+    """Test that netrc authentication is skipped when no netrc file exists."""
     client = await headers_echo_client(trust_env=True)
     async with client.get("/") as r:
         assert r.status == 200
@@ -3789,6 +3789,20 @@ async def test_netrc_auth_skipped_without_env_var(  # type: ignore[misc]
     assert "Authorization" not in content["headers"]
 
 
+@pytest.mark.usefixtures("netrc_home_directory")
+async def test_netrc_auth_from_home_directory(  # type: ignore[misc]
+    headers_echo_client: Callable[
+        ..., Awaitable[TestClient[web.Request, web.Application]]
+    ],
+) -> None:
+    """Test that netrc authentication works from default ~/.netrc without NETRC env var."""
+    client = await headers_echo_client(trust_env=True)
+    async with client.get("/") as r:
+        assert r.status == 200
+        content = await r.json()
+    assert content["headers"]["Authorization"] == "Basic bmV0cmNfdXNlcjpuZXRyY19wYXNz"
+
+
 @pytest.mark.usefixtures("netrc_default_contents")
 async def test_netrc_auth_overridden_by_explicit_auth(  # type: ignore[misc]
     headers_echo_client: Callable[

tests/test_client_session.py

@@ -1368,8 +1368,8 @@ async def test_netrc_auth_skipped_without_trust_env(auth_server: TestServer) ->
 
 
 @pytest.mark.usefixtures("no_netrc")
-async def test_netrc_auth_skipped_without_netrc_env(auth_server: TestServer) -> None:
-    """Test that netrc authentication is skipped when NETRC env var is not set."""
+async def test_netrc_auth_skipped_without_netrc_file(auth_server: TestServer) -> None:
+    """Test that netrc authentication is skipped when no netrc file exists."""
     async with (
         ClientSession(trust_env=True) as session,
         session.get(auth_server.make_url("/")) as resp,
@@ -1378,6 +1378,17 @@ async def test_netrc_auth_skipped_without_netrc_env(auth_server: TestServer) ->
         assert text == "no_auth"
 
 
+@pytest.mark.usefixtures("netrc_home_directory")
+async def test_netrc_auth_from_home_directory(auth_server: TestServer) -> None:
+    """Test that netrc authentication works from default ~/.netrc location without NETRC env var."""
+    async with (
+        ClientSession(trust_env=True) as session,
+        session.get(auth_server.make_url("/")) as resp,
+    ):
+        text = await resp.text()
+        assert text == "auth:Basic bmV0cmNfdXNlcjpuZXRyY19wYXNz"
+
+
 @pytest.mark.usefixtures("netrc_default_contents")
 async def test_netrc_auth_overridden_by_explicit_auth(auth_server: TestServer) -> None:
     """Test that explicit auth parameter overrides netrc authentication."""