feat: emit warning before raising on blocked calls

src/pytest_socket/__init__.py

@@ -3,6 +3,7 @@
 import ipaddress
 import itertools
 import socket
+import warnings
 from collections import defaultdict
 from collections.abc import Iterator
 from dataclasses import dataclass, field
@@ -16,7 +17,9 @@
 
 class SocketBlockedError(RuntimeError):
     def __init__(self, *_args: Any, **_kwargs: Any) -> None:
-        super().__init__("A test tried to use socket.socket.")
+        msg = "A test tried to use socket.socket."
+        warnings.warn(msg, stacklevel=2)
+        super().__init__(msg)
 
 
 class SocketConnectBlockedError(RuntimeError):
@@ -28,10 +31,12 @@ def __init__(
         **_kwargs: Any,
     ) -> None:
         allowed_str = ",".join(allowed)
-        super().__init__(
+        msg = (
             "A test tried to use socket.socket.connect() "
             f'with host "{host}" (allowed: "{allowed_str}").'
         )
+        warnings.warn(msg, stacklevel=2)
+        super().__init__(msg)
 
 
 def pytest_addoption(parser: pytest.Parser) -> None:

tests/test_socket.py

@@ -247,6 +247,42 @@ class MySocket(socket.socket):
     assert_socket_blocked(result)
 
 
+def test_blocked_socket_emits_warning(pytester):
+    """Ensure SocketBlockedError emits a warning before raising.
+
+    This makes blocked calls visible in test output even when the
+    exception is caught by a bare ``except Exception`` block.
+    """
+    pytester.makepyfile("""
+        import socket
+
+        def test_swallowed_socket(socket_disabled):
+            try:
+                socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            except Exception:
+                pass  # swallow the error, simulating legacy code
+        """)
+    result = pytester.runpytest("-W", "always::UserWarning", "--disable-socket")
+    result.assert_outcomes(passed=1)
+    result.stdout.fnmatch_lines("*A test tried to use socket.socket.*")
+
+
+def test_blocked_connect_emits_warning(pytester, httpserver):
+    """Ensure SocketConnectBlockedError emits a warning before raising."""
+    pytester.makepyfile(f"""
+        import socket
+
+        def test_swallowed_connect():
+            try:
+                socket.socket().connect(('{httpserver.host}', {httpserver.port}))
+            except Exception:
+                pass  # swallow the error
+        """)
+    result = pytester.runpytest("-W", "always::UserWarning", "--allow-hosts=1.2.3.4")
+    result.assert_outcomes(passed=1)
+    result.stdout.fnmatch_lines("*A test tried to use socket.socket.connect()*")
+
+
 @unix_sockets_only
 def test_unix_domain_sockets_blocked_with_disable_socket(pytester):
     pytester.makepyfile("""