init: zero-dep dns-over-https resolver

tests/test_patch.py

@@ -0,0 +1,28 @@
+import socket
+
+from pydoh.patch import patch_socket, unpatch_socket
+
+
+def test_patch_and_unpatch_restores_original():
+    original = socket.getaddrinfo
+    patch_socket()
+    assert socket.getaddrinfo is not original
+    unpatch_socket()
+    assert socket.getaddrinfo is original
+
+
+def test_patch_is_idempotent():
+    patch_socket()
+    patched = socket.getaddrinfo
+    patch_socket()
+    assert socket.getaddrinfo is patched
+    unpatch_socket()
+
+
+def test_ip_literal_bypasses_doh():
+    patch_socket()
+    try:
+        result = socket.getaddrinfo("127.0.0.1", 80)
+        assert result
+    finally:
+        unpatch_socket()