From b32af0bffb52c0b80f2c781656fb67ae1de87947 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20Gr=C3=B6nholm?= <alex.gronholm@nextday.fi>
Date: Sun, 3 Nov 2024 14:00:16 +0200
Subject: [PATCH] Added tests against an empty protocol

Closes #491.
---
 tests/test_checkers.py | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tests/test_checkers.py b/tests/test_checkers.py
index 23e01aa..1ba0407 100644
--- a/tests/test_checkers.py
+++ b/tests/test_checkers.py
@@ -1199,6 +1199,20 @@ def my_class_method(x: int, y: str) -> None:
         else:
             check_type(Foo, type[MyProtocol])
 
+    @pytest.mark.parametrize(
+        "instantiate",
+        [pytest.param(True, id="instance"), pytest.param(False, id="class")],
+    )
+    @pytest.mark.parametrize("subject_class", [object, str, Parent])
+    def test_empty_protocol(self, instantiate: bool, subject_class: type[Any]):
+        class EmptyProtocol(Protocol):
+            pass
+
+        if instantiate:
+            check_type(subject_class(), EmptyProtocol)
+        else:
+            check_type(subject_class, type[EmptyProtocol])
+
     @pytest.mark.parametrize("has_member", [True, False])
     def test_member_checks(self, has_member: bool) -> None:
         class MyProtocol(Protocol):