From f4a0c0c0dc2973768e7c43d997ef4a8e5ced7e89 Mon Sep 17 00:00:00 2001
From: Chris Withers <chris@simplistix.co.uk>
Date: Thu, 29 Feb 2024 09:28:00 +0000
Subject: [PATCH] Fix bug where methods on subclasses failed when using
 Replace.on_class

---
 testfixtures/replace.py            |  2 +-
 testfixtures/tests/test_replace.py | 30 ++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/testfixtures/replace.py b/testfixtures/replace.py
index a5c51ba..7077045 100644
--- a/testfixtures/replace.py
+++ b/testfixtures/replace.py
@@ -148,7 +148,7 @@ def _find_container(self, attribute, name: str, break_on_static: bool):
         for referrer in get_referrers(attribute):
             if break_on_static and isinstance(referrer, staticmethod):
                 return None, referrer
-            elif isinstance(referrer, dict) and '__dict__' in referrer:
+            elif isinstance(referrer, dict):
                 if referrer.get(name) is attribute:
                     for container in get_referrers(referrer):
                         if isinstance(container, type):
diff --git a/testfixtures/tests/test_replace.py b/testfixtures/tests/test_replace.py
index a0b7d6b..6db9b25 100644
--- a/testfixtures/tests/test_replace.py
+++ b/testfixtures/tests/test_replace.py
@@ -764,6 +764,36 @@ def method(self, x):
         compare(sample.method(1), expected=2)
         assert SampleClass.__dict__['method'] is original
 
+    def test_method_on_subclass(self):
+
+        class SampleClass:
+
+            def method_a(self, x):
+                return x*2
+
+        class SampleSubClass(SampleClass):
+            """
+            Some doc!
+            """
+
+            def method_b(self, x):
+                return x*3
+
+        original_a = SampleClass.__dict__['method_a']
+        original_b = SampleSubClass.__dict__['method_b']
+        sample = SampleSubClass()
+
+        with Replacer() as replace:
+            replace.on_class(SampleSubClass.method_a, lambda self, x: x*4)
+            replace.on_class(SampleSubClass.method_b, lambda self, x: x*5)
+            compare(sample.method_a(1), expected=4)
+            compare(sample.method_b(1), expected=5)
+
+        compare(sample.method_a(1), expected=2)
+        compare(sample.method_b(1), expected=3)
+        assert SampleClass.__dict__['method_a'] is original_a
+        assert SampleSubClass.__dict__['method_b'] is original_b
+
     def test_attributes_on_class(self):
 
         class SampleClass: