From d7d4e0b0b65101247275179dd88cf8a74b71f0b0 Mon Sep 17 00:00:00 2001
From: Irit Katriel <iritkatriel@yahoo.com>
Date: Sun, 23 Jan 2022 17:38:45 +0000
Subject: [PATCH 1/3] bpo-41403: Improve error message for invalid mock target

---
 Lib/unittest/mock.py                    | 2 +-
 Lib/unittest/test/testmock/testpatch.py | 9 +++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index 9f99a5aa5bcdcb..517a9fe936255d 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -1589,7 +1589,7 @@ def stop(self):
 def _get_target(target):
     try:
         target, attribute = target.rsplit('.', 1)
-    except (TypeError, ValueError):
+    except (TypeError, ValueError, AttributeError):
         raise TypeError("Need a valid target to patch. You supplied: %r" %
                         (target,))
     return partial(pkgutil.resolve_name, target), attribute
diff --git a/Lib/unittest/test/testmock/testpatch.py b/Lib/unittest/test/testmock/testpatch.py
index 233a5afffaed4a..8ab63a1317d3df 100644
--- a/Lib/unittest/test/testmock/testpatch.py
+++ b/Lib/unittest/test/testmock/testpatch.py
@@ -1933,8 +1933,13 @@ def test(mock):
 
 
     def test_invalid_target(self):
-        with self.assertRaises(TypeError):
-            patch('')
+        class Foo:
+            pass
+
+        for target in ['', 12, Foo()]:
+            with self.subTest(target=target):
+                with self.assertRaises(TypeError):
+                    patch(target)
 
 
     def test_cant_set_kwargs_when_passing_a_mock(self):

From 6460ea15430875fb518aca966c2700da13fd4d4a Mon Sep 17 00:00:00 2001
From: Irit Katriel <iritkatriel@yahoo.com>
Date: Sun, 23 Jan 2022 18:05:11 +0000
Subject: [PATCH 2/3] add news

---
 .../next/Library/2022-01-23-18-04-45.bpo-41403.SgoHqV.rst      | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2022-01-23-18-04-45.bpo-41403.SgoHqV.rst

diff --git a/Misc/NEWS.d/next/Library/2022-01-23-18-04-45.bpo-41403.SgoHqV.rst b/Misc/NEWS.d/next/Library/2022-01-23-18-04-45.bpo-41403.SgoHqV.rst
new file mode 100644
index 00000000000000..ede159b25641f3
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-01-23-18-04-45.bpo-41403.SgoHqV.rst
@@ -0,0 +1,3 @@
+Make :meth:`mock.patch` raise a :exc:`TypeError` with a relevant error
+message on invalid arg. Previously it allowed a cryptic
+:exc:`AttributeError` to escape.

From 461e59e4f4ac839c2bbdecf478cca1fec93068a9 Mon Sep 17 00:00:00 2001
From: Irit Katriel <iritkatriel@yahoo.com>
Date: Sun, 23 Jan 2022 18:12:40 +0000
Subject: [PATCH 3/3] use format string

---
 Lib/unittest/mock.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py
index 517a9fe936255d..9137501930000c 100644
--- a/Lib/unittest/mock.py
+++ b/Lib/unittest/mock.py
@@ -1590,8 +1590,8 @@ def _get_target(target):
     try:
         target, attribute = target.rsplit('.', 1)
     except (TypeError, ValueError, AttributeError):
-        raise TypeError("Need a valid target to patch. You supplied: %r" %
-                        (target,))
+        raise TypeError(
+            f"Need a valid target to patch. You supplied: {target!r}")
     return partial(pkgutil.resolve_name, target), attribute