From d7b6ad4b600fb8c89683d6efa6b350d5d47a5700 Mon Sep 17 00:00:00 2001
From: Johannes Gijsbers <jlg@dds.nl>
Date: Sun, 7 Nov 2004 15:46:25 +0000
Subject: [PATCH] Patch #1061904 / bug #878275: give a nicer error message when
 someone accidentally derives from TestSuite instead of TestCase.

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

diff --git a/Lib/unittest.py b/Lib/unittest.py
index 3375067c8d0..70645fbce5d 100644
--- a/Lib/unittest.py
+++ b/Lib/unittest.py
@@ -489,6 +489,8 @@ class TestLoader:
 
     def loadTestsFromTestCase(self, testCaseClass):
         """Return a suite of all tests cases contained in testCaseClass"""
+        if issubclass(testCaseClass, TestSuite):
+            raise TypeError("Test cases should not be derived from TestSuite. Maybe you meant to derive from TestCase?")
         testCaseNames = self.getTestCaseNames(testCaseClass)
         if not testCaseNames and hasattr(testCaseClass, 'runTest'):
             testCaseNames = ['runTest']