Python >= 3.8 modified TestSuite._handleClassSetUpPost in a way that broke our monkey-patch. This adds an updated monkey-patch for versions >= 3.8. Part of the investigation in #215.

CleanCut · CleanCut · commit 9f393edcaacc · 2020-04-22T13:15:04.000-06:00
diff --git a/green/suite.py b/green/suite.py
@@ -81,7 +81,7 @@ def countTestCases(self):
                 cases += test.countTestCases()
         return cases
 
-    def _handleClassSetUpFIXED(self, test, result):
+    def _handleClassSetUpPre38(self, test, result):
         previousClass = getattr(result, '_previousTestClass', None)
         currentClass = test.__class__
         if currentClass == previousClass:
@@ -117,8 +117,56 @@ def _handleClassSetUpFIXED(self, test, result):
                 self._addClassOrModuleLevelException(result, e, errorName)
             finally:
                 _call_if_exists(result, '_restoreStdout')
+
+    def _handleClassSetUpPost38(self, test, result):
+        previousClass = getattr(result, '_previousTestClass', None)
+        currentClass = test.__class__
+        if currentClass == previousClass:
+            return
+        if result._moduleSetUpFailed:
+            return
+        if getattr(currentClass, "__unittest_skip__", False):
+            return
+
+        try:
+            currentClass._classSetupFailed = False
+        except TypeError:
+            # test may actually be a function
+            # so its class will be a builtin-type
+            pass
+
+        setUpClass = getattr(currentClass, 'setUpClass', None)
+        if setUpClass is not None:
+            _call_if_exists(result, '_setupStdout')
+            try:
+                setUpClass()
+            # THIS is the part Python doesn't get right
+            except unittest.case.SkipTest as e:
+                currentClass.__unittest_skip__ = True
+                currentClass.__unittest_skip_why__ = str(e)
+            # -- END of fix
+            except Exception as e:
+                if isinstance(result, _DebugResult):
+                    raise
+                currentClass._classSetupFailed = True
+                className = util.strclass(currentClass)
+                self._createClassOrModuleLevelException(result, e,
+                                                        'setUpClass',
+                                                        className)
+            finally:
+                _call_if_exists(result, '_restoreStdout')
+                if currentClass._classSetupFailed is True:
+                    currentClass.doClassCleanups()
+                    if len(currentClass.tearDown_exceptions) > 0:
+                        for exc in currentClass.tearDown_exceptions:
+                            self._createClassOrModuleLevelException(
+                                    result, exc[1], 'setUpClass', className,
+                                    info=exc)
+
     if sys.version_info < (3,8): # pragma: no cover
-        _handleClassSetUp = _handleClassSetUpFIXED
+        _handleClassSetUp = _handleClassSetUpPre38
+    else:
+        _handleClassSetUp = _handleClassSetUpPost38
 
 
     def run(self, result):
diff --git a/green/test/test_suite.py b/green/test/test_suite.py
@@ -144,14 +144,13 @@ def test_skip_in_setUpClass(self):
             import unittest
             class Skipper(unittest.TestCase):
                 @classmethod
-                def setUpClass(self):
+                def setUpClass(cls):
                     raise unittest.SkipTest("the skip reason")
                 def test_one(self):
                     pass
                 def test_two(self):
                     pass
-                import unittest
-            """.format(os.getpid())))
+            """))
         fh.close()
         os.chdir(sub_tmpdir)
 
