From 916aecd29d5e3c5e02b620fbd38eac6d61ce6a5d Mon Sep 17 00:00:00 2001
From: Jayden Kneller <jayden@arrai.com>
Date: Thu, 18 Oct 2018 17:04:28 -0600
Subject: [PATCH] Fixed #29866 -- Made DiscoverRunner do tests tear down if
 running checks or tests raises an exception.

---
 django/test/runner.py      | 20 ++++++++++---
 tests/test_runner/tests.py | 57 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 73 insertions(+), 4 deletions(-)

diff --git a/django/test/runner.py b/django/test/runner.py
index 38eb5c3be0..ed969cc42f 100644
--- a/django/test/runner.py
+++ b/django/test/runner.py
@@ -602,10 +602,22 @@ class DiscoverRunner:
         self.setup_test_environment()
         suite = self.build_suite(test_labels, extra_tests)
         old_config = self.setup_databases()
-        self.run_checks()
-        result = self.run_suite(suite)
-        self.teardown_databases(old_config)
-        self.teardown_test_environment()
+        run_failed = False
+        try:
+            self.run_checks()
+            result = self.run_suite(suite)
+        except Exception:
+            run_failed = True
+            raise
+        finally:
+            try:
+                self.teardown_databases(old_config)
+                self.teardown_test_environment()
+            except Exception:
+                # Silence teardown exceptions if an exception was raised during
+                # runs to avoid shadowing it.
+                if not run_failed:
+                    raise
         return self.suite_result(suite, result)
 
 
diff --git a/tests/test_runner/tests.py b/tests/test_runner/tests.py
index 9717d329c1..b496d79369 100644
--- a/tests/test_runner/tests.py
+++ b/tests/test_runner/tests.py
@@ -10,6 +10,7 @@ from django import db
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 from django.core.management import call_command
+from django.core.management.base import SystemCheckError
 from django.test import (
     TestCase, TransactionTestCase, skipUnlessDBFeature, testcases,
 )
@@ -407,3 +408,59 @@ class EmptyDefaultDatabaseTest(unittest.TestCase):
         connection = testcases.connections[db.utils.DEFAULT_DB_ALIAS]
         self.assertEqual(connection.settings_dict['ENGINE'], 'django.db.backends.dummy')
         connections_support_transactions()
+
+
+class RunTestsExceptionHandlingTests(unittest.TestCase):
+    def test_run_checks_raises(self):
+        """
+        Teardown functions are run when run_checks() raises SystemCheckError.
+        """
+        with mock.patch('django.test.runner.DiscoverRunner.setup_test_environment'), \
+                mock.patch('django.test.runner.DiscoverRunner.setup_databases'), \
+                mock.patch('django.test.runner.DiscoverRunner.build_suite'), \
+                mock.patch('django.test.runner.DiscoverRunner.run_checks', side_effect=SystemCheckError), \
+                mock.patch('django.test.runner.DiscoverRunner.teardown_databases') as teardown_databases, \
+                mock.patch('django.test.runner.DiscoverRunner.teardown_test_environment') as teardown_test_environment:
+            runner = DiscoverRunner(verbosity=0, interactive=False)
+            with self.assertRaises(SystemCheckError):
+                runner.run_tests(['test_runner_apps.sample.tests_sample.TestDjangoTestCase'])
+            self.assertTrue(teardown_databases.called)
+            self.assertTrue(teardown_test_environment.called)
+
+    def test_run_checks_raises_and_teardown_raises(self):
+        """
+        SystemCheckError is surfaced when run_checks() raises SystemCheckError
+        and teardown databases() raises ValueError.
+        """
+        with mock.patch('django.test.runner.DiscoverRunner.setup_test_environment'), \
+                mock.patch('django.test.runner.DiscoverRunner.setup_databases'), \
+                mock.patch('django.test.runner.DiscoverRunner.build_suite'), \
+                mock.patch('django.test.runner.DiscoverRunner.run_checks', side_effect=SystemCheckError), \
+                mock.patch('django.test.runner.DiscoverRunner.teardown_databases', side_effect=ValueError) \
+                as teardown_databases, \
+                mock.patch('django.test.runner.DiscoverRunner.teardown_test_environment') as teardown_test_environment:
+            runner = DiscoverRunner(verbosity=0, interactive=False)
+            with self.assertRaises(SystemCheckError):
+                runner.run_tests(['test_runner_apps.sample.tests_sample.TestDjangoTestCase'])
+            self.assertTrue(teardown_databases.called)
+            self.assertFalse(teardown_test_environment.called)
+
+    def test_run_checks_passes_and_teardown_raises(self):
+        """
+        Exceptions on teardown are surfaced if no exceptions happen during
+        run_checks().
+        """
+        with mock.patch('django.test.runner.DiscoverRunner.setup_test_environment'), \
+                mock.patch('django.test.runner.DiscoverRunner.setup_databases'), \
+                mock.patch('django.test.runner.DiscoverRunner.build_suite'), \
+                mock.patch('django.test.runner.DiscoverRunner.run_checks'), \
+                mock.patch('django.test.runner.DiscoverRunner.teardown_databases', side_effect=ValueError) \
+                as teardown_databases, \
+                mock.patch('django.test.runner.DiscoverRunner.teardown_test_environment') as teardown_test_environment:
+            runner = DiscoverRunner(verbosity=0, interactive=False)
+            with self.assertRaises(ValueError):
+                # Suppress the output when running TestDjangoTestCase.
+                with mock.patch('sys.stderr'):
+                    runner.run_tests(['test_runner_apps.sample.tests_sample.TestDjangoTestCase'])
+            self.assertTrue(teardown_databases.called)
+            self.assertFalse(teardown_test_environment.called)