From fbefae59c570f633a57ceb178eb8bd647f7bfdf4 Mon Sep 17 00:00:00 2001
From: Bert Blommers <bblommers@users.noreply.github.com>
Date: Sat, 5 Feb 2022 10:47:38 -0100
Subject: [PATCH] Non-unittest classes use a lowercase setup-method (#4833)

---
 moto/core/models.py                     | 10 +++--
 tests/test_core/test_decorator_calls.py | 50 ++++++++++++++++++++++++-
 2 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/moto/core/models.py b/moto/core/models.py
index 370d6e3c0..3db13879d 100644
--- a/moto/core/models.py
+++ b/moto/core/models.py
@@ -137,11 +137,15 @@ class BaseMockAWS:
             c for c in klass.__mro__ if c not in [unittest.TestCase, object]
         ]
         # Get a list of all userdefined methods
-        supermethods = itertools.chain(
-            *[get_direct_methods_of(c) for c in superclasses]
+        supermethods = list(
+            itertools.chain(*[get_direct_methods_of(c) for c in superclasses])
         )
         # Check whether the user has overridden the setUp-method
-        has_setup_method = "setUp" in supermethods
+        has_setup_method = (
+            ("setUp" in supermethods and unittest.TestCase in klass.__mro__)
+            or "setup" in supermethods
+            or "setup_method" in supermethods
+        )
 
         for attr in itertools.chain(direct_methods, defined_classes):
             if attr.startswith("_"):
diff --git a/tests/test_core/test_decorator_calls.py b/tests/test_core/test_decorator_calls.py
index 8b26f53d7..2f805dcc7 100644
--- a/tests/test_core/test_decorator_calls.py
+++ b/tests/test_core/test_decorator_calls.py
@@ -109,8 +109,9 @@ class TesterWithStaticmethod(object):
 
 
 @mock_s3
-class TestWithSetup(unittest.TestCase):
+class TestWithSetup_UppercaseU(unittest.TestCase):
     def setUp(self):
+        # This method will be executed automatically, provided we extend the TestCase-class
         s3 = boto3.client("s3", region_name="us-east-1")
         s3.create_bucket(Bucket="mybucket")
 
@@ -124,6 +125,53 @@ class TestWithSetup(unittest.TestCase):
             s3.head_bucket(Bucket="unknown_bucket")
 
 
+@mock_s3
+class TestWithSetup_LowercaseU:
+    def setup(self, *args):
+        # This method will be executed automatically using pytest
+        s3 = boto3.client("s3", region_name="us-east-1")
+        s3.create_bucket(Bucket="mybucket")
+
+    def test_should_find_bucket(self):
+        s3 = boto3.client("s3", region_name="us-east-1")
+        assert s3.head_bucket(Bucket="mybucket") is not None
+
+    def test_should_not_find_unknown_bucket(self):
+        s3 = boto3.client("s3", region_name="us-east-1")
+        with pytest.raises(ClientError):
+            s3.head_bucket(Bucket="unknown_bucket")
+
+
+@mock_s3
+class TestWithSetupMethod:
+    def setup_method(self, *args):
+        # This method will be executed automatically using pytest
+        s3 = boto3.client("s3", region_name="us-east-1")
+        s3.create_bucket(Bucket="mybucket")
+
+    def test_should_find_bucket(self):
+        s3 = boto3.client("s3", region_name="us-east-1")
+        assert s3.head_bucket(Bucket="mybucket") is not None
+
+    def test_should_not_find_unknown_bucket(self):
+        s3 = boto3.client("s3", region_name="us-east-1")
+        with pytest.raises(ClientError):
+            s3.head_bucket(Bucket="unknown_bucket")
+
+
+@mock_s3
+class TestWithInvalidSetupMethod:
+    def setupmethod(self):
+        s3 = boto3.client("s3", region_name="us-east-1")
+        s3.create_bucket(Bucket="mybucket")
+
+    def test_should_not_find_bucket(self):
+        # Name of setupmethod is not recognized, so it will not be executed
+        s3 = boto3.client("s3", region_name="us-east-1")
+        with pytest.raises(ClientError):
+            s3.head_bucket(Bucket="mybucket")
+
+
 @mock_s3
 class TestWithPublicMethod(unittest.TestCase):
     def ensure_bucket_exists(self):