test: Remove some CiTestCase tests (#5256)

Includes:
 - test_atomic_helper.py
 - test_builtin_handlers.py
 - test_conftest.py (partial)

tests/unittests/test_atomic_helper.py

@@ -5,67 +5,66 @@
 import stat
 
 from cloudinit import atomic_helper
-from tests.unittests.helpers import CiTestCase
 
 
-class TestAtomicHelper(CiTestCase):
-    def test_basic_usage(self):
+class TestAtomicHelper:
+    def test_basic_usage(self, tmp_path):
         """write_file takes bytes if no omode."""
-        path = self.tmp_path("test_basic_usage")
+        path = tmp_path / "test_basic_usage"
         contents = b"Hey there\n"
         atomic_helper.write_file(path, contents)
         self.check_file(path, contents)
 
-    def test_string(self):
+    def test_string(self, tmp_path):
         """write_file can take a string with mode w."""
-        path = self.tmp_path("test_string")
+        path = tmp_path / "test_string"
         contents = "Hey there\n"
         atomic_helper.write_file(path, contents, omode="w")
         self.check_file(path, contents, omode="r")
 
-    def test_file_permissions(self):
+    def test_file_permissions(self, tmp_path):
         """write_file with mode 400 works correctly."""
-        path = self.tmp_path("test_file_permissions")
+        path = tmp_path / "test_file_permissions"
         contents = b"test_file_perms"
         atomic_helper.write_file(path, contents, mode=0o400)
         self.check_file(path, contents, perms=0o400)
 
-    def test_file_preserve_permissions(self):
+    def test_file_preserve_permissions(self, tmp_path):
         """create a file with mode 700, then write_file with mode 644."""
-        path = self.tmp_path("test_file_preserve_permissions")
+        path = tmp_path / "test_file_preserve_permissions"
         contents = b"test_file_perms"
         with open(path, mode="wb") as f:
             f.write(b"test file preserve permissions")
             os.chmod(f.name, 0o700)
             atomic_helper.write_file(path, contents, preserve_mode=True)
             self.check_file(path, contents, perms=0o700)
 
-    def test_write_json(self):
+    def test_write_json(self, tmp_path):
         """write_json output is readable json."""
-        path = self.tmp_path("test_write_json")
+        path = tmp_path / "test_write_json"
         data = {"key1": "value1", "key2": ["i1", "i2"]}
         atomic_helper.write_json(path, data)
         with open(path, "r") as fp:
             found = json.load(fp)
-        self.assertEqual(data, found)
+        assert data == found
         self.check_perms(path, 0o644)
 
     def check_file(self, path, content, omode=None, perms=0o644):
         if omode is None:
             omode = "rb"
-        self.assertTrue(os.path.exists(path))
-        self.assertTrue(os.path.isfile(path))
+        assert os.path.exists(path)
+        assert os.path.isfile(path)
         with open(path, omode) as fp:
             found = fp.read()
-            self.assertEqual(content, found)
+            assert content == found
         self.check_perms(path, perms)
 
     def check_perms(self, path, perms):
         file_stat = os.stat(path)
-        self.assertEqual(perms, stat.S_IMODE(file_stat.st_mode))
+        assert perms == stat.S_IMODE(file_stat.st_mode)
 
-    def test_write_file_ensure_dirs(self):
-        path = self.tmp_path("ensure_dirs") + "/ensure/dir"
+    def test_write_file_ensure_dirs(self, tmp_path):
+        path = tmp_path / "ensure_dirs" / "ensure/dir"
         contents = b"Hey there\n"
         atomic_helper.write_file(path, contents)
         self.check_file(path, contents)