Utils: YAML goes brrrt (#2868)

Also tests to validate we dont break the API.

Utils.py

@@ -19,14 +19,12 @@ import warnings
 from argparse import Namespace
 from settings import Settings, get_settings
 from typing import BinaryIO, Coroutine, Optional, Set, Dict, Any, Union
-from yaml import load, load_all, dump, SafeLoader
+from yaml import load, load_all, dump
 
 try:
-    from yaml import CLoader as UnsafeLoader
+    from yaml import CLoader as UnsafeLoader, CSafeLoader as SafeLoader, CDumper as Dumper
-    from yaml import CDumper as Dumper
 except ImportError:
-    from yaml import Loader as UnsafeLoader
+    from yaml import Loader as UnsafeLoader, SafeLoader, Dumper
-    from yaml import Dumper
 
 if typing.TYPE_CHECKING:
     import tkinter

test/utils/test_yaml.py

@@ -0,0 +1,68 @@
+# Tests that yaml wrappers in Utils.py do what they should
+
+import unittest
+from typing import cast, Any, ClassVar, Dict
+
+from Utils import dump, Dumper  # type: ignore[attr-defined]
+from Utils import parse_yaml, parse_yamls, unsafe_parse_yaml
+
+
+class AClass:
+    def __eq__(self, other: Any) -> bool:
+        return isinstance(other, self.__class__)
+
+
+class TestYaml(unittest.TestCase):
+    safe_data: ClassVar[Dict[str, Any]] = {
+        "a": [1, 2, 3],
+        "b": None,
+        "c": True,
+    }
+    unsafe_data: ClassVar[Dict[str, Any]] = {
+        "a": AClass()
+    }
+
+    @property
+    def safe_str(self) -> str:
+        return cast(str, dump(self.safe_data, Dumper=Dumper))
+
+    @property
+    def unsafe_str(self) -> str:
+        return cast(str, dump(self.unsafe_data, Dumper=Dumper))
+
+    def assertIsNonEmptyString(self, string: str) -> None:
+        self.assertTrue(string)
+        self.assertIsInstance(string, str)
+
+    def test_dump(self) -> None:
+        self.assertIsNonEmptyString(self.safe_str)
+        self.assertIsNonEmptyString(self.unsafe_str)
+
+    def test_safe_parse(self) -> None:
+        self.assertEqual(self.safe_data, parse_yaml(self.safe_str))
+        with self.assertRaises(Exception):
+            parse_yaml(self.unsafe_str)
+        with self.assertRaises(Exception):
+            parse_yaml("1\n---\n2\n")
+
+    def test_unsafe_parse(self) -> None:
+        self.assertEqual(self.safe_data, unsafe_parse_yaml(self.safe_str))
+        self.assertEqual(self.unsafe_data, unsafe_parse_yaml(self.unsafe_str))
+        with self.assertRaises(Exception):
+            unsafe_parse_yaml("1\n---\n2\n")
+
+    def test_multi_parse(self) -> None:
+        self.assertEqual(self.safe_data, next(parse_yamls(self.safe_str)))
+        with self.assertRaises(Exception):
+            next(parse_yamls(self.unsafe_str))
+        self.assertEqual(2, len(list(parse_yamls("1\n---\n2\n"))))
+
+    def test_unique_key(self) -> None:
+        s = """
+        a: 1
+        a: 2
+        """
+        with self.assertRaises(Exception):
+            parse_yaml(s)
+        with self.assertRaises(Exception):
+            next(parse_yamls(s))