fix: `_json_or_string` no longer fails on malformed unicode buffers (#184)

* fix: add missing decode exception

Signed-off-by: Alexander Tkachev <sasha64sasha@gmail.com>

* fix: add optional to signature

Signed-off-by: Alexander Tkachev <sasha64sasha@gmail.com>

* refactor: better type information

Signed-off-by: Alexander Tkachev <sasha64sasha@gmail.com>

* test: json or string

Signed-off-by: Alexander Tkachev <sasha64sasha@gmail.com>

* docs: update changelog

Signed-off-by: Alexander Tkachev <sasha64sasha@gmail.com>

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Signed-off-by: Alexander Tkachev <sasha64sasha@gmail.com>

* refactor: use anystr

Co-authored-by: Yurii Serhiichuk <xSAVIKx@users.noreply.github.com>
Signed-off-by: Alexander Tkachev <sasha64sasha@gmail.com>

* refactor: use anystr instead of custom type var

Signed-off-by: Alexander Tkachev <sasha64sasha@gmail.com>

* docs: _json_or_string

Signed-off-by: Alexander Tkachev <sasha64sasha@gmail.com>

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Yurii Serhiichuk <xSAVIKx@users.noreply.github.com>

CHANGELOG.md

@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Fixed
+- Malformed unicode buffer encoded in `base_64` json field no-longer fail CloudEvent
+ class construction ([#184])
 
 ### Changed
 - Default branch changed from `master` to `main` ([#180])
@@ -169,3 +172,4 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 [#172]: https://github.com/cloudevents/sdk-python/pull/172
 [#173]: https://github.com/cloudevents/sdk-python/pull/173
 [#180]: https://github.com/cloudevents/sdk-python/pull/180
+[#184]: https://github.com/cloudevents/sdk-python/pull/184

cloudevents/http/util.py

@@ -25,10 +25,22 @@ def default_marshaller(content: any):
         return content
 
 
-def _json_or_string(content: typing.Union[str, bytes]):
+def _json_or_string(
+    content: typing.Optional[typing.AnyStr],
+) -> typing.Optional[
+    typing.Union[
+        typing.Dict[typing.Any, typing.Any],
+        typing.List[typing.Any],
+        typing.AnyStr,
+    ]
+]:
+    """
+    Given an encoded JSON string MUST return decoded JSON object.
+    Otherwise, MUST return the given string as-is.
+    """
     if content is None:
         return None
     try:
         return json.loads(content)
-    except (json.JSONDecodeError, TypeError):
+    except (json.JSONDecodeError, TypeError, UnicodeDecodeError):
         return content

cloudevents/tests/test_http_cloudevent.py

@@ -168,8 +168,19 @@ def test_cloudevent_general_overrides():
     assert len(event) == 0
 
 
-def test_none_json_or_string():
-    assert _json_or_string(None) is None
+@pytest.mark.parametrize(
+    "given, expected",
+    [
+        (None, None),
+        ('{"hello": "world"}', {"hello": "world"}),
+        (b'{"hello": "world"}', {"hello": "world"}),
+        (b"Hello World", b"Hello World"),
+        ("Hello World", "Hello World"),
+        (b"\x00\x00\x11Hello World", b"\x00\x00\x11Hello World"),
+    ],
+)
+def test_json_or_string_match_golden_sample(given, expected):
+    assert _json_or_string(given) == expected
 
 
 def test_get_operation_on_non_existing_attribute_must_not_raise_exception(