Add ignore_unknown_fields to from_json (#111)

Author: AdrienVannson

betterproto2/src/betterproto2/__init__.py

@@ -1212,7 +1212,7 @@ def to_json(
         )
 
     @classmethod
-    def from_json(cls, value: str | bytes) -> Self:
+    def from_json(cls, value: str | bytes, *, ignore_unknown_fields: bool = False) -> Self:
         """A helper function to return the message instance from its JSON
         representation. This returns the instance itself and is therefore assignable
         and chainable.
@@ -1231,7 +1231,7 @@ def from_json(cls, value: str | bytes) -> Self:
         :class:`Message`
             The initialized message.
         """
-        return cls.from_dict(json.loads(value))
+        return cls.from_dict(json.loads(value), ignore_unknown_fields=ignore_unknown_fields)
 
     def is_set(self, name: str) -> bool:
         """

betterproto2/tests/test_features.py

@@ -65,6 +65,15 @@ def test_from_dict_unknown_fields():
     assert Older.from_dict({"x": True, "y": 1}, ignore_unknown_fields=True) == Older(x=True)
 
 
+def test_from_json_unknown_fields():
+    from tests.output_betterproto.features import Older
+
+    with pytest.raises(KeyError):
+        Older.from_json('{"x": true, "y": 1}')
+
+    assert Older.from_json('{"x": true, "y": 1}', ignore_unknown_fields=True) == Older(x=True)
+
+
 def test_oneof_support():
     from tests.output_betterproto.features import IntMsg, OneofMsg