fix: guard against unknown fields in the snapd JSON response payload

snap_http/types.py

@@ -2,7 +2,7 @@
 
 import json
 from abc import ABC, abstractproperty
-from dataclasses import dataclass
+from dataclasses import dataclass, fields
 from functools import cached_property
 from io import BytesIO
 from pathlib import Path
@@ -38,13 +38,21 @@ class SnapdResponse:
     change: Union[str, None] = None
     warning_timestamp: Union[str, None] = None
     warning_count: Union[int, None] = None
+    suggested_currency: Union[str, None] = None
 
     @classmethod
     def from_http_response(
         cls: Type["SnapdResponse"], response: Dict[str, Any]
     ) -> SnapdResponse:
-        return cls(**{k.replace("-", "_"): v for k, v in response.items()})
-
+        # In case snapd returns to us unknown fields in its response
+        cls_fields = {f.name for f in fields(cls)}
+        filtered_fields = {}
+
+        for k, v in response.items():
+            key = k.replace("-", "_")
+            if key in cls_fields:
+                filtered_fields[key] = v
+        return cls(**filtered_fields)
 
 class AbstractRequestBody(ABC):
     """An abstract base class for the request body of a HTTP request."""

tests/unit/test_types.py

@@ -108,3 +108,22 @@ def test_assertion_data_serialization():
     body = types.AssertionData("assertion-header: value\n\nsignature")
     assert body.content_type == "application/x.ubuntu.assertion"
     assert body.serialized == b"assertion-header: value\n\nsignature"
+
+
+def test_data_serialization_filter():
+    """Test filtering of unknown response data fields."""
+    mock_response = {
+        "type": "async",
+        "status_code": 200,
+        "status": "Accepted",
+        "result": None,
+        "unknown": "bogus",
+    }
+
+    resp = types.SnapdResponse.from_http_response(mock_response)
+
+    assert not hasattr(resp, "unknown")
+    assert resp.type == "async"
+    assert resp.status_code == 200
+    assert resp.status == "Accepted"
+    assert resp.result is None