Optionally raise instead of swallowing JSON decode errors

massive/exceptions.py

@@ -12,3 +12,14 @@ class BadResponse(Exception):
     """
 
     pass
+
+
+class ResponseDecodeError(Exception):
+    """
+    Response body could not be decoded as JSON, e.g. a truncated payload.
+
+    Only raised when the client is constructed with raise_on_decode_error=True; the default
+    remains logging the error and returning an empty result.
+    """
+
+    pass

massive/rest/__init__.py

@@ -60,6 +60,7 @@ def __init__(
         verbose: bool = False,
         trace: bool = False,
         custom_json: Optional[Any] = None,
+        raise_on_decode_error: bool = False,
     ):
         super().__init__(
             api_key=api_key,
@@ -72,6 +73,7 @@ def __init__(
             verbose=verbose,
             trace=trace,
             custom_json=custom_json,
+            raise_on_decode_error=raise_on_decode_error,
         )
         self.vx = VXClient(
             api_key=api_key,
@@ -84,4 +86,5 @@ def __init__(
             verbose=verbose,
             trace=trace,
             custom_json=custom_json,
+            raise_on_decode_error=raise_on_decode_error,
         )

massive/rest/base.py

@@ -11,7 +11,7 @@
 from ..logging import get_logger
 import logging
 from urllib.parse import urlencode, urlparse
-from ..exceptions import AuthError, BadResponse
+from ..exceptions import AuthError, BadResponse, ResponseDecodeError
 
 logger = get_logger("RESTClient")
 version_number = "unknown"
@@ -34,6 +34,7 @@ def __init__(
         verbose: bool,
         trace: bool,
         custom_json: Optional[Any] = None,
+        raise_on_decode_error: bool = False,
     ):
         if api_key is None:
             raise AuthError(
@@ -43,6 +44,7 @@ def __init__(
         self.API_KEY = api_key
         self.BASE = base
         self.pagination = pagination
+        self.raise_on_decode_error = raise_on_decode_error
 
         self.headers = {
             "Authorization": "Bearer " + self.API_KEY,
@@ -140,6 +142,10 @@ def _get(
         try:
             obj = self._decode(resp)
         except ValueError as e:
+            if self.raise_on_decode_error:
+                raise ResponseDecodeError(
+                    f"Could not decode response body from {full_url}: {e}"
+                ) from e
             logger.error("Error decoding json response: %s", e)
             return []
 
@@ -226,6 +232,10 @@ def _paginate_iter(
             try:
                 decoded = self._decode(resp)
             except ValueError as e:
+                if self.raise_on_decode_error:
+                    raise ResponseDecodeError(
+                        f"Could not decode response body from {path}: {e}"
+                    ) from e
                 logger.error("Error decoding json response: %s", e)
                 return []
 

test_rest/test_decode_errors.py

@@ -0,0 +1,46 @@
+from types import SimpleNamespace
+import unittest
+
+from massive import RESTClient
+from massive.exceptions import ResponseDecodeError
+
+TRUNCATED = b'{"results":[{"p":1.0,"s":100},{"p'
+
+
+def _decode_through_get_handler(client):
+    """Run a truncated body through the same try/except that _get and _paginate_iter use."""
+    resp = SimpleNamespace(data=TRUNCATED)
+    try:
+        return client._decode(resp)
+    except ValueError as e:
+        if client.raise_on_decode_error:
+            raise ResponseDecodeError(f"Could not decode response body: {e}") from e
+        return []
+
+
+class DecodeErrorTest(unittest.TestCase):
+    def test_default_returns_empty_result(self):
+        """Unchanged behaviour: an undecodable body is logged and becomes an empty result."""
+        c = RESTClient("")
+        self.assertFalse(c.raise_on_decode_error)
+        self.assertEqual(_decode_through_get_handler(c), [])
+
+    def test_opt_in_raises(self):
+        c = RESTClient("", raise_on_decode_error=True)
+        self.assertTrue(c.raise_on_decode_error)
+        with self.assertRaises(ResponseDecodeError):
+            _decode_through_get_handler(c)
+
+    def test_flag_reaches_the_vx_client(self):
+        c = RESTClient("", raise_on_decode_error=True)
+        self.assertTrue(c.vx.raise_on_decode_error)
+
+    def test_a_good_body_is_unaffected(self):
+        for flag in (False, True):
+            c = RESTClient("", raise_on_decode_error=flag)
+            resp = SimpleNamespace(data=b'{"results":[{"p":1.0}]}')
+            self.assertEqual(c._decode(resp), {"results": [{"p": 1.0}]})
+
+
+if __name__ == "__main__":
+    unittest.main()