chore(API): validate JSON input for APIError.__init__()

directly passing `r.json()` into APIError.__init__() is incorrect, as
it expects a `Dict[str, str]`. instead, it should first validate that
the json object is in fact the correct schema, by using a pydantic model

postgrest/_async/request_builder.py

@@ -19,7 +19,7 @@
     pre_update,
     pre_upsert,
 )
-from ..exceptions import APIError, generate_default_error_message
+from ..exceptions import APIError, APIErrorFromJSON, generate_default_error_message
 from ..types import ReturnMethod
 from ..utils import AsyncClient, get_origin_and_cast
 
@@ -75,10 +75,9 @@ async def execute(self) -> APIResponse[_ReturnT]:
                             return body
                 return APIResponse[_ReturnT].from_http_request_response(r)
             else:
-                raise APIError(r.json())
+                json_obj = APIErrorFromJSON.model_validate_json(r.content)
+                raise APIError(dict(json_obj))
         except ValidationError as e:
-            raise APIError(r.json()) from e
-        except JSONDecodeError:
             raise APIError(generate_default_error_message(r))
 
 
@@ -124,10 +123,9 @@ async def execute(self) -> SingleAPIResponse[_ReturnT]:
             ):  # Response.ok from JS (https://developer.mozilla.org/en-US/docs/Web/API/Response/ok)
                 return SingleAPIResponse[_ReturnT].from_http_request_response(r)
             else:
-                raise APIError(r.json())
+                json_obj = APIErrorFromJSON.model_validate_json(r.content)
+                raise APIError(dict(json_obj))
         except ValidationError as e:
-            raise APIError(r.json()) from e
-        except JSONDecodeError:
             raise APIError(generate_default_error_message(r))
 
 

postgrest/exceptions.py

@@ -1,6 +1,21 @@
 from typing import Dict, Optional
+from pydantic import BaseModel
 
 
+class APIErrorFromJSON(BaseModel):
+    """
+    A pydantic object to validate an error info object
+    from a json string.
+    """
+    message: Optional[str]
+    """The error message."""
+    code: Optional[str]
+    """The error code."""
+    hint: Optional[str]
+    """The error hint."""
+    details: Optional[str]
+    """The error details."""
+
 class APIError(Exception):
     """
     Base exception for all API errors.

tests/_async/test_client.py

@@ -1,7 +1,7 @@
 from unittest.mock import patch
 
 import pytest
-from httpx import BasicAuth, Headers
+from httpx import BasicAuth, Headers, Response, Request
 
 from postgrest import AsyncPostgrestClient
 from postgrest.exceptions import APIError
@@ -107,7 +107,6 @@ async def test_response_status_code_outside_ok(postgrest_client: AsyncPostgrestC
         )
         assert exc_response["errors"][0].get("code") == 400
 
-
 @pytest.mark.asyncio
 async def test_response_maybe_single(postgrest_client: AsyncPostgrestClient):
     with patch(
@@ -127,3 +126,27 @@ async def test_response_maybe_single(postgrest_client: AsyncPostgrestClient):
         exc_response = exc_info.value.json()
         assert isinstance(exc_response.get("message"), str)
         assert "code" in exc_response and int(exc_response["code"]) == 204
+
+# https://github.com/supabase/postgrest-py/issues/595
+@pytest.mark.asyncio
+async def test_response_client_invalid_response_but_valid_json(postgrest_client: AsyncPostgrestClient):
+    with patch(
+        "httpx._client.AsyncClient.request",
+        return_value=Response(
+            status_code=502,
+            text='"gateway error: Error: Network connection lost."', # quotes makes this text a valid non-dict JSON object
+            request=Request(method="GET", url="http://example.com")
+        )
+    ):
+        client = (
+            postgrest_client.from_("test").select("a", "b").eq("c", "d").single()
+        )
+        assert "Accept" in client.headers
+        assert client.headers.get("Accept") == "application/vnd.pgrst.object+json"
+        with pytest.raises(APIError) as exc_info:
+            await client.execute()
+        assert isinstance(exc_info, pytest.ExceptionInfo)
+        exc_response = exc_info.value.json()
+        assert isinstance(exc_response.get("message"), str)
+        assert exc_response.get("message") == "JSON could not be generated"
+        assert "code" in exc_response and int(exc_response["code"]) == 502