fix(postgrest): send rpc list args as array literals on GET and HEAD (#1752)

Author: hsusul

src/postgrest/src/postgrest/_async/client.py

@@ -15,6 +15,7 @@
     DEFAULT_POSTGREST_CLIENT_TIMEOUT,
 )
 from ..types import CountMethod
+from ..utils import rpc_query_param
 from ..version import __version__
 from .request_builder import (
     AsyncRequestBuilder,
@@ -181,7 +182,7 @@ def rpc(
         headers.update(self.headers)
         # the params here are params to be sent to the RPC and not the queryparams!
         json, http_params = (
-            ({}, QueryParams(params))
+            ({}, QueryParams({k: rpc_query_param(v) for k, v in params.items()}))
             if method in ("HEAD", "GET")
             else (params, QueryParams())
         )

src/postgrest/src/postgrest/_sync/client.py

@@ -15,6 +15,7 @@
     DEFAULT_POSTGREST_CLIENT_TIMEOUT,
 )
 from ..types import CountMethod
+from ..utils import rpc_query_param
 from ..version import __version__
 from .request_builder import (
     RequestConfig,
@@ -181,7 +182,7 @@ def rpc(
         headers.update(self.headers)
         # the params here are params to be sent to the RPC and not the queryparams!
         json, http_params = (
-            ({}, QueryParams(params))
+            ({}, QueryParams({k: rpc_query_param(v) for k, v in params.items()}))
             if method in ("HEAD", "GET")
             else (params, QueryParams())
         )

src/postgrest/src/postgrest/utils.py

@@ -71,6 +71,17 @@ def sanitize_pattern_param(pattern: str) -> str:
     return sanitize_param(pattern.replace("%", "*"))
 
 
+def rpc_query_param(value: Any) -> Any:
+    """Format an RPC argument sent in the query string, as in GET or HEAD calls.
+
+    Lists and tuples become PostgreSQL array literals, since PostgREST keeps only
+    one value when a non-variadic argument is repeated.
+    """
+    if isinstance(value, (list, tuple)):
+        return f"{{{','.join(str(v) for v in value)}}}"
+    return value
+
+
 def is_http_url(url: URL) -> bool:
     return url.scheme in {"https", "http"}
 

src/postgrest/tests/_async/test_client.py

@@ -1,4 +1,5 @@
 import re
+from typing import Any
 from unittest.mock import patch
 
 import pytest
@@ -176,3 +177,14 @@ async def test_response_client_invalid_response_but_valid_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
+
+
+@pytest.mark.parametrize("head", [False, True])
+def test_rpc_query_params_send_lists_as_array_literals(
+    postgrest_client: AsyncPostgrestClient, head: bool
+):
+    params: Any = {"ids": [1, 2, 3], "name": "x"}
+    builder = postgrest_client.rpc("sum_ids", params, head=head, get=not head)
+
+    assert builder.request.params.get_list("ids") == ["{1,2,3}"]
+    assert builder.request.params["name"] == "x"

src/postgrest/tests/_sync/test_client.py

@@ -1,4 +1,5 @@
 import re
+from typing import Any
 from unittest.mock import patch
 
 import pytest
@@ -174,3 +175,14 @@ def test_response_client_invalid_response_but_valid_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
+
+
+@pytest.mark.parametrize("head", [False, True])
+def test_rpc_query_params_send_lists_as_array_literals(
+    postgrest_client: SyncPostgrestClient, head: bool
+):
+    params: Any = {"ids": [1, 2, 3], "name": "x"}
+    builder = postgrest_client.rpc("sum_ids", params, head=head, get=not head)
+
+    assert builder.request.params.get_list("ids") == ["{1,2,3}"]
+    assert builder.request.params["name"] == "x"