feat: add csv() modifier (#316)

* fix: cast to correct type

* feat: add csv() modifier

* chore: export SingleRequestBuilder

* chore: write tests for csv()

* 'Refactored by Sourcery' (#317)

Co-authored-by: Sourcery AI <>

---------

Co-authored-by: sourcery-ai[bot] <58596630+sourcery-ai[bot]@users.noreply.github.com>

Author: anand2312

postgrest/__init__.py

@@ -10,13 +10,15 @@
     AsyncQueryRequestBuilder,
     AsyncRequestBuilder,
     AsyncSelectRequestBuilder,
+    AsyncSingleRequestBuilder,
 )
 from ._sync.client import SyncPostgrestClient
 from ._sync.request_builder import (
     SyncFilterRequestBuilder,
     SyncQueryRequestBuilder,
     SyncRequestBuilder,
     SyncSelectRequestBuilder,
+    SyncSingleRequestBuilder,
 )
 from .base_request_builder import APIResponse
 from .constants import DEFAULT_POSTGREST_CLIENT_HEADERS

postgrest/_async/request_builder.py

@@ -252,6 +252,18 @@ def text_search(
             session=self.session,  # type: ignore
         )
 
+    def csv(self) -> AsyncSingleRequestBuilder[str]:
+        """Specify that the query must retrieve data as a single CSV string."""
+        self.headers["Accept"] = "text/csv"
+        return AsyncSingleRequestBuilder[str](
+            session=self.session,  # type: ignore
+            path=self.path,
+            http_method=self.http_method,
+            headers=self.headers,
+            params=self.params,
+            json=self.json,
+        )
+
 
 class AsyncRequestBuilder(Generic[_ReturnT]):
     def __init__(self, session: AsyncClient, path: str) -> None:

postgrest/_sync/request_builder.py

@@ -252,6 +252,18 @@ def text_search(
             session=self.session,  # type: ignore
         )
 
+    def csv(self) -> SyncSingleRequestBuilder[str]:
+        """Specify that the query must retrieve data as a single CSV string."""
+        self.headers["Accept"] = "text/csv"
+        return SyncSingleRequestBuilder[str](
+            session=self.session,  # type: ignore
+            path=self.path,
+            http_method=self.http_method,
+            headers=self.headers,
+            params=self.params,
+            json=self.json,
+        )
+
 
 class SyncRequestBuilder(Generic[_ReturnT]):
     def __init__(self, session: SyncClient, path: str) -> None:

postgrest/base_request_builder.py

@@ -34,7 +34,7 @@
     from pydantic import validator as field_validator
 
 from .types import CountMethod, Filters, RequestMethod, ReturnMethod
-from .utils import AsyncClient, SyncClient, sanitize_param
+from .utils import AsyncClient, SyncClient, get_origin_and_cast, sanitize_param
 
 
 class QueryArgs(NamedTuple):
@@ -200,8 +200,11 @@ class SingleAPIResponse(APIResponse[_ReturnT], Generic[_ReturnT]):
     def from_http_request_response(
         cls: Type[Self], request_response: RequestResponse
     ) -> Self:
-        data = request_response.json()
         count = cls._get_count_from_http_request_response(request_response)
+        try:
+            data = request_response.json()
+        except JSONDecodeError:
+            data = request_response.text if len(request_response.text) > 0 else []
         return cls[_ReturnT](data=data, count=count)  # type: ignore
 
     @classmethod
@@ -420,7 +423,7 @@ def __init__(
         # Generic[T] is an instance of typing._GenericAlias, so doing Generic[T].__init__
         # tries to call _GenericAlias.__init__ - which is the wrong method
         # The __origin__ attribute of the _GenericAlias is the actual class
-        BaseFilterRequestBuilder[_ReturnT].__origin__.__init__(
+        get_origin_and_cast(BaseFilterRequestBuilder[_ReturnT]).__init__(
             self, session, headers, params
         )
 

tests/_async/test_request_builder.py

@@ -3,7 +3,7 @@
 import pytest
 from httpx import Request, Response
 
-from postgrest import AsyncRequestBuilder
+from postgrest import AsyncRequestBuilder, AsyncSingleRequestBuilder
 from postgrest.base_request_builder import APIResponse, SingleAPIResponse
 from postgrest.types import CountMethod
 from postgrest.utils import AsyncClient
@@ -36,6 +36,12 @@ def test_select_with_count(self, request_builder: AsyncRequestBuilder):
         assert builder.http_method == "HEAD"
         assert builder.json == {}
 
+    def test_select_as_csv(self, request_builder: AsyncRequestBuilder):
+        builder = request_builder.select("*").csv()
+
+        assert builder.headers["Accept"] == "text/csv"
+        assert isinstance(builder, AsyncSingleRequestBuilder)
+
 
 class TestInsert:
     def test_insert(self, request_builder: AsyncRequestBuilder):
@@ -146,6 +152,11 @@ def test_explain_options(self, request_builder: AsyncRequestBuilder):
         )
 
 
+@pytest.fixture
+def csv_api_response() -> str:
+    return "id,name\n1,foo\n"
+
+
 @pytest.fixture
 def api_response_with_error() -> Dict[str, Any]:
     return {
@@ -281,6 +292,15 @@ def request_response_with_single_data(
     )
 
 
+@pytest.fixture
+def request_response_with_csv_data(csv_api_response: str) -> Response:
+    return Response(
+        status_code=200,
+        text=csv_api_response,
+        request=Request(method="GET", url="http://example.com"),
+    )
+
+
 class TestApiResponse:
     def test_response_raises_when_api_error(
         self, api_response_with_error: Dict[str, Any]
@@ -374,3 +394,12 @@ def test_single_from_http_request_response_constructor(
         assert isinstance(result.data, dict)
         assert result.data == single_api_response
         assert result.count == 2
+
+    def test_single_with_csv_data(
+        self, request_response_with_csv_data: Response, csv_api_response: str
+    ):
+        result = SingleAPIResponse.from_http_request_response(
+            request_response_with_csv_data
+        )
+        assert isinstance(result.data, str)
+        assert result.data == csv_api_response

tests/_sync/test_request_builder.py

@@ -3,7 +3,7 @@
 import pytest
 from httpx import Request, Response
 
-from postgrest import SyncRequestBuilder
+from postgrest import SyncRequestBuilder, SyncSingleRequestBuilder
 from postgrest.base_request_builder import APIResponse, SingleAPIResponse
 from postgrest.types import CountMethod
 from postgrest.utils import SyncClient
@@ -36,6 +36,12 @@ def test_select_with_count(self, request_builder: SyncRequestBuilder):
         assert builder.http_method == "HEAD"
         assert builder.json == {}
 
+    def test_select_as_csv(self, request_builder: SyncRequestBuilder):
+        builder = request_builder.select("*").csv()
+
+        assert builder.headers["Accept"] == "text/csv"
+        assert isinstance(builder, SyncSingleRequestBuilder)
+
 
 class TestInsert:
     def test_insert(self, request_builder: SyncRequestBuilder):
@@ -146,6 +152,11 @@ def test_explain_options(self, request_builder: SyncRequestBuilder):
         )
 
 
+@pytest.fixture
+def csv_api_response() -> str:
+    return "id,name\n1,foo\n"
+
+
 @pytest.fixture
 def api_response_with_error() -> Dict[str, Any]:
     return {
@@ -281,6 +292,15 @@ def request_response_with_single_data(
     )
 
 
+@pytest.fixture
+def request_response_with_csv_data(csv_api_response: str) -> Response:
+    return Response(
+        status_code=200,
+        text=csv_api_response,
+        request=Request(method="GET", url="http://example.com"),
+    )
+
+
 class TestApiResponse:
     def test_response_raises_when_api_error(
         self, api_response_with_error: Dict[str, Any]
@@ -374,3 +394,12 @@ def test_single_from_http_request_response_constructor(
         assert isinstance(result.data, dict)
         assert result.data == single_api_response
         assert result.count == 2
+
+    def test_single_with_csv_data(
+        self, request_response_with_csv_data: Response, csv_api_response: str
+    ):
+        result = SingleAPIResponse.from_http_request_response(
+            request_response_with_csv_data
+        )
+        assert isinstance(result.data, str)
+        assert result.data == csv_api_response