RESTClient: implement AuthConfigBase.__bool__ + update docs (#1413)

* Fix AuthConfigBase so its instances always evaluate to True in bool context; change docs to suggest direct inheritance from AuthBase

* Add tests

* Fix formatting

* uses AuthBase as auth type

---------

Co-authored-by: Anton Burnashev <[email protected]>

Author: rudolfix

dlt/sources/helpers/rest_client/auth.py

@@ -38,7 +38,11 @@ class AuthConfigBase(AuthBase, CredentialsConfiguration):
     configurable via env variables or toml files
     """
 
-    pass
+    def __bool__(self) -> bool:
+        # This is needed to avoid AuthConfigBase-derived classes
+        # which do not implement CredentialsConfiguration interface
+        # to be evaluated as False in requests.sessions.Session.prepare_request()
+        return True
 
 
 @configspec

dlt/sources/helpers/rest_client/client.py

@@ -6,12 +6,14 @@
     Any,
     TypeVar,
     Iterable,
+    Union,
     cast,
 )
 import copy
 from urllib.parse import urlparse
 from requests import Session as BaseSession  # noqa: I251
 from requests import Response, Request
+from requests.auth import AuthBase
 
 from dlt.common import jsonpath, logger
 
@@ -41,7 +43,7 @@ def __init__(
         request: Request,
         response: Response,
         paginator: BasePaginator,
-        auth: AuthConfigBase,
+        auth: AuthBase,
     ):
         super().__init__(__iterable)
         self.request = request
@@ -57,7 +59,7 @@ class RESTClient:
     Args:
         base_url (str): The base URL of the API to make requests to.
         headers (Optional[Dict[str, str]]): Default headers to include in all requests.
-        auth (Optional[AuthConfigBase]): Authentication configuration for all requests.
+        auth (Optional[AuthBase]): Authentication configuration for all requests.
         paginator (Optional[BasePaginator]): Default paginator for handling paginated responses.
         data_selector (Optional[jsonpath.TJsonPath]): JSONPath selector for extracting data from responses.
         session (BaseSession): HTTP session for making requests.
@@ -69,7 +71,7 @@ def __init__(
         self,
         base_url: str,
         headers: Optional[Dict[str, str]] = None,
-        auth: Optional[AuthConfigBase] = None,
+        auth: Optional[AuthBase] = None,
         paginator: Optional[BasePaginator] = None,
         data_selector: Optional[jsonpath.TJsonPath] = None,
         session: BaseSession = None,
@@ -105,7 +107,7 @@ def _create_request(
         method: HTTPMethod,
         params: Dict[str, Any],
         json: Optional[Dict[str, Any]] = None,
-        auth: Optional[AuthConfigBase] = None,
+        auth: Optional[AuthBase] = None,
         hooks: Optional[Hooks] = None,
     ) -> Request:
         parsed_url = urlparse(path)
@@ -154,7 +156,7 @@ def paginate(
         method: HTTPMethodBasic = "GET",
         params: Optional[Dict[str, Any]] = None,
         json: Optional[Dict[str, Any]] = None,
-        auth: Optional[AuthConfigBase] = None,
+        auth: Optional[AuthBase] = None,
         paginator: Optional[BasePaginator] = None,
         data_selector: Optional[jsonpath.TJsonPath] = None,
         hooks: Optional[Hooks] = None,
@@ -166,7 +168,7 @@ def paginate(
             method (HTTPMethodBasic): HTTP method for the request, defaults to 'get'.
             params (Optional[Dict[str, Any]]): URL parameters for the request.
             json (Optional[Dict[str, Any]]): JSON payload for the request.
-            auth (Optional[AuthConfigBase]): Authentication configuration for the request.
+            auth (Optional[AuthBase): Authentication configuration for the request.
             paginator (Optional[BasePaginator]): Paginator instance for handling
                 pagination logic.
             data_selector (Optional[jsonpath.TJsonPath]): JSONPath selector for

docs/website/docs/general-usage/http/rest-client.md

@@ -407,7 +407,7 @@ The available authentication methods are defined in the `dlt.sources.helpers.res
 - [APIKeyAuth](#api-key-authentication)
 - [HttpBasicAuth](#http-basic-authentication)
 
-For specific use cases, you can [implement custom authentication](#implementing-custom-authentication) by subclassing the `AuthConfigBase` class.
+For specific use cases, you can [implement custom authentication](#implementing-custom-authentication) by subclassing the `AuthBase` class from the Requests library.
 
 ### Bearer token authentication
 
@@ -479,12 +479,12 @@ response = client.get("/protected/resource")
 
 ### Implementing custom authentication
 
-You can implement custom authentication by subclassing the `AuthConfigBase` class and implementing the `__call__` method:
+You can implement custom authentication by subclassing the `AuthBase` class and implementing the `__call__` method:
 
 ```py
-from dlt.sources.helpers.rest_client.auth import AuthConfigBase
+from requests.auth import AuthBase
 
-class CustomAuth(AuthConfigBase):
+class CustomAuth(AuthBase):
     def __init__(self, token):
         self.token = token
 

tests/sources/helpers/rest_client/test_client.py

@@ -1,8 +1,10 @@
 import os
 import pytest
 from typing import Any, cast
+from requests import PreparedRequest, Request
+from requests.auth import AuthBase
 from dlt.common.typing import TSecretStrValue
-from dlt.sources.helpers.requests import Response, Request
+from dlt.sources.helpers.requests import Response
 from dlt.sources.helpers.rest_client import RESTClient
 from dlt.sources.helpers.rest_client.client import Hooks
 from dlt.sources.helpers.rest_client.paginators import JSONResponsePaginator
@@ -57,7 +59,6 @@ def test_page_context(self, rest_client: RESTClient) -> None:
         for page in rest_client.paginate(
             "/posts",
             paginator=JSONResponsePaginator(next_url_path="next_page"),
-            auth=AuthConfigBase(),
         ):
             # response that produced data
             assert isinstance(page.response, Response)
@@ -183,3 +184,44 @@ def test_oauth_jwt_auth_success(self, rest_client: RESTClient):
         )
 
         assert_pagination(list(pages_iter))
+
+    def test_custom_auth_success(self, rest_client: RESTClient):
+        class CustomAuthConfigBase(AuthConfigBase):
+            def __init__(self, token: str):
+                self.token = token
+
+            def __call__(self, request: PreparedRequest) -> PreparedRequest:
+                request.headers["Authorization"] = f"Bearer {self.token}"
+                return request
+
+        class CustomAuthAuthBase(AuthBase):
+            def __init__(self, token: str):
+                self.token = token
+
+            def __call__(self, request: PreparedRequest) -> PreparedRequest:
+                request.headers["Authorization"] = f"Bearer {self.token}"
+                return request
+
+        auth_list = [
+            CustomAuthConfigBase("test-token"),
+            CustomAuthAuthBase("test-token"),
+        ]
+
+        for auth in auth_list:
+            response = rest_client.get(
+                "/protected/posts/bearer-token",
+                auth=auth,
+            )
+
+            assert response.status_code == 200
+            assert response.json()["data"][0] == {"id": 0, "title": "Post 0"}
+
+            pages_iter = rest_client.paginate(
+                "/protected/posts/bearer-token",
+                auth=auth,
+            )
+
+            pages_list = list(pages_iter)
+            assert_pagination(pages_list)
+
+            assert pages_list[0].response.request.headers["Authorization"] == "Bearer test-token"