refactor: move the request call to the backend (#2413)

gitlab/client.py

@@ -752,7 +752,7 @@ def http_request(
         cur_retries = 0
         while True:
             try:
-                result = self.session.request(
+                result = self.http_backend.http_request(
                     method=verb,
                     url=url,
                     json=json,

gitlab/http_backends/requests_backend.py

@@ -1,6 +1,7 @@
-from typing import Optional
+from typing import Any, Dict, Optional, Union
 
 import requests
+from requests_toolbelt.multipart.encoder import MultipartEncoder  # type: ignore
 
 
 class RequestsBackend:
@@ -10,3 +11,43 @@ def __init__(self, session: Optional[requests.Session] = None) -> None:
     @property
     def client(self) -> requests.Session:
         return self._client
+
+    def http_request(
+        self,
+        method: str,
+        url: str,
+        json: Optional[Union[Dict[str, Any], bytes]] = None,
+        data: Optional[Union[Dict[str, Any], MultipartEncoder]] = None,
+        params: Optional[Any] = None,
+        timeout: Optional[float] = None,
+        verify: Optional[Union[bool, str]] = True,
+        stream: Optional[bool] = False,
+        **kwargs: Any
+    ) -> requests.Response:
+        """Make HTTP request
+
+        Args:
+            method: The HTTP method to call ('get', 'post', 'put', 'delete', etc.)
+            url: The full URL
+            data: The data to send to the server in the body of the request
+            json: Data to send in the body in json by default
+            timeout: The timeout, in seconds, for the request
+            verify: Whether SSL certificates should be validated. If
+                the value is a string, it is the path to a CA file used for
+                certificate validation.
+            stream: Whether the data should be streamed
+
+        Returns:
+            A requests Response object.
+        """
+        return self._client.request(
+            method=method,
+            url=url,
+            params=params,
+            data=data,
+            timeout=timeout,
+            stream=stream,
+            verify=verify,
+            json=json,
+            **kwargs
+        )