Split out confusing path combination logic to separate method (#21247)

* Split out confusing path combination logic to separate method

* Fix argument type

airflow/providers/http/hooks/http.py

@@ -113,10 +113,7 @@ def run(
 
         session = self.get_conn(headers)
 
-        if self.base_url and not self.base_url.endswith('/') and endpoint and not endpoint.startswith('/'):
-            url = self.base_url + '/' + endpoint
-        else:
-            url = (self.base_url or '') + (endpoint or '')
+        url = self.url_from_endpoint(endpoint)
 
         if self.method == 'GET':
             # GET uses params
@@ -215,6 +212,12 @@ def run_with_advanced_retry(self, _retry_args: Dict[Any, Any], *args: Any, **kwa
 
         return self._retry_obj(self.run, *args, **kwargs)
 
+    def url_from_endpoint(self, endpoint: Optional[str]) -> str:
+        """Combine base url with endpoint"""
+        if self.base_url and not self.base_url.endswith('/') and endpoint and not endpoint.startswith('/'):
+            return self.base_url + '/' + endpoint
+        return (self.base_url or '') + (endpoint or '')
+
     def test_connection(self):
         """Test HTTP Connection"""
         try: