RequestConfiguration instances share the same HeadersCollection instance by default

[jackmpcollins]

The default for RequestConfiguration.headers is an instance of HeadersCollection. This is created at class definition time, meaning that all instances of RequestConfiguration share the same instance of HeadersCollection by default. This leads to conflict when different instances of RequestConfiguration add/remove headers.

kiota-python/packages/abstractions/kiota_abstractions/base_request_configuration.py

Lines 16 to 22 in 806c946

	@dataclass
	class RequestConfiguration(Generic[QueryParameters]):
	"""
	Configuration for the request such as headers, query parameters, and middleware options.
	"""
	# Request headers
	headers: HeadersCollection = HeadersCollection()

Instead, a factory should be used so that a new instance is created:

from dataclasses import dataclass, field
from typing import Generic, Optional, TypeVar

QueryParameters = TypeVar("QueryParameters")

@dataclass
class RequestConfiguration(Generic[QueryParameters]):
    headers: HeadersCollection = field(default_factory=HeadersCollection)
    options: Optional[list[RequestOption]] = None
    query_parameters: Optional[QueryParameters] = None

The same/similar issue also affects HeadersInspectionHandlerOption init param defaults.

kiota-python/packages/http/httpx/kiota_http/middleware/options/headers_inspection_handler_option.py

Lines 10 to 20 in 806c946

	class HeadersInspectionHandlerOption(RequestOption):
	"""Config options for the HeaderInspectionHandler"""
	HEADERS_INSPECTION_HANDLER_OPTION_KEY = "HeadersInspectionHandlerOption"
	def __init__(
	self,
	inspect_request_headers: bool = True,
	inspect_response_headers: bool = True,
	request_headers: HeadersCollection = HeadersCollection(),
	response_headers: HeadersCollection = HeadersCollection(),