XMLHttpRequest abort() behavior and event triggering in IE10

In Internet Explorer 10, managing the lifecycle of asynchronous HTTP requests requires manual handling of the XMLHttpRequest object, as the modern AbortController API is unavailable. While the .abort() method is the documented way to terminate a pending request, there is uncertainty regarding the resulting event sequence.

The goal is to implement a consistent cancellation pattern that distinguishes between a user-initiated abort and a network-level failure. Depending on the current readyState of the request, calling .abort() may trigger different callbacks, potentially leading to redundant error handling logic.

• Does calling .abort() consistently trigger the onerror event in IE10 across all request states?
• Which readyState value is assigned to the request immediately following an abort operation?