TS2339: Property 'getResponseHeader' does not exist on type 'XMLHttpRequestEventTarget'.

[monolithed]

var xhr = new XMLHttpRequest();

xhr.onload = function (event) {
        this.response // Not found
	this.getResponseHeader  // Not found
        // etc
};

index.ts(30,47): error TS2339: Property 'response' does not exist on type 'XMLHttpRequestEventTarget'.
index.ts(34,16): error TS2339: Property 'getResponseHeader' does not exist on type 'XMLHttpRequestEventTarget'.

[mhegazy]

this type for onload (as well as onerror, onabort, onloadend, onloadstart, onprogress and ontimeout) should be XMLHttpRequest.

[mhegazy]

PRs welcomed. You can find more information about contributing lib.d.ts fixes at https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md#contributing-libdts-fixes.