v7: ajax: include progress events in return type

[OliverJAsh]

Bug Report

Current Behavior
Extracted from PR comment: #6001 (comment)

import { ajax } from 'rxjs/ajax';

// Expected return type: Observable<AjaxUploadProgressEvents | AjaxDownloadCompleteEvent | AjaxResponse<T>>
// Actual return type: Observable<AjaxResponse<unknown>>
const ob$ = ajax({
    method: 'POST',
    url: 'https://httpbin.org/post',
    includeUploadProgress: true,
});

ob$.subscribe(value => {
    // Expected type: AjaxUploadProgressEvents | AjaxDownloadCompleteEvent | AjaxResponse<T>
    // Actual type: AjaxResponse<unknown>
    value;
})

Expected behavior
See comments in code above.

Reproduction
See above.

[cartant]

@benlesh Beyond the includeUploadProgress-related types, there are types mentioned in the docs that don't exist (AjaxProgressEvents and AjaxDownloadCompleteEvent):

rxjs/src/internal/ajax/types.ts

Lines 181 to 188 in 105bf99

	/**
	* If `true`, will emit all download progress and load complete events as {@link AjaxProgressEvents}
	* from the observable. The final download event will also be emitted as a {@link AjaxDownloadCompleteEvent}
	*
	* If both this and {@link includeUploadProgress} are `false`, then only the {@link AjaxResponse} will
	* be emitted from the resulting observable.
	*/
	includeDownloadProgress?: boolean;

and the docs for includeUploadProgress mention download events, etc.:

rxjs/src/internal/ajax/types.ts

Lines 190 to 197 in 105bf99

	/**
	* If `true`, will emit all upload progress and load complete events as {@link AjaxUploadProgressEvents}
	* from the observable. The final download event will also be emitted as a {@link AjaxDownloadCompleteEvent}
	*
	* If both this and {@link includeDownloadProgress} are `false`, then only the {@link AjaxResponse} will
	* be emitted from the resulting observable.
	*/
	includeUploadProgress?: boolean;

[benlesh]

This merged PR is related: #6233

[cartant]

AFAICT, the consumer always receives an AjaxResponse and the type of the response can be inspected to see whether it's a progress event or whatever.

rxjs/src/internal/ajax/ajax.ts

Lines 409 to 417 in 6ef2725

	/**
	* Creates a response object to emit to the consumer.
	* @param direction the direction related to the event. Prefixes the event `type` in the
	* `AjaxResponse` object with "upload_" for events related to uploading and "download_"
	* for events related to downloading.
	* @param event the actual event object.
	*/
	const createResponse = (direction: AjaxDirection, event: ProgressEvent) =>
	new AjaxResponse<T>(event, xhr, _request, `${direction}_${event.type}`);

rxjs/src/internal/ajax/AjaxResponse.ts

Lines 80 to 93 in 6ef2725

	/**
	* The event type. This can be used to discern between different events
	* if you're using progress events with {@link includeDownloadProgress} or
	* {@link includeUploadProgress} settings in {@link AjaxConfig}.
	*
	* The event type consists of two parts: the {@link AjaxDirection} and the
	* the event type. Merged with `_`, they form the `type` string. The
	* direction can be an `upload` or a `download` direction, while an event can
	* be `loadstart`, `progress` or `load`.
	*
	* `download_load` is the type of event when download has finished and the
	* response is available.
	*/
	public readonly type: string = 'download_load'

However, I've ascertained this by reading the code. The ajax observable is something that I've not used in a long while. I'm guessing this can be closed now?

[OliverJAsh]

Ah, this comment is what lead me to believe the observable could emit types other than AjaxResponse.

https://github.com/ReactiveX/rxjs/pull/6001/files#diff-3345eb17e0a6c80853bd0dfb6dd88d6775cc0dac8c5a4bd4d7113942db4ddfa6R191-R195

It looks like that comment has since been updated: 40206e5#diff-3345eb17e0a6c80853bd0dfb6dd88d6775cc0dac8c5a4bd4d7113942db4ddfa6L182

I'll close this 😄