Abort every in-flight chunk when a chunked upload is canceled

[enyo]

Fixes #2366.

The bug

_uploadData stores its request on the file:

for (let file of files) {
  file.xhr = xhr;
}

With parallelChunkUploads that runs once per concurrent chunk, so file.xhr ends up holding whichever request started last. cancelUpload aborts only that one:

if (typeof file.xhr !== "undefined") {
  file.xhr.abort();
}

Cancel a 3-way parallel chunked upload and two of the three requests keep streaming to the server. They are silent about it: files[0].status is already CANCELED, so _finishedUploading and _handleUploadError both return early and nothing is emitted. The user's bandwidth keeps going, and the server keeps receiving chunks for a file the UI says was canceled. Worse, if that last chunk had already completed, file.xhr points at a finished request and abort() does nothing at all while the others are still live.

The fix

Each chunk already carries its own xhr (file.upload.chunks[i].xhr, set in _uploadData and cleared on success), so cancelUpload walks the chunks and aborts the ones still UPLOADING, marking them CANCELED. Non-chunked uploads keep aborting file.xhr exactly as before.

Test

should abort every chunk still in flight when the upload is canceled starts a 6-chunk upload with parallelChunkUploads: 3 and cancels it. Against main the assertion reads expected [ false, false, true ] to deeply equal [ true, true, true ] — the reported behaviour, exactly.

One thing I noticed but did not touch

cancelUpload opens with this._getFilesWithXhr(file.xhr!). When a file is canceled during the _transformFiles window it is already UPLOADING but has no xhr yet, so that call matches every file whose xhr is still undefined — i.e. every queued file — and marks them all CANCELED with a canceled event each. That is a separate bug from the one reported here, so I left it alone; happy to do it in its own PR.

[github-actions]

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	79.51%	885 / 1113
🔵	Statements	79.86%	932 / 1167
🔵	Functions	92.89%	196 / 211
🔵	Branches	76.77%	519 / 676

File Coverage

File	Stmts	Branches	Functions	Lines	Uncovered Lines
Changed Files
packages/dropzone/src/dropzone.ts	77.52%	75.26%	92.63%	77.04%	233, 243, 268, 274-277, 334, 361, 404-405, 464, 572, 594, 613-614, 721, 744-747, 784-786, 816-819, 842, 988, 1016, 1045, 1049, 1121-1122, 1154, 1164-1166, 1183-1184, 1190-1223, 1348, 1406, 1455-1456, 1584, 1608-1609, 1663, 1697, 1717-1748, 1756, 1770-1774, 1785, 1798-1803, 1816-1817, 1821-1822, 1840-1841, 1919-1934, 1979, 1995, 2166-2168, 2203, 2213, 2246-2280, 2287-2388, 2397-2400

Generated in workflow #140 for commit 536d94a by the Vitest Coverage Report Action