Streaming downloads through a ServiceWorker work perfectly on macOS, but on iOS are shown as 0kb and do not report progress correctly in the download manager.
Run this project:
$ npx serve
$ open 'http://localhost:3000'Click the download link to download a .txt file created and streamed entirely from the registered ServiceWorker. The download is artificially slow to make it easier to see the progress in the download manager.
Expected outcome
The download manager reads the Content-length header and reports that as the file size, then shows the % progress correctly as the file is streamed.
Actual outcome
On iOS, the file size is reported as 0kb and the progress is shown as indeterminate until the download completes. The downloaded file is usable, so this is a cosmetic bug in the download manager. We have seen bug reports for our app where people mistook this cosmetic bug as a download failure.
On macOS the download manager does the right thing.
