1471602 - Appcache does not work in combination with Javascript module (ES6)

Status: RESOLVED DUPLICATE of bug 687758

(Core :: Networking: Cache, defect)

Description

[Benjamin Klaus]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:60.0) Gecko/20100101 Firefox/60.0
Build ID: 20180605171542

Steps to reproduce:

- go to https://asterics.github.io/AsTeRICS-Ergo-Grid/package/static/
- site with blue grid with words appears
- go offline
- refresh the page (F5)
- page is broken, no blue grid anymore
- error message in console: failed to load module "https://asterics.github.io/AsTeRICS-Ergo-Grid/package/static/build/asterics-grid.bundle.js"


Actual results:

the page does not work offline, but it should work because it uses AppCache (see https://developer.mozilla.org/de/docs/Web/HTML/Using_the_application_cache).


Expected results:

Page should work offline in the same way as offline.
Tested this in:
- Chrome 67.0.3396.87
- Edge 41.16299.492.0 / 16.16299
- IE 11.492

In all other browsers the page also works offline, Firefox is the only exception.

Comment 1

[Peter Magyari (Desktop QA)]

Hi,

I've managed to reproduce this issue on Windows Pro (64-bit) using Firefox 60.0 (2018-06-05)(64-bit), Firefox 61.0 (2018-06-21)(64-bit), Firefox Beta 62.0b3 (2018-06-28)(64-bit) and Firefox 63.0a1 (2018-07-01)(64-bit).

Thanks for reporting.

Comment 2

[Michal Novotny [:michal]]

Honza, can you please have a look at it and decide whether this is something we want to fix?

Comment 3

[Honza Bambas (:mayhemer)]

The script is being loaded as anonymous (=cookie-less and in a different namespace) thanks the "module" type.  We don't cache anonymous requests in appcache unless cross-origin.

This is a combo of bug 687758 and bug 1285476 (sec issue).

This issue is actually a spec problem of appcache (no instructions for how to handle anonymous loads).  I believe this is duplicate of bug 687758 - wontfix.

Appcache is an old and buggy technology.  We encourage to use Service Workers instead.

Comment 4

[Benjamin Klaus]

ok, thanks for the info. Service workers however are not supported at all in IE, so I would have to drop IE support (maybe I should do).

Comment 5

[Honza Bambas (:mayhemer)]

Other option could be to serve the script from a different domain, so that it will be cached in appcache duplicated in the anonymous namespace.

Comment 6

[Benjamin Klaus]

Ok, serving from other domain is currently not possible, but thanks for the hint.

>> This issue is actually a spec problem of appcache (no instructions for how to handle anonymous loads). <<
However, many other browsers (I've tested Chrome, Edge, IE) seem to implement it differently.

Comment 7

[Honza Bambas (:mayhemer)]

(In reply to Benjamin Klaus from comment #6)
> However, many other browsers (I've tested Chrome, Edge, IE) seem to
> implement it differently.

We do behave differently, because the default behavior is considered a security risk, see bug 1285476