Bug 194337 – nomodule scripts are fetched in some cases (with empty cache or in new tab)

• Status: RESOLVED
• Resolution: FIXED
• Component: DOM

[Jakub G (dailymotion)]

Created attachment 361285 [details]
min repro HTML

Repro:

0. Open Safari (any version, including 12 or TP74; preferably 11+ to have `performance.getEntries()`)
1. Empty the browser cache (alt-cmd-e), or open a new tab (cmd-t)
2. Load https://jg-testpage.github.io/es-modules/module-nomodule/safari.html (also attached to this bug)
3. Observe that `nomodule.js` is listed as one of the loaded resources.

Expected:

3. `nomodule` scripts should never be loaded in a modern browser.

Additional notes:

- Reproducible about 50% of the time in new tab
- Reproducible 100% of the time when when the cache is empty
- When there's no "traditional" script on top of HTML that has neither "nomodule" nor "type=module", I didn't repro (so far)

Other browsers

- Chrome: not affected
- Firefox: not affected
- Edge: affected, but it has bigger problems (it always loads nomodule)

[Radar WebKit Bug Importer]

<rdar://problem/49700924>

[Ryosuke Niwa]

This is probably an issue with the HTML preloader.

[Yusuke Suzuki]

This is related to preloader.

[Yusuke Suzuki]

Created attachment 388501 [details]
Patch

[Yusuke Suzuki]

Comment on attachment 388501 [details]
Patch

Thanks!

[WebKit Commit Bot]

The commit-queue encountered the following flaky tests while processing attachment 388501 [details]:

editing/spelling/spellcheck-async-remove-frame.html bug 158401 (authors: [e-mail], [e-mail], and [e-mail])
The commit-queue is continuing to process your patch.

[WebKit Commit Bot]

Comment on attachment 388501 [details]
Patch

Clearing flags on attachment: 388501

Committed r254970: <https://trac.webkit.org/changeset/254970>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.