TYPO3 Core

Do I have to specifiy anything anyhwere else besides the JavaScriptModules.php ?

The change to ES6-style JS for ext:form (#96568) was BEFORE the tags were introduced (#96710). So I think that the tag code messed something up

• $pageRenderer->getJavaScriptRenderer()->includeTaggedImports('tag-whatever'); (if a tag is present in JavaScriptModules.php)
• <f:be.pageRenderer includeJavaScriptModules="{0: '@typo3/package/whatever.js'}"/> (if no tags are present in JavaScriptModules.php )

ext:form does none of them.

It also seems strange that ext:form registers its own JS files with the tag 'backend.contextmenu' - sounds like a hack to me to workaround similar problems as discribed in this issue (adding this tag to my extension does not work , I tried it).

Patch set 1 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/80175

Thanks for your report, can confirm.
Fixed with the following patch https://review.typo3.org/c/Packages/TYPO3.CMS/+/80174 – please test.

Regarding some statements:

I think I found the cause / solution. With #96710 tagged imports where introduced. But it seems this change was not forwarded into ext:form.
The change to ES6-style JS for ext:form (#96568) was BEFORE the tags were introduced (#96710). So I think that the tag code messed something up

Yes, right, adding a (or two) tags for these "dynamic" imports would be an option, and I thought about adding one, but:
The dynamic module in EXT:form aren't dynamic at all, as they are all loaded on startup, so I decided/proposed to just preload them.
(Instead of preloading them we could have also just included them in the importmap, but that would require new API and preload is fine IMO)

Tags where actually thought for modules that are loaded late – due to ajax request – but that's not the case with EXT:form javascript modules.

I'd expect that adding an explicit JavaScript instruction also means that the required files are then loaded implicitly, automatically, without the need to tell again via tags.
Is there ever a case when I want to have a JavaScriptModuleInstruction without having the relevant JS files passed to the rendering by the ImportMap ?

I understand your "frustration", but we don't want object creations to have side effects – for that reason a created object doesn't auto-register itself.
It was simply an oversight, that the modules weren't actually loaded by PHP code, but only later by JS.

Not sure what the original intenion by the authors was on how this JavaScript stuff should be used in the end.

Please consider your tone. No one has "bad" intentions, bugs happen.

It also seems strange that ext:form registers its own JS files with the tag 'backend.contextmenu' - sounds like a hack to me to workaround similar problems as discribed in this issue (adding this tag to my extension does not work , I tried it).

This is another case and the tag `backend.contextmenu` was added to EXT:form importmap because it registers a context-menu item provider (for files).
But it turns out that the provider is based on the EXT:filellist provider and therefore doesn't require own javascript (`@typo3/filelist/context-menu-actions` is used). So this tag can actually be removed. I created a separate issue and patch for that:
https://forge.typo3.org/issues/101445
https://review.typo3.org/c/Packages/TYPO3.CMS/+/80176

Thanks for the explanations and the fix.

Please consider your tone. No one has "bad" intentions, bugs happen.

Where was I using the word "bad"? Please consider not interpreting an insult/rant into a neutral question by an outsider/none-core-dev of how a brand-new API is meant to be used.

Ok, sorry.

Patch set 2 for branch 12.4 of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/80174