Split packages and blocks into separate Weback configs

[desrosj]

This was originally attempted in [51259] on #53397, but there were some issues that warranted a revert before packaging 5.8 RC1 (see [51268]).

​WordPress/wordpress-develop-1412 was used to build the patch applied in [51259]. From @gziolo on that PR:

We need to add handling for JavaScript files that are going to be used with blocks on the frontend. They don't work quite well with the current setup for entry points created for packages because of reasons like

• the output path is different
• frontend scripts should not be exposed under wp globals

In general, it looks like the split is a good strategy because it nicely separates two independents parts: packages and blocks. There isn't that much overlap between configs anyway.

After committing, the following notice was seen in Core when visiting a page with a core/file block:

Notice: register_block_script_handle was called incorrectly. The asset file for the "viewScript" defined in "core/file" block definition is missing. Please see Debugging in WordPress for more information. (This message was added in version 5.5.0.) in /var/www/src/wp-includes/functions.php on line 5535

An attempt was made to fix this in [51267]. This appeared to fix the issue when visiting the site. However, ​automated tests still displayed the notice, and it ​caused failures in some environments. This was also reverted.

​Gutenberg-33082 was opened as a follow up to the attempted fix, but after looking further, the lines being changed may have an intentional reason to be how they are.

[SergeyBiryukov]

Just noting that I'm currently seeing these notices in WordPress trunk with Gutenberg 11.2.1 active:

Notice: register_block_script_handle was called incorrectly. The asset file for the "viewScript" defined in "core/file" block definition is missing. Please see Debugging in WordPress for more information. (This message was added in version 5.5.0.) in S:\home\wordpress.test\develop\build\wp-includes\functions.php on line 5537

Notice: register_block_script_handle was called incorrectly. The asset file for the "viewScript" defined in "core/navigation" block definition is missing. Please see Debugging in WordPress for more information. (This message was added in version 5.5.0.) in S:\home\wordpress.test\develop\build\wp-includes\functions.php on line 5537

It looks like core/file and core/navigation are the only two blocks that have a viewScript defined:

"viewScript": "file:./view.min.js"

Pretty much like in comment:44:ticket:53397, I've tracked this down to register_block_script_handle():

• $script_asset_path is assigned the value returned by realpath() on this path: S:\home\wordpress.test\develop\build\wp-content\plugins\gutenberg\build\block-library\blocks/file/./view.min.asset.php
• realpath() returns false, because the file does not exist.
• The file_exists() check below also returns false.

[gziolo]

The bug report shared by @SergeyBiryukov should be fixed in #55311.

[gziolo]

By the way, this issue can be closed because we were able to split the webpack config in WordPress 5.9 release cycle. Relate commit [51501]. Related track issue #53690.

[SergeyBiryukov]

Replying to gziolo:

The bug report shared by @SergeyBiryukov should be fixed in #55311.

Perfect, thanks!

Seems like this one can be closed as a duplicate of #53690 then.