Block editor fails to initialize when loading minified scripts

[azaozz]

Happens when SCRIPT_DEBUG = false. Seems the block-library.js file wasn't minified properly.

Throws these errors:

Uncaught SyntaxError: unexpected token: ':'       block-library.min.js:14:127081
Uncaught TypeError: i is undefined                edit-post.min.js:7:123891

Trac ticket: https://core.trac.wordpress.org/ticket/58660

I've overwritten the original change so that this PR excludes changes to the built PHP files that were originally present.

[ironprogrammer]

Test Report

Patch tested: ​https://github.com/WordPress/wordpress-develop/pull/4742

Steps to Reproduce or Test

1. Check out PR branch.
2. Run npm install && npm run build:dev.
3. In wp-config.php, set SCRIPT_DEBUG to false.
4. Load the editor in a post or site editor.

Expected Results

• ✅ The editor should load without error.

Environment

• Hardware: MacBook Pro Apple M1 Pro
• OS: macOS 13.4.1
• Browser: Safari 16.5.1, Google Chrome 114.0.5735.133
• Server: nginx/1.25.0
• PHP: 7.4.33
• WordPress: 6.3-alpha-56078-src

Actual Results

• ✅ Editor loads without PHP errors.

Additional Information

• The following JS warnings were logged in the console when SCRIPT_DEBUG is false:

DevTools failed to load source map: Could not load content for ​http://wp-src.test/wp-admin/hooks.js.map: Unexpected token '<', "<!DOCTYPE "... is not valid JSON

DevTools failed to load source map: Could not load content for ​http://wp-src.test/wp-includes/js/underscore-umd.js.map: Unexpected token '<', "<!DOCTYPE "... is not valid JSON

was added to the iframe incorrectly. Please use block.json or enqueue_block_assets to add styles to the iframe.
<link rel="stylesheet" href="http://wp-src.test/wp-admin/load-styles.php?c=0&amp;dir=ltr&amp;load%5Bchunk_0%5D=dashicons,admin-bar,wp-components,wp-block-editor,wp-reusable-blocks,wp-editor,common,forms,wp-reset-editor-styles,wp-block-libr&amp;load%5Bchunk_1%5D=ary,wp-block-editor-content,wp-edit-blocks,wp-edit-site,wp-format-library,buttons,media-views,wp-block-directory,admin-menu,dash&amp;load%5Bchunk_2%5D=board,list-tables,edit,revisions,media,themes,about,nav-menus,wp-pointer,widgets,site-icon,l10n,wp-auth-check&amp;ver=6.3-alpha-56078-src" media="all">

• When SCRIPT_DEBUG is set to true, only the underscore-umd.js.map notice remains.

[joemcgill]

In 56097:

Build/Test Tools: Update terser-webpack-plugin.

This bumps the terser-webpack-plugin dependency to version 5.3.9, which fixes an error during the minification process of the @wordpress/block-library package during builds.

Props clorith, azaozz, desrosj.
Fixes #58660, See #57657.

This was added in https://core.trac.wordpress.org/changeset/56097.