Scripts and styles enqueued before wp_enqueue_scripts fail to get sources identified

[westonruter]

Bug Description

Scripts and stylesheets enqueued at init do not get sourcing information. The same goes for assets registered at wp_default_styles and wp_scripts.

See demo plugin which demonstrates the issue.

(Additionally, inline styles added via wp_add_inline_style() do not get their source attributed.)

The wp-includes source is erroneous for 2 scripts and 3 stylesheets shown on the page.

Related: #4134

Expected Behaviour

The source column should indicate the theme/plugin that is actually responsible for the style or script being added to the page.

The case of the inline stylesheet is a tricky one, since it is one stylesheet with multiple sources. At the very least it should have the same source information as the stylesheet it is being added inline for. Best case is for it to include all themes/plugins that added inline styles to it.

Steps to reproduce

0. Enable Standard or Transitional mode in the AMP plugin.
1. Activate the above plugin
2. Validate a page.
3. Notice the wp-includes mentioned unexpectedly.

Screenshots

When active (and #4026 checked out) the validated URL screen looks like the following, with the red entries erroneously saying they are from wp-includes when they should actually be from “Add Assets before wp_enqueue_scripts”.

Additional context

• WordPress version:
• Plugin version:
• Gutenberg plugin version (if applicable):
• AMP plugin template mode:
• PHP version:
• OS:
• Browser: [e.g. chrome, safari]
• Device: [e.g. iPhone6]

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Acceptance criteria

Implementation brief

• This may be resolved simply by adding the validation hooks earlier. Origination is also a solution, perhaps long-term.

QA testing instructions

Demo

Changelog entry

[csossi]

@kienstra , can you do a dev QA check on this one (or shoot instructions my way?)

[kienstra]

Works as expected

Now, scripts enqueued on the init action get their source.

Similar to the test in #4134 (comment):

// Enqueues a script and stylesheet.
add_action(
	'init',
	function() {
		$script_slug = 'amp-scratchpad-script';
		wp_enqueue_script(
			$script_slug,
			plugins_url( 'script.js', __FILE__ ),
			[ 'jquery' ],
			'0.1',
			true
		);

		wp_localize_script(
			$script_slug,
			'ampScratchpad',
			wp_json_encode( [ 'foo' => 'baz' ] )
		);

		wp_add_inline_script(
			$script_slug,
			'doSomethingHere()'
		);

		$style_slug = 'amp-scratchpad-style';
		wp_enqueue_style(
			$style_slug,
			plugins_url( 'style.css', __FILE__ ),
			[ 'wp-color-picker', 'site-icon' ],
			'0.1'
		);

		wp_add_inline_style(
			$style_slug,
			'body { background-color: #ffffff; }'
		);
	}
);

...the source now appears:

Before, it was wp-includes, as Weston mentioned.