Better error message when theme.json styles use a duotone preset not in settings

[ajlende]

What?

Provides a more helpful error message when you've misspelled a duotone variable name or tried to use a variable that we don't have the duotone information to generate an SVG.

Why?

More clear error messages are more helpful for theme developers. And it's better to show a clear error than silently not render the filter since this problem exists within a hand-coded theme.json that a developer would be creating. Using the global styles UI shouldn't create this error because only presets are able to be selected from in the interface.

How?

Triggers a custom error message when the CSS var being used in styles isn't part of the presets defined in settings.

Testing Instructions

1. Update theme.json styles.blocks['core/image'].filter.duotone = var(--wp--preset--duotone--does-not-exist).
2. Add image block in the post editor.
3. See the new error message.

Testing Instructions for Keyboard

Screenshots or screencast

Before

Notice: Undefined index: wp-duotone-does-not-exist in /Users/ajlende/Documents/gutenberg/lib/class-wp-duotone-gutenberg.php on line 715

After

Notice: Function WP_Duotone_Gutenberg::enqueue_global_styles_preset was called <strong>incorrectly</strong>. The duotone id "wp-duotone-prmary" is not registered in theme.json settings Please see <a href="https://wordpress.org/documentation/article/debugging-in-wordpress/">Debugging in WordPress</a> for more information. (This message was added in version 6.3.0.) in /Users/ajlende/Documents/wordpress-develop/src/wp-includes/functions.php on line 5865

Previously, in this PR using trigger_error.

Notice: The duotone id "wp-duotone-does-not-exist" is not registered in theme.json settings in /Users/ajlende/Documents/gutenberg/lib/class-wp-duotone-gutenberg.php on line 718

[scruffian]

LGTM

[spacedmonkey]

Trigger error? Let's use _doing_it_wrong instead.

[ajlende]

I was under the impression that _doing_it_wrong was used for developers calling functions incorrectly. The function is being called correctly, but the theme.json it's reading from has bad data. Is it still the right choice in this case?

EDIT: For reference, this is what I was basing things off of which uses trigger_error. https://github.com/WordPress/gutenberg/blob/trunk/lib/class-wp-theme-json-resolver-gutenberg.php#L501

[ajlende]

I pushed up the change to use _doing_it_wrong, but I think that error message is worse. It now reads:

Notice: Function WP_Duotone_Gutenberg::enqueue_global_styles_preset was called <strong>incorrectly</strong>. The duotone id "wp-duotone-prmary" is not registered in theme.json settings Please see <a href="https://wordpress.org/documentation/article/debugging-in-wordpress/">Debugging in WordPress</a> for more information. (This message was added in version 6.3.0.) in /Users/ajlende/Documents/wordpress-develop/src/wp-includes/functions.php on line 5865

[github-actions]

Flaky tests detected in ef60cd5.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/5027636815
📝 Reported issues:

• [Flaky Test] should apply Heading block styles to all Heading blocks #49942 in /test/e2e/specs/site-editor/push-to-global-styles.spec.js
• [Flaky Test] should delete the template after saving the reverted template #50783 in /test/e2e/specs/site-editor/template-revert.spec.js
• [Flaky Test] should insert elements from multiple completers in a single block #47916 in /test/e2e/specs/editor/various/autocomplete-and-mentions.spec.js
• [Flaky Test] should show the original content after revert #47897 in /test/e2e/specs/site-editor/template-revert.spec.js