[aaronrobertshaw]

Backport of Gutenberg PR WordPress/gutenberg#86337

Trac ticket: https://core.trac.wordpress.org/ticket/66485

Adds wp_get_block_supports_classes_and_styles(), which returns the combined classes and styles of the background, color, border, shadow and spacing helpers. An optional list limits it to the supports a block applies to one element.

This PR backports:

• wp_get_block_supports_classes_and_styles(), next to the other block support utilities,
• and the accompanying block supports tests.

The Avatar and Post Navigation Link changes that call it arrive later with the Gutenberg package update.

Dependency: stacked on #14094, which adds the five helpers this one calls. Once #14094 is committed, this branch should be rebased onto trunk.

Testing instructions

Nothing renders differently, because no block calls the helper in Core yet. To check its output:

npm run env:cli -- eval "var_export( wp_get_block_supports_classes_and_styles( array( 'borderColor' => 'contrast', 'style' => array( 'border' => array( 'width' => '2px' ), 'shadow' => 'var:preset|shadow|natural', 'spacing' => array( 'padding' => array( 'top' => '10px' ) ) ) ), array( 'border', 'shadow' ) ) );"

It outputs only the border and shadow, without the padding:

array (
  'class' => 'has-border-color has-contrast-border-color',
  'style' => 'border-width:2px;box-shadow:var(--wp--preset--shadow--natural);',
)

Without this PR the command fails with a fatal error for an undefined function.

Use of AI

AI assistance: Yes
Tool(s): Claude Code
Model(s): Claude Opus 5.5
Used for: the port from Gutenberg and the tests; I reviewed and edited them.

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Props aaronrobertshaw, westonruter.

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[ramonjd]

Backport is accurate. I smoke tested a bunch of blocks on the frontend, checked the CSS and classnames.

Tests pass locally.

Might be worth holding off until 7.2 is stable to avoid clashes?

Thanks!