block_has_support()

block_has_support( WP_Block_Type|null $block_type, string|array $feature, mixed $default_value = false ): bool

function block_has_support( $block_type, $feature, $default_value = false ) {
	$block_support = $default_value;
	if ( $block_type instanceof WP_Block_Type ) {
		if ( is_array( $feature ) && count( $feature ) === 1 ) {
			$feature = $feature[0];
		}

		if ( is_array( $feature ) ) {
			$block_support = _wp_array_get( $block_type->supports, $feature, $default_value );
		} elseif ( isset( $block_type->supports[ $feature ] ) ) {
			$block_support = $block_type->supports[ $feature ];
		}
	}

	return true === $block_support || is_array( $block_support );
}