Delete empty terms in WP CLI

wpcli_delete_empty_terms.php

<?php

/**
 * Delete all empty terms for the given $taxonomy
 * PS: You can do the same in WP CLI or even plain WordPress php functions
 *
 * @param : string $tax : given taxonomy to work on
 * 
 * @author Maxime CULEA
 */
function delete_empty_terms( $tax = 'category' ) {
	$args               = [
		'taxonomy' => $tax,
		'fields'   => 'ids',
	];
	$term_ids_not_empty = get_terms( $args );
	if ( empty( $term_ids_not_empty ) ) {
		return;
	}

	$term_ids_empty = get_terms( wp_parse_args( $args, [
		'hide_empty' => false,
		'exclude'    => $term_ids_not_empty,
	] ) );
	if ( empty( $term_ids_empty ) ) {
		return;
	}

	foreach ( $term_ids_empty as $term_id ) {
		\WP_CLI::runcommand( sprintf( 'term delete %s %d', $tax, $term_id ), [ 'exit_error' => false ] );
	}

	\WP_CLI::runcommand( sprintf( 'term recount %s', $tax ), [ 'exit_error' => false ] );
}