Author like get posts

author-posts.php

<?php

private static function tax_query_name_like( $taxonomy, $term ) {
	global $wpdb;
	$statement = $wpdb->prepare(
	"
	SELECT	term_taxonomy_id
	FROM	$wpdb->terms
	JOIN	$wpdb->term_taxonomy
	USING	(term_id)
	WHERE	name
	LIKE	%s
	AND		taxonomy = %s
	", '%' . $term . '%', $taxonomy );
	return $wpdb->get_col( $statement );
}

public static function pre_get_posts( $query ) {

	/* @var $author_like string Retorna o nome do autor, caso o usuario tenha usado a busca avancada */
	$author_like		 = filter_input( INPUT_GET, 'author_like', FILTER_SANITIZE_STRING );
	/* @var $author_query_string string As palavras-chave da busca normal ou o nome do autor da avancada */
	$author_query_string = empty( $author_like ) ? get_search_query() : $author_like;
	/* @var $term_ids array Um vetor com os IDs de todos os autores que possuam nome parecido com o buscado */
	$term_ids			 = static::tax_query_name_like( 'author', $author_query_string );

	if ( count( $term_ids ) > 0 ) {
		$author_query_args = array(
			array(
				'taxonomy'			 => 'author',
				'field'				 => 'term_id',
				'include_children'	 => false,
				'operator'			 => 'IN',
				'terms'				 => $term_ids
			)
		);
		$query->set( 'tax_query', $author_query_args );
	}
	return $query;
}