order_by_nulls.php

<?php

use Illuminate\Database\Query\Builder;

Builder::macro('orderByNulls', function ($column, $direction = 'asc', $nulls = 'last', $bindings = []) {
    $column = $this->getGrammar()->wrap($column);
    $direction = strtolower($direction) === 'asc' ? 'asc' : 'desc';
    $nulls = strtolower($nulls) === 'first' ? 'NULLS FIRST' : 'NULLS LAST';
    return $this->orderByRaw("$column $direction $nulls", $bindings);
});

Builder::macro('orderByNullsLast', function ($column, $direction = 'asc', $bindings = []) {
    return $this->orderByNulls($column, $direction, 'last', $bindings);
});

Builder::macro('orderByNullsFirst', function ($column, $direction = 'asc', $bindings = []) {
    return $this->orderByNulls($column, $direction, 'first', $bindings);
});