Introduce Parameter Object Refactor | After Refactor

CustomerRefactored.php

<?php

use DateRange;
/**
 * Easy to read
 * Easy to refactor
 * Easy to mock and test
 */
class Customer {

    function amountInvoicedIn(DateRange $d_range) {
        
    }

    function amountReceicedIn(DateRange $d_range) {
        
    }

    function amountOverdueIn(DateRange $d_range) {
        
    }

}

DateRange.php

<?php

class DateRange {

    private $end_date;
    private $start_date;

    function __construct($start_date, $end_date) {
        $this->start_date = $start_date;
        $this->end_date = $end_date;
    }

    function getStartDate() {
        return $this->start_date;
    }

    function getEndDate() {
        return $this->end_date;
    }

}

DateRangeChild.php

<?php

/**
 * Someone (probably your future self) mercilessly murdering your design in the name of
 * pretty time
 *
 * @author jacob
 */
class DateRangeChild  extends DateRange{
    function getStartDate() {
        $this->start_date;
        return $this->makePretty($date);
    }
    function makePretty($date){
        return "Today is {$date}";
    }
}

DateRangeProtected.php

<?php

/**
 * A parameter object safe from murder
 *
 * @author jacob
 */
final class DateRangeProtected {

    protected $end_date;
    protected $start_date;

    function __construct($start_date, $end_date) {
        $this->start_date = $start_date;
        $this->end_date = $end_date;
    }

    function getStartDate() {
        return $this->start_date;
    }

    function getEndDate() {
        return $this->end_date;
    }

}