Fix spatie#73 and support immutable dates

composer.json

@@ -39,5 +39,5 @@
     },
     "config": {
         "sort-packages": true
-  }
+    }
 }

src/OpeningHours.php

@@ -4,6 +4,7 @@
 
 use DateTime;
 use DateTimeZone;
+use DateTimeImmutable;
 use DateTimeInterface;
 use Spatie\OpeningHours\Helpers\Arr;
 use Spatie\OpeningHours\Exceptions\Exception;
@@ -150,13 +151,20 @@ public function isClosed(): bool
         return $this->isClosedAt(new DateTime());
     }
 
+    /**
+     * @TODO This should returns DateTimeInterface on next major release
+     */
     public function nextOpen(DateTimeInterface $dateTime): DateTime
     {
+        if (! ($dateTime instanceof DateTimeImmutable)) {
+            $dateTime = clone $dateTime;
+        }
+
         $openingHoursForDay = $this->forDate($dateTime);
         $nextOpen = $openingHoursForDay->nextOpen(Time::fromDateTime($dateTime));
 
-        while ($nextOpen == false) {
-            $dateTime
+        while ($nextOpen === false) {
+            $dateTime = $dateTime
                 ->modify('+1 day')
                 ->setTime(0, 0, 0);
 
@@ -166,18 +174,25 @@ public function nextOpen(DateTimeInterface $dateTime): DateTime
         }
 
         $nextDateTime = $nextOpen->toDateTime();
-        $dateTime->setTime($nextDateTime->format('G'), $nextDateTime->format('i'), 0);
+        $dateTime = $dateTime->setTime($nextDateTime->format('G'), $nextDateTime->format('i'), 0);
 
         return $dateTime;
     }
 
+    /**
+     * @TODO This should returns DateTimeInterface on next major release
+     */
     public function nextClose(DateTimeInterface $dateTime): DateTime
     {
+        if (! ($dateTime instanceof DateTimeImmutable)) {
+            $dateTime = clone $dateTime;
+        }
+
         $openingHoursForDay = $this->forDate($dateTime);
         $nextClose = $openingHoursForDay->nextClose(Time::fromDateTime($dateTime));
 
-        while ($nextClose == false) {
-            $dateTime
+        while ($nextClose === false) {
+            $dateTime = $dateTime
                 ->modify('+1 day')
                 ->setTime(0, 0, 0);
 
@@ -187,7 +202,7 @@ public function nextClose(DateTimeInterface $dateTime): DateTime
         }
 
         $nextDateTime = $nextClose->toDateTime();
-        $dateTime->setTime($nextDateTime->format('G'), $nextDateTime->format('i'), 0);
+        $dateTime = $dateTime->setTime($nextDateTime->format('G'), $nextDateTime->format('i'), 0);
 
         return $dateTime;
     }

src/OpeningHoursForDay.php

@@ -44,10 +44,14 @@ public function nextOpen(Time $time)
     {
         foreach ($this->openingHours as $timeRange) {
             if ($nextOpen = $this->findNextOpenInWorkingHours($time, $timeRange)) {
+                reset($timeRange);
+
                 return $nextOpen;
             }
 
             if ($nextOpen = $this->findNextOpenInFreeTime($time, $timeRange)) {
+                reset($timeRange);
+
                 return $nextOpen;
             }
         }
@@ -59,10 +63,14 @@ public function nextClose(Time $time)
     {
         foreach ($this->openingHours as $timeRange) {
             if ($nextClose = $this->findNextCloseInWorkingHours($time, $timeRange)) {
+                reset($timeRange);
+
                 return $nextClose;
             }
 
             if ($nextClose = $this->findNextCloseInFreeTime($time, $timeRange)) {
+                reset($timeRange);
+
                 return $nextClose;
             }
         }

src/Time.php

@@ -3,6 +3,7 @@
 namespace Spatie\OpeningHours;
 
 use DateTime;
+use DateTimeImmutable;
 use DateTimeInterface;
 use Spatie\OpeningHours\Exceptions\InvalidTimeString;
 
@@ -83,9 +84,16 @@ public function diff(self $time): \DateInterval
         return $this->toDateTime()->diff($time->toDateTime());
     }
 
+    /**
+     * @TODO This should returns DateTime on next major release
+     */
     public function toDateTime(DateTime $date = null): DateTime
     {
-        $date = $date ? (clone $date) : new DateTime('1970-01-01 00:00:00');
+        if (! $date) {
+            $date = new DateTime('1970-01-01 00:00:00');
+        } elseif (! ($date instanceof DateTimeImmutable)) {
+            $date = clone $date;
+        }
 
         return $date->setTime($this->hours, $this->minutes);
     }

tests/OpeningHoursFillTest.php

@@ -3,6 +3,7 @@
 namespace Spatie\OpeningHours\Test;
 
 use DateTime;
+use DateTimeImmutable;
 use Spatie\OpeningHours\Day;
 use PHPUnit\Framework\TestCase;
 use Spatie\OpeningHours\TimeRange;
@@ -44,6 +45,7 @@ public function it_fills_opening_hours()
         $this->assertEquals((string) $openingHours->forDay('friday')[0], '09:00-20:00');
 
         $this->assertCount(0, $openingHours->forDate(new DateTime('2016-09-26 11:00:00')));
+        $this->assertCount(0, $openingHours->forDate(new DateTimeImmutable('2016-09-26 11:00:00')));
     }
 
     /** @test */

tests/OpeningHoursForDayTest.php

@@ -71,7 +71,7 @@ public function it_can_unset_offset()
     }
 
     /** @test */
-    public function ic_can_get_iterator()
+    public function it_can_get_iterator()
     {
         $openingHoursForDay = OpeningHoursForDay::fromStrings(['09:00-12:00', '13:00-18:00']);