Fixed microseconds being dropped when creating Time and FrozenTime from Chronos and DateTime instances.

src/I18n/DateFormatTrait.php

@@ -453,9 +453,9 @@ trait DateFormatTrait
     public function __debugInfo()
     {
         return [
-            'time' => $this->toIso8601String(),
+            'time' => $this->format('Y-m-d\TH:i:s.uP'),
             'timezone' => $this->getTimezone()->getName(),
-            'fixedNowTime' => static::hasTestNow() ? static::getTestNow()->toIso8601String() : false
+            'fixedNowTime' => static::hasTestNow() ? static::getTestNow()->format('Y-m-d\TH:i:s.uP') : false
         ];
     }
 }

src/I18n/FrozenTime.php

@@ -111,7 +111,7 @@ class FrozenTime extends Chronos implements JsonSerializable
     {
         if ($time instanceof DateTimeInterface) {
             $tz = $time->getTimezone();
-            $time = $time->format('Y-m-d H:i:s');
+            $time = $time->format('Y-m-d H:i:s.u');
         }
 
         if (is_numeric($time)) {

src/I18n/Time.php

@@ -109,7 +109,7 @@ class Time extends MutableDateTime implements JsonSerializable
     {
         if ($time instanceof DateTimeInterface) {
             $tz = $time->getTimezone();
-            $time = $time->format('Y-m-d H:i:s');
+            $time = $time->format('Y-m-d H:i:s.u');
         }
 
         if (is_numeric($time)) {

tests/TestCase/I18n/TimeTest.php

@@ -14,6 +14,7 @@
  */
 namespace Cake\Test\TestCase\I18n;
 
+use Cake\Chronos\Chronos;
 use Cake\I18n\FrozenTime;
 use Cake\I18n\I18n;
 use Cake\I18n\Time;
@@ -87,14 +88,22 @@ class TimeTest extends TestCase
      */
     public function testConstructFromAnotherInstance($class)
     {
-        $time = '2015-01-22 10:33:44';
+        $time = '2015-01-22 10:33:44.123456';
         $frozen = new FrozenTime($time, 'America/Chicago');
         $subject = new $class($frozen);
-        $this->assertEquals($time, $subject->format('Y-m-d H:i:s'), 'frozen time construction');
+        $this->assertEquals($time, $subject->format('Y-m-d H:i:s.u'), 'frozen time construction');
 
         $mut = new Time($time, 'America/Chicago');
         $subject = new $class($mut);
-        $this->assertEquals($time, $subject->format('Y-m-d H:i:s'), 'mutable time construction');
+        $this->assertEquals($time, $subject->format('Y-m-d H:i:s.u'), 'mutable time construction');
+
+        $mut = new Chronos($time, 'America/Chicago');
+        $subject = new $class($mut);
+        $this->assertEquals($time, $subject->format('Y-m-d H:i:s.u'), 'mutable time construction');
+
+        $mut = new \DateTime($time, new \DateTimeZone('America/Chicago'));
+        $subject = new $class($mut);
+        $this->assertEquals($time, $subject->format('Y-m-d H:i:s.u'), 'mutable time construction');
     }
 
     /**
@@ -780,9 +789,9 @@ class TimeTest extends TestCase
     {
         $time = new $class('2014-04-20 10:10:10');
         $expected = [
-            'time' => '2014-04-20T10:10:10+00:00',
+            'time' => '2014-04-20T10:10:10.000000+00:00',
             'timezone' => 'UTC',
-            'fixedNowTime' => $class::getTestNow()->toIso8601String()
+            'fixedNowTime' => $class::getTestNow()->format('Y-m-d\TH:i:s.uP')
         ];
         $this->assertEquals($expected, $time->__debugInfo());
     }