test: restore changed locale in tearDown()

Author: kenjis

tests/system/I18n/TimeDifferenceTest.php

@@ -19,14 +19,25 @@
  */
 final class TimeDifferenceTest extends CIUnitTestCase
 {
+    private string $currentLocale;
+
     protected function setUp(): void
     {
         parent::setUp();
 
         helper('date');
+
+        $this->currentLocale = Locale::getDefault();
         Locale::setDefault('America/Chicago');
     }
 
+    protected function tearDown(): void
+    {
+        parent::tearDown();
+
+        Locale::setDefault($this->currentLocale);
+    }
+
     public function testDifferenceBasics()
     {
         $current = Time::parse('March 10, 2017', 'America/Chicago');

tests/system/I18n/TimeTest.php

@@ -25,14 +25,25 @@
  */
 final class TimeTest extends CIUnitTestCase
 {
+    private string $currentLocale;
+
     protected function setUp(): void
     {
         parent::setUp();
 
         helper('date');
+
+        $this->currentLocale = Locale::getDefault();
         Locale::setDefault('en_US');
     }
 
+    protected function tearDown(): void
+    {
+        parent::tearDown();
+
+        Locale::setDefault($this->currentLocale);
+    }
+
     public function testNewTimeNow()
     {
         $formatter = new IntlDateFormatter(