test: add test for Time::__toString()

Author: kenjis

tests/system/I18n/TimeTest.php

@@ -17,6 +17,7 @@
 use Config\App;
 use DateTime;
 use DateTimeZone;
+use Generator;
 use IntlDateFormatter;
 use Locale;
 
@@ -1138,4 +1139,25 @@ public function testSetTestNowWithFaLocale()
 
         Locale::setDefault($currentLocale);
     }
+
+    /**
+     * @dataProvider provideLocales
+     */
+    public function testToStringDoesNotDependOnLocale(string $locale)
+    {
+        Locale::setDefault($locale);
+
+        $time = new Time('2017/03/10 12:00');
+
+        $this->assertSame('2017-03-10 12:00:00', (string) $time);
+    }
+
+    public function provideLocales(): Generator
+    {
+        yield from [
+            ['en'],
+            ['de'],
+            ['fa'],
+        ];
+    }
 }