tests: added more coverage

Author: ddevsr

tests/system/HTTP/CURLRequestTest.php

@@ -1236,11 +1236,21 @@ public static function provideDNSCacheTimeout(): iterable
                 'expectedHasKey' => true,
                 'expectedValue'  => 0,
             ],
+            'valid timeout (zero / disabled using string)' => [
+                'input'          => '0',
+                'expectedHasKey' => true,
+                'expectedValue'  => 0,
+            ],
             'valid timeout (forever)' => [
                 'input'          => -1,
                 'expectedHasKey' => true,
                 'expectedValue'  => -1,
             ],
+            'valid timeout (forever using string)' => [
+                'input'          => '-1',
+                'expectedHasKey' => true,
+                'expectedValue'  => -1,
+            ],
             'invalid timeout (null)' => [
                 'input'          => null,
                 'expectedHasKey' => false,