diff --git a/src/utils/__tests__/PhutilUtilsTestCase.php b/src/utils/__tests__/PhutilUtilsTestCase.php
--- a/src/utils/__tests__/PhutilUtilsTestCase.php
+++ b/src/utils/__tests__/PhutilUtilsTestCase.php
@@ -1070,4 +1070,20 @@
     }
   }
 
+
+  public function testStringCasting() {
+    $map = array(
+      array(123, '123', 'number'),
+      array(null, '', 'null to empty string'),
+      array('text', 'text', 'string'),
+    );
+
+    foreach ($map as $test_case) {
+      list($input, $expected_output, $test_name) = $test_case;
+
+      $actual = phutil_string_cast($input);
+
+      $this->assertEqual($expected_output, $actual, $test_name);
+    }
+  }
 }