From a0b08c607308c8f4f0298f796cf53958f7f6fbe3 Mon Sep 17 00:00:00 2001
From: DemeritCowboy <demeritcowboy@hotmail.com>
Date: Mon, 12 Aug 2019 17:44:57 -0400
Subject: [PATCH] demonstrate isNull

---
 tests/phpunit/CRM/Utils/SystemTest.php | 64 ++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/tests/phpunit/CRM/Utils/SystemTest.php b/tests/phpunit/CRM/Utils/SystemTest.php
index 602184984ee9..ea129b0fbae3 100644
--- a/tests/phpunit/CRM/Utils/SystemTest.php
+++ b/tests/phpunit/CRM/Utils/SystemTest.php
@@ -114,4 +114,68 @@ public function getURLs() {
     ];
   }
 
+  /**
+   * Demonstrate the, um, "flexibility" of isNull
+   */
+  public function testIsNull() {
+    $this->assertTrue(CRM_Utils_System::isNull(NULL));
+    $this->assertTrue(CRM_Utils_System::isNull(''));
+    $this->assertTrue(CRM_Utils_System::isNull('null'));
+    // Not sure how to test this one because phpunit itself throws an error.
+    // $this->assertTrue(CRM_Utils_System::isNull($someUnsetVariable));
+
+    // but...
+    $this->assertFalse(CRM_Utils_System::isNull('NULL'));
+    $this->assertFalse(CRM_Utils_System::isNull('Null'));
+
+    // probably ok?
+    $this->assertTrue(CRM_Utils_System::isNull([]));
+
+    // ok
+    $this->assertFalse(CRM_Utils_System::isNull(0));
+
+    // sure
+    $arr = [
+      1 => NULL,
+    ];
+    $this->assertTrue(CRM_Utils_System::isNull($arr[1]));
+    $this->assertTrue(CRM_Utils_System::isNull($arr));
+
+    // but then a little confusing
+    $arr = [
+      'IN' => NULL,
+    ];
+    $this->assertFalse(CRM_Utils_System::isNull($arr));
+
+    // now just guessing
+    $obj = new StdClass();
+    $this->assertFalse(CRM_Utils_System::isNull($obj));
+    $obj->anything = NULL;
+    $this->assertFalse(CRM_Utils_System::isNull($obj));
+
+    // this is ok
+    $arr = [
+      1 => [
+        'foo' => 'bar',
+      ],
+      2 => [
+        'a' => NULL,
+      ],
+    ];
+    $this->assertFalse(CRM_Utils_System::isNull($arr));
+
+    $arr = [
+      1 => $obj,
+    ];
+    $this->assertFalse(CRM_Utils_System::isNull($arr));
+
+    // sure
+    $arr = [
+      1 => NULL,
+      2 => '',
+      3 => 'null',
+    ];
+    $this->assertTrue(CRM_Utils_System::isNull($arr));
+  }
+
 }