Do not test sys_tmp_dir if cache dir is provided. Fix #65.

.laminas-ci.json

@@ -1,2 +1,12 @@
 {
+  "additional_checks": [
+    {
+      "name": "Unit tests with non existent TMPDIR",
+      "job": {
+        "php": "*",
+        "dependencies": "locked",
+        "command": "TMPDIR=nonexistent vendor/bin/phpunit test/unit/FilesystemOptionsNonExistentTmpdirTest.php"
+      }
+    }
+  ]
 }

src/FilesystemOptions.php

@@ -112,9 +112,11 @@ public function __construct($options = null)
             $this->dirPermission  = false;
         }
 
-        $this->setCacheDir(null);
-
         parent::__construct($options);
+
+        if ($this->cacheDir === null) {
+            $this->setCacheDir(null);
+        }
     }
 
     /**

test/unit/FilesystemOptionsNonExistentTmpdirTest.php

@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LaminasTest\Cache\Storage\Adapter;
+
+use Laminas\Cache\Storage\Adapter\FilesystemOptions;
+use PHPUnit\Framework\TestCase;
+
+use function is_writable;
+use function sys_get_temp_dir;
+
+final class FilesystemOptionsNonExistentTmpdirTest extends TestCase
+{
+    public function testWillNotWriteToSystemTempWhenCacheDirIsProvided(): void
+    {
+        if (is_writable(sys_get_temp_dir())) {
+            self::markTestSkipped('Test has to be executed with a non existent TMPDIR');
+        }
+
+        $option = new FilesystemOptions(['cacheDir' => '/./tmp']);
+        self::assertSame('/tmp', $option->getCacheDir());
+    }
+}

test/unit/FilesystemOptionsTest.php

@@ -55,6 +55,12 @@ protected function createAdapterOptions(): AdapterOptions
         return new FilesystemOptions();
     }
 
+    public function testSetCacheDirToSystemsTempDirWhenNoCacheDirIsProvided(): void
+    {
+        $options = new FilesystemOptions();
+        self::assertEquals(realpath(sys_get_temp_dir()), $options->getCacheDir());
+    }
+
     public function testSetCacheDirToSystemsTempDirWithNull(): void
     {
         $this->options->setCacheDir(null);