From c1ae9715b7e9f31007c82bd90cac70cca2284b20 Mon Sep 17 00:00:00 2001
From: Samuel Gordalina <samuel.gordalina@gmail.com>
Date: Fri, 28 Jul 2023 11:20:33 -1000
Subject: [PATCH] Write file to temp dir to ensure it is writable

Fixes #230
---
 src/CacheTool.php       | 17 ++++++++++++++++-
 tests/CacheToolTest.php |  5 +++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/CacheTool.php b/src/CacheTool.php
index f6f6333..4789329 100644
--- a/src/CacheTool.php
+++ b/src/CacheTool.php
@@ -235,7 +235,7 @@ protected function getWritableTempDir($tempDir = null) {
         if (is_null($tempDir)) {
             $tempDirs = ['/dev/shm', '/var/run', sys_get_temp_dir()];
             foreach ($tempDirs as $dir) {
-                if (is_dir($dir) && is_writable($dir)) {
+                if ($this->isWritable($dir)) {
                     $tempDir = $dir;
                     break;
                 }
@@ -248,4 +248,19 @@ protected function getWritableTempDir($tempDir = null) {
 
         return $tempDir;
     }
+
+    protected function isWritable($tempDir) {
+        if (!is_dir($tempDir) || !is_writable($tempDir)) {
+            return false;
+        }
+
+        $tempFile = tempnam($tempDir, 'cachetool-test');
+
+        if ($tempFile === false) {
+            return false;
+        }
+
+        @unlink($tempFile);
+        return true;
+    }
 }
diff --git a/tests/CacheToolTest.php b/tests/CacheToolTest.php
index c2106c1..579eeb3 100644
--- a/tests/CacheToolTest.php
+++ b/tests/CacheToolTest.php
@@ -74,6 +74,11 @@ public function testWithInexistentTempDir() {
         rmdir($dir);
     }
 
+    public function testWithExistentTempDir() {
+        $cachetool = new CacheTool(null);
+        $this->assertDirectoryExists($cachetool->getTempDir());
+    }
+
     public function testWithSetAdapterAndLogger()
     {
         $logger = $this->getLogger();