fix: S3 exists() should not match directories for file paths

Previously, exists() would incorrectly add a trailing slash to all paths,
causing file paths to match directories with the same prefix. This led to
exists('/path/to/file.html') returning true when only the directory
'/path/to/file.html/' existed, resulting in NoSuchKey errors when trying
to read the file.

Now, trailing slashes are only added if the original path ends with '/',
ensuring:
- exists('file.html') only returns true if the file exists
- exists('directory/') correctly checks for directory existence

Added test testFileExistsDoesNotMatchDirectoryPrefix() to verify the fix.

Author: ChiragAgg5k

src/Storage/Device/S3.php

@@ -636,8 +636,8 @@ public function exists(string $path): bool
                     $prefix = $root.'/'.ltrim($path, '/');
                 }
 
-                if (! empty($path) && ! str_ends_with($prefix, '/')) {
-                    $prefix .= '/';
+                if (! empty($path) && str_ends_with($path, '/')) {
+                    $prefix = rtrim($prefix, '/').'/';
                 }
 
                 $objects = $this->listObjects($prefix, 1);

tests/Storage/S3Base.php

@@ -165,6 +165,25 @@ public function testDirectoryExists()
         $this->assertEquals(false, $this->object->exists($this->object->getPath('nested/deep/structure')));
     }
 
+    /**
+     * Test that file paths without trailing slash don't incorrectly match directories
+     * Verifies fix: exists('file.html') should not return true when directory 'file.html/' exists
+     */
+    public function testFileExistsDoesNotMatchDirectoryPrefix()
+    {
+        $this->object->write($this->object->getPath('builds/index.html'), 'content', 'text/html');
+        $this->object->write($this->object->getPath('builds/other.css'), 'body {}', 'text/css');
+
+        $this->assertEquals(true, $this->object->exists($this->object->getPath('builds/index.html')));
+
+        $this->object->delete($this->object->getPath('builds/index.html'));
+
+        // File should not exist even though directory 'builds/' still contains other.css
+        $this->assertEquals(false, $this->object->exists($this->object->getPath('builds/index.html')));
+
+        $this->object->delete($this->object->getPath('builds/other.css'));
+    }
+
     public function testMove()
     {
         $this->assertEquals(true, $this->object->write($this->object->getPath('text-for-move.txt'), 'Hello World', 'text/plain'));