Fix: TypeError when Message::make() is called after an implicit reconnect

src/Client.php

@@ -400,13 +400,20 @@ public function isConnected(): bool {
      * @throws ResponseException
      */
     public function checkConnection(): bool {
+        $active_folder = $this->active_folder;
         try {
             if (!$this->isConnected()) {
                 $this->connect();
+                if ($active_folder !== null) {
+                    $this->openFolder($active_folder, true);
+                }
                 return true;
             }
         } catch (\Throwable) {
             $this->connect();
+            if ($active_folder !== null) {
+                $this->openFolder($active_folder, true);
+            }
         }
         return false;
     }

src/Message.php

@@ -130,10 +130,8 @@ class Message {
 
     /**
      * The message folder path
-     *
-     * @var string $folder_path
      */
-    protected string $folder_path;
+    protected string $folder_path = '';
 
     /**
      * Fetch body options
@@ -297,11 +295,11 @@ public static function make(int $uid, ?int $msglist, Client $client, string $raw
                                  "message" => $client->getDefaultEvents("message"),
                                  "flag"    => $client->getDefaultEvents("flag"),
                              ]);
+        $instance->setClient($client);
         $instance->setFolderPath($client->getFolderPath());
         $instance->setSequence($sequence);
         $instance->setFetchOption($fetch_options);
 
-        $instance->setClient($client);
         $instance->setSequenceId($uid, $msglist);
 
         $instance->parseRawHeader($raw_header);
@@ -1465,11 +1463,21 @@ public function getFolderPath(): string {
 
     /**
      * Set the message path aka folder path
-     * @param $folder_path
+     * @param ?string $folder_path
      *
      * @return Message
      */
-    public function setFolderPath($folder_path): Message {
+    public function setFolderPath(?string $folder_path): Message {
+        if ($folder_path === null || $folder_path === '') {
+            $folder_path = $this->client?->getFolderPath();
+        }
+        if ($folder_path === null || $folder_path === '') {
+            $folder_path = (string)$this->config->get('options.common_folders.inbox', 'INBOX');
+        }
+        if ($folder_path === '') {
+            $folder_path = 'INBOX';
+        }
+
         $this->folder_path = $folder_path;
 
         return $this;

tests/issues/PR621Test.php

@@ -0,0 +1,66 @@
+<?php
+
+namespace Tests;
+
+use PHPUnit\Framework\TestCase;
+use ReflectionClass;
+use Webklex\PHPIMAP\Client;
+use Webklex\PHPIMAP\Config;
+use Webklex\PHPIMAP\Message;
+use Webklex\PHPIMAP\Connection\Protocols\ImapProtocol;
+
+/**
+ * @see https://github.com/Webklex/php-imap/pull/621
+ */
+class PR619Test extends TestCase
+{
+    private function makeClientWithNullActiveFolder(): Client
+    {
+        $config = Config::make([
+            'accounts' => [
+                'default' => [
+                    'host'       => 'localhost',
+                    'protocol'   => 'imap',
+                    'encryption' => 'ssl',
+                    'username'   => 'foo@example.com',
+                    'password'   => 'secret',
+                ],
+            ],
+        ]);
+
+        $client = new Client($config);
+
+        $protocol = $this->createStub(ImapProtocol::class);
+        $protocol->method('connected')->willReturn(true);
+        $client->connection = $protocol;
+
+        // Simulate the state after an implicit reconnect:
+        // Client::connect() always calls disconnect() first,
+        // and disconnect() resets active_folder to null.
+        $ref = new ReflectionClass($client);
+        $prop = $ref->getProperty('active_folder');
+        $prop->setAccessible(true);
+        $prop->setValue($client, null);
+
+        return $client;
+    }
+
+    public function testMakeThrowsTypeErrorWhenActiveFolderIsNull(): void
+    {
+        $this->expectException(\TypeError::class);
+
+        $client = $this->makeClientWithNullActiveFolder();
+        Message::make(1, 0, $client, "Subject: Test\r\n\r\n", '', []);
+    }
+
+    public function testMakeSucceedsAfterFix(): void
+    {
+        $client = $this->makeClientWithNullActiveFolder();
+
+        $message = Message::make(1, 0, $client, "Subject: Test\r\n\r\n", '', []);
+
+        $this->assertInstanceOf(Message::class, $message);
+        $this->assertIsString($message->getFolderPath());
+        $this->assertNotEmpty($message->getFolderPath());
+    }
+}