Handle moving messages when server only has UIDPLUS capability

src/Folder.php

@@ -13,11 +13,6 @@
 
 class Folder implements Arrayable, FolderInterface, JsonSerializable
 {
-    /**
-     * The folder's cached capabilities.
-     */
-    protected array $capabilities;
-
     /**
      * Constructor.
      */
@@ -96,8 +91,8 @@ public function messages(): MessageQuery
      */
     public function idle(callable $callback, ?callable $query = null, int $timeout = 300): void
     {
-        if (! $this->hasCapability('IDLE')) {
-            throw new ImapCapabilityException('IMAP server does not support IDLE');
+        if (! in_array('IDLE', $this->mailbox->capabilities())) {
+            throw new ImapCapabilityException('Unable to IDLE. IMAP server does not support IDLE capability.');
         }
 
         // The message query to use when fetching messages.
@@ -198,22 +193,6 @@ public function delete(): void
         $this->mailbox->connection()->delete($this->path);
     }
 
-    /**
-     * Determine if the mailbox has the given capability.
-     */
-    protected function hasCapability(string $capability): bool
-    {
-        return in_array($capability, $this->capabilities());
-    }
-
-    /**
-     * Get and in-memory cache the mailboxes's capabilities.
-     */
-    protected function capabilities(): array
-    {
-        return $this->capabilities ??= $this->mailbox->capabilities();
-    }
-
     /**
      * Get the array representation of the folder.
      */

src/Mailbox.php

@@ -32,6 +32,13 @@ class Mailbox implements MailboxInterface
         ],
     ];
 
+    /**
+     * The cached mailbox capabilities.
+     *
+     * @see https://datatracker.ietf.org/doc/html/rfc9051#section-6.1.1
+     */
+    protected ?array $capabilities = null;
+
     /**
      * The currently selected folder.
      */
@@ -194,9 +201,9 @@ public function folders(): FolderRepositoryInterface
      */
     public function capabilities(): array
     {
-        return array_map(
+        return $this->capabilities ??= array_map(
             fn (Atom $token) => $token->value,
-            $this->connection()->capability()->tokensAfter(1)
+            $this->connection()->capability()->tokensAfter(2)
         );
     }
 

src/Message.php

@@ -4,6 +4,7 @@
 
 use BackedEnum;
 use DirectoryTree\ImapEngine\Enums\ImapFlag;
+use DirectoryTree\ImapEngine\Exceptions\ImapCapabilityException;
 use DirectoryTree\ImapEngine\Support\Str;
 use Illuminate\Contracts\Support\Arrayable;
 use JsonSerializable;
@@ -292,12 +293,31 @@ public function copy(string $folder): void
      */
     public function move(string $folder, bool $expunge = false): void
     {
-        $this->folder->mailbox()
-            ->connection()
-            ->move($folder, $this->uid);
+        $mailbox = $this->folder->mailbox();
 
-        if ($expunge) {
-            $this->folder->expunge();
+        $capabilities = $mailbox->capabilities();
+
+        switch (true) {
+            case in_array('MOVE', $capabilities):
+                $mailbox->connection()->move($folder, $this->uid);
+
+                if ($expunge) {
+                    $this->folder->expunge();
+                }
+
+                return;
+
+            case in_array('UIDPLUS', $capabilities):
+                $this->copy($folder);
+
+                $this->delete($expunge);
+
+                return;
+
+            default:
+                throw new ImapCapabilityException(
+                    'Unable to move message. IMAP server does not support MOVE or UIDPLUS capabilities'
+                );
         }
     }
 

tests/Integration/MailboxTest.php

@@ -18,7 +18,6 @@
     $mailbox = mailbox();
 
     expect($mailbox->capabilities())->toBe([
-        'CAPABILITY',
         'IMAP4rev1',
         'LITERAL+',
         'UIDPLUS',

tests/Unit/MailboxTest.php

@@ -119,3 +119,23 @@
     expect($folder->path())->toBe('INBOX');
     expect($folder->flags())->toBe(['\\HasNoChildren']);
 });
+
+test('capabilities', function () {
+    $mailbox = Mailbox::make([
+        'username' => 'foo',
+        'password' => 'bar',
+    ]);
+
+    $mailbox->connect(ImapConnection::fake([
+        '* OK Welcome to IMAP',
+        'TAG1 OK Logged in',
+        '* CAPABILITY IMAP4rev1 STARTTLS AUTH=PLAIN',
+        'TAG2 OK CAPABILITY completed',
+    ]));
+
+    expect($mailbox->capabilities())->toBe([
+        'IMAP4rev1',
+        'STARTTLS',
+        'AUTH=PLAIN',
+    ]);
+});

tests/Unit/MessageTest.php

@@ -0,0 +1,105 @@
+<?php
+
+use DirectoryTree\ImapEngine\Connection\ImapConnection;
+use DirectoryTree\ImapEngine\Enums\ImapFlag;
+use DirectoryTree\ImapEngine\Exceptions\ImapCapabilityException;
+use DirectoryTree\ImapEngine\Folder;
+use DirectoryTree\ImapEngine\Mailbox;
+use DirectoryTree\ImapEngine\Message;
+
+test('it moves message using MOVE when capable', function () {
+    $mailbox = Mailbox::make([
+        'username' => 'foo',
+        'password' => 'bar',
+    ]);
+
+    $mailbox->connect(ImapConnection::fake([
+        '* OK Welcome to IMAP',
+        'TAG1 OK Logged in',
+        '* CAPABILITY IMAP4rev1 STARTTLS MOVE AUTH=PLAIN',
+        'TAG2 OK CAPABILITY completed',
+        'TAG3 OK MOVE completed',
+    ]));
+
+    $folder = new Folder($mailbox, 'INBOX', [], '/');
+
+    $message = new Message($folder, 1, [], 'header', 'body');
+
+    $message->move('INBOX.Sent');
+})->throwsNoExceptions();
+
+test('it copies and then deletes message using UIDPLUS when incapable of MOVE', function () {
+    $mailbox = Mailbox::make([
+        'username' => 'foo',
+        'password' => 'bar',
+    ]);
+
+    $mailbox->connect(ImapConnection::fake([
+        '* OK Welcome to IMAP',
+        'TAG1 OK Logged in',
+        '* CAPABILITY IMAP4rev1 STARTTLS UIDPLUS AUTH=PLAIN',
+        'TAG2 OK CAPABILITY completed',
+        'TAG3 OK UID MOVE completed',
+        'TAG4 OK COPY completed',
+    ]));
+
+    $folder = new Folder($mailbox, 'INBOX', [], '/');
+
+    $message = new Message($folder, 1, [], 'header', 'body');
+
+    $message->move('INBOX.Sent');
+})->throwsNoExceptions();
+
+test('it throws exception when server does not support MOVE or UIDPLUS capabilities', function () {
+    $mailbox = Mailbox::make([
+        'username' => 'foo',
+        'password' => 'bar',
+    ]);
+
+    $mailbox->connect(ImapConnection::fake([
+        '* OK Welcome to IMAP',
+        'TAG1 OK Logged in',
+        '* CAPABILITY IMAP4rev1 STARTTLS AUTH=PLAIN',
+        'TAG2 OK CAPABILITY completed',
+    ]));
+
+    $folder = new Folder($mailbox, 'INBOX', [], '/');
+
+    $message = new Message($folder, 1, [], 'header', 'body');
+
+    $message->move('INBOX.Sent');
+})->throws(ImapCapabilityException::class);
+
+test('it can mark and unmark a message as flagged', function () {
+    $mailbox = Mailbox::make([
+        'username' => 'foo',
+        'password' => 'bar',
+    ]);
+
+    $mailbox->connect(ImapConnection::fake([
+        '* OK Welcome to IMAP',
+        'TAG1 OK Logged in',
+        '* CAPABILITY IMAP4rev1 STARTTLS AUTH=PLAIN',
+        'TAG2 OK CAPABILITY completed',
+        'TAG3 OK STORE completed',
+    ]));
+
+    $folder = new Folder($mailbox, 'INBOX', [], '/');
+
+    $message = new Message($folder, 1, [], 'header', 'body');
+
+    expect($message->isFlagged())->toBeFalse();
+    expect($message->flags())->not->toContain('\\Flagged');
+
+    $message->markFlagged();
+
+    expect($message->isFlagged())->toBeTrue();
+    expect($message->flags())->toContain('\\Flagged');
+    expect($message->hasFlag(ImapFlag::Flagged))->toBeTrue();
+
+    $message->unmarkFlagged();
+
+    expect($message->isFlagged())->toBeFalse();
+    expect($message->flags())->not->toContain('\\Flagged');
+    expect($message->hasFlag(ImapFlag::Flagged))->toBeFalse();
+});