can reset subscription from subscriber entity

src/Entities/Subscriber.php

@@ -368,6 +368,32 @@ class Subscriber extends Entity
         }
     }
 
+    /**
+     * @param string      $listId
+     * @param string|null $tagId
+     * @param array|null  $fields
+     * @param string|null $smsNumber
+     *
+     * @return void
+     * @throws CommunicationException
+     */
+    public function resubscribe(
+        string $listId,
+        ?string $tagId = null,
+        ?array $fields = null,
+        ?string $smsNumber = null
+    ): void {
+        if (!$this->isSubscribed()) {
+            $this->endpoint->subscribe(
+                $this->getEmailAddress(),
+                $listId,
+                $tagId,
+                $fields,
+                $smsNumber
+            );
+        }
+    }
+
     // missing getters (return is timestamp list)
 
     // smart_links  SmartLinks

tests/unit/Entities/SubscriberTest.php

@@ -978,4 +978,44 @@ class SubscriberTest extends TestCase
         yield ['getStartedCampaignTime', 'getStartedCampaigns'];
         yield ['getFinishedCampaignTime', 'getFinishedCampaigns'];
     }
+
+    /**
+     * @test
+     * @throws ReflectionException
+     * @covers \D3\KlicktippPhpClient\Entities\Subscriber::resubscribe
+     * @dataProvider  resubscribeDataProvider
+     */
+    public function testReSubscribe(
+        bool $endpointSet,
+        InvokedCount $subscribeExpections,
+        bool $isSubscribed
+    ): void
+    {
+        $endpointMock = $this->getMockBuilder(SubscriberEndpoint::class)
+            ->disableOriginalConstructor()
+            ->onlyMethods(['subscribe'])
+            ->getMock();
+        $endpointMock->expects($subscribeExpections)->method('subscribe');
+
+        $sut = $this->getMockBuilder(Subscriber::class)
+            ->setConstructorArgs([[], $endpointSet ? $endpointMock : null])
+            ->onlyMethods(['isSubscribed', 'getEmailAddress'])
+            ->getMock();
+        $sut->method('isSubscribed')->willReturn($isSubscribed);
+        $sut->method('getEmailAddress')->willReturn('mail@mydomain.tld');
+
+        $this->callMethod(
+            $sut,
+            'resubscribe',
+            ['listId', 'tagid']
+        );
+    }
+
+    public static function resubscribeDataProvider(): Generator
+    {
+        yield 'already subscribed, has endpoint' => [true, self::never(), true];
+        yield 'unsubscribed, has endpoint' => [true, self::once(), false];
+        yield 'already subscribed, no endpoint' => [false, self::never(), true];
+        yield 'unsubscribed, no endpoint' => [false, self::never(), false];
+    }
 }