08. TimelineQuery

.psalm-stubs/symfony-messenger.phpstub

@@ -19,7 +19,7 @@ namespace Symfony\Component\Messenger
         /**
          * @template T
          * @psalm-param object|Envelope $message
-         * @psalm-return T|Envelope<HandledStamp>
+         * @psalm-return T
          */
         private function handle($message) { }
     }

src/App/Controller/GetTimelineController.php

@@ -6,11 +6,15 @@ namespace App\Controller;
 
 use App\Dto\CheepDto;
 use Cheeper\Application\CheepApplicationService;
+use Cheeper\Application\QueryBus;
+use Cheeper\Application\Timeline\TimelineQuery;
+use Cheeper\Application\Timeline\TimelineQueryResponse;
 use Cheeper\DomainModel\Author\AuthorDoesNotExist;
 use Cheeper\DomainModel\Cheep\Cheep;
 use Nelmio\ApiDocBundle\Annotation\Model;
 use OpenApi\Attributes as OA;
 use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Exception\BadRequestException;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\Routing\Annotation\Route;
@@ -22,7 +26,8 @@ final class GetTimelineController extends AbstractController
     private const DEFAULT_TIMELINE_CHUNK_SIZE = 10;
 
     public function __construct(
-        private readonly CheepApplicationService $cheepApplicationService
+        private readonly CheepApplicationService $cheepApplicationService,
+        private readonly QueryBus $queryBus,
     ) {
     }
 
@@ -64,18 +69,30 @@ final class GetTimelineController extends AbstractController
         $this->assertNotEmptyString($id, "Author ID");
         $this->assertValidUuid($id);
 
-        $offset     = $request->query->getInt('offset');
-        $size       = $request->query->getInt('size', self::DEFAULT_TIMELINE_CHUNK_SIZE);
+        $offset = $request->query->getInt('offset');
+
+        if ($offset < 0) {
+            throw new BadRequestException("Offset should be 0 or greater");
+        }
+
+        $size = $request->query->getInt('size', self::DEFAULT_TIMELINE_CHUNK_SIZE);
+
+        if ($size <= 0) {
+            throw new BadRequestException("Size should be greater than 0");
+        }
 
         try {
-            $timeline = $this->cheepApplicationService->timelineFrom($id, $offset, $size);
+            $timeline = $this->queryBus->askFor(
+                new TimelineQuery($id, $offset, $size)
+            );
+            assert($timeline instanceof TimelineQueryResponse);
         } catch (AuthorDoesNotExist) {
             throw $this->createNotFoundException();
         }
 
         $cheeps = array_map(
             static fn (Cheep $c) => CheepDto::assembleFrom($c),
-            $timeline
+            $timeline->timeline
         );
 
         return $this->json($cheeps);

src/Cheeper/Application/CheepApplicationService.php

@@ -5,7 +5,6 @@ declare(strict_types=1);
 namespace Cheeper\Application;
 
 use Cheeper\DomainModel\Author\AuthorDoesNotExist;
-use Cheeper\DomainModel\Author\AuthorId;
 use Cheeper\DomainModel\Author\AuthorRepository;
 use Cheeper\DomainModel\Author\UserName;
 use Cheeper\DomainModel\Cheep\Cheep;
@@ -45,20 +44,6 @@ final class CheepApplicationService
         return $cheep;
     }
 
-    /**
-     * @psalm-param non-empty-string $authorId
-     */
-    public function timelineFrom(string $authorId, int $offset, int $size): array
-    {
-        $author = $this->authorRepository->ofId(AuthorId::fromString($authorId));
-
-        if (null === $author) {
-            throw AuthorDoesNotExist::withAuthorIdOf(AuthorId::fromString($authorId));
-        }
-
-        return $this->cheepRepository->ofFollowingPeopleOf($author, $offset, $size);
-    }
-
     /** @psalm-param non-empty-string $id */
     public function getCheep(string $id): Cheep|null
     {

src/Cheeper/Application/CommandBus.php

@@ -9,4 +9,4 @@ interface CommandBus
 {
     /** @psalm-param T $command */
     public function handle(Command $command): void;
-}
+}

src/Cheeper/Application/CountFollowers/CountFollowersQueryResponse.php

@@ -13,4 +13,4 @@ final class CountFollowersQueryResponse implements QueryResponse
         public readonly int $totalNumberOfFollowers
     ) {
     }
-}
+}

src/Cheeper/Application/QueryBus.php

@@ -15,4 +15,4 @@ interface QueryBus
      * @psalm-return TQueryResponse
      */
     public function askFor(Query $query): QueryResponse;
-}
+}

src/Cheeper/Application/QueryResponse.php

@@ -7,4 +7,4 @@ namespace Cheeper\Application;
 /** @psalm-immutable */
 interface QueryResponse
 {
-}
+}

src/Cheeper/Application/Timeline/TimelineQuery.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Cheeper\Application\Timeline;
+
+use Cheeper\Application\Query;
+
+/** @psalm-immutable */
+final class TimelineQuery implements Query
+{
+    /**
+     * @psalm-param non-empty-string $authorId
+     * @psalm-param positive-int|0 $offste
+     * @psalm-param positive-int $size
+     */
+    public function __construct(
+        public readonly string $authorId,
+        public readonly int $offset,
+        public readonly int $size,
+    ) {
+    }
+}

src/Cheeper/Application/Timeline/TimelineQueryHandler.php

@@ -0,0 +1,35 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Cheeper\Application\Timeline;
+
+use Cheeper\DomainModel\Author\AuthorDoesNotExist;
+use Cheeper\DomainModel\Author\AuthorId;
+use Cheeper\DomainModel\Author\AuthorRepository;
+use Cheeper\DomainModel\Cheep\CheepRepository;
+use Symfony\Component\Messenger\Attribute\AsMessageHandler;
+
+#[AsMessageHandler]
+final class TimelineQueryHandler
+{
+    public function __construct(
+        private readonly AuthorRepository $authorRepository,
+        private readonly CheepRepository  $cheepRepository,
+    ) {
+    }
+
+    public function __invoke(TimelineQuery $query): TimelineQueryResponse
+    {
+        $authorId = AuthorId::fromString($query->authorId);
+        $author = $this->authorRepository->ofId($authorId);
+
+        if (null === $author) {
+            throw AuthorDoesNotExist::withAuthorIdOf($authorId);
+        }
+
+        return new TimelineQueryResponse(
+            $this->cheepRepository->ofFollowingPeopleOf($author, $query->offset, $query->size)
+        );
+    }
+}

src/Cheeper/Application/Timeline/TimelineQueryResponse.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Cheeper\Application\Timeline;
+
+use Cheeper\Application\QueryResponse;
+use Cheeper\DomainModel\Cheep\Cheep;
+
+/** @psalm-immutable */
+final class TimelineQueryResponse implements QueryResponse
+{
+    /**
+     * @psalm-param list<Cheep> $timeline
+     * @param Cheep[] $timeline
+     */
+    public function __construct(
+        public readonly array $timeline
+    ) {
+    }
+}

src/Cheeper/Infrastructure/Application/SymfonyMessengerCommandBus.php

@@ -19,4 +19,4 @@ final class SymfonyMessengerCommandBus implements CommandBus
     {
         $this->commandBus->dispatch($command);
     }
-}
+}

src/Cheeper/Infrastructure/Application/SymfonyMessengerQueryBus.php

@@ -7,11 +7,8 @@ namespace Cheeper\Infrastructure\Application;
 use Cheeper\Application\Query;
 use Cheeper\Application\QueryBus;
 use Cheeper\Application\QueryResponse;
-use Symfony\Component\Messenger\Envelope;
-use Symfony\Component\Messenger\Exception\LogicException;
 use Symfony\Component\Messenger\HandleTrait;
 use Symfony\Component\Messenger\MessageBusInterface;
-use Symfony\Component\Messenger\Stamp\HandledStamp;
 
 final class SymfonyMessengerQueryBus implements QueryBus
 {
@@ -30,4 +27,4 @@ final class SymfonyMessengerQueryBus implements QueryBus
 
         return $result;
     }
-}
+}

tests/Cheeper/Tests/Application/CheepApplicationServiceTest.php

@@ -18,15 +18,13 @@ use Psl\Iter;
 
 final class CheepApplicationServiceTest extends TestCase
 {
-    private CheepRepository $cheepRepository;
     private AuthorRepository $authorRepository;
     private CheepApplicationService $cheepService;
 
     public function setUp(): void
     {
-        $this->cheepRepository = new InMemoryCheepRepository();
         $this->authorRepository = new InMemoryAuthorRepository();
-        $this->cheepService = new CheepApplicationService($this->authorRepository, $this->cheepRepository);
+        $this->cheepService = new CheepApplicationService($this->authorRepository, new InMemoryCheepRepository());
     }
 
     /** @test */
@@ -53,33 +51,4 @@ final class CheepApplicationServiceTest extends TestCase
         $this->assertNotNull($cheep->authorId());
         $this->assertEquals('message', $cheep->cheepMessage()->message);
     }
-
-    /** @test */
-    public function givenATimelineRequestWhenTheAuthorDoesNotExistThenAnExceptionShouldBeThrown(): void
-    {
-        $this->expectException(AuthorDoesNotExist::class);
-
-        $this->cheepService->timelineFrom(AuthorTestDataBuilder::anAuthorIdentity()->id, 0, 1);
-    }
-
-    /** @test */
-    public function givenATimelineRequestWhenExecutionGoesWellThenAListOfCheepsShouldBeReturned(): void
-    {
-        $author = AuthorTestDataBuilder::anAuthor()->build();
-
-        $this->authorRepository->add($author);
-
-        $cheeps = [
-            CheepTestDataBuilder::aCheep()->withAMessage("test1")->build(),
-            CheepTestDataBuilder::aCheep()->withAMessage("test2")->build(),
-            CheepTestDataBuilder::aCheep()->withAMessage("test3")->build(),
-        ];
-
-        Iter\apply($cheeps, fn(Cheep $c) => $this->cheepRepository->add($c));
-
-        $this->assertCount(
-            count($cheeps),
-            $this->cheepService->timelineFrom($author->authorId()->id, 0, 10)
-        );
-    }
 }

tests/Cheeper/Tests/Application/TimelineQueryHandlerTest.php

@@ -0,0 +1,78 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Cheeper\Tests\Application;
+
+use Cheeper\Application\CheepApplicationService;
+use Cheeper\Application\Timeline\TimelineQuery;
+use Cheeper\Application\Timeline\TimelineQueryHandler;
+use Cheeper\Application\Timeline\TimelineQueryResponse;
+use Cheeper\DomainModel\Author\AuthorDoesNotExist;
+use Cheeper\DomainModel\Author\AuthorRepository;
+use Cheeper\DomainModel\Cheep\Cheep;
+use Cheeper\DomainModel\Cheep\CheepRepository;
+use Cheeper\Infrastructure\Persistence\InMemoryAuthorRepository;
+use Cheeper\Infrastructure\Persistence\InMemoryCheepRepository;
+use Cheeper\Tests\DomainModel\Author\AuthorTestDataBuilder;
+use Cheeper\Tests\DomainModel\Cheep\CheepTestDataBuilder;
+use PHPUnit\Framework\TestCase;
+use Psl\Iter;
+
+final class TimelineQueryHandlerTest extends TestCase
+{
+    private CheepRepository $cheepRepository;
+    private AuthorRepository $authorRepository;
+    private CheepApplicationService $cheepService;
+    private TimelineQueryHandler $timelineQueryHandler;
+
+    public function setUp(): void
+    {
+        $this->cheepRepository = new InMemoryCheepRepository();
+        $this->authorRepository = new InMemoryAuthorRepository();
+        $this->cheepService = new CheepApplicationService($this->authorRepository, $this->cheepRepository);
+        $this->timelineQueryHandler = new TimelineQueryHandler($this->authorRepository, $this->cheepRepository);
+    }
+
+    /** @test */
+    public function givenATimelineRequestWhenTheAuthorDoesNotExistThenAnExceptionShouldBeThrown(): void
+    {
+        $this->expectException(AuthorDoesNotExist::class);
+
+        $this->timelineFrom(AuthorTestDataBuilder::anAuthorIdentity()->id, 0, 1);
+    }
+
+    /** @test */
+    public function givenATimelineRequestWhenExecutionGoesWellThenAListOfCheepsShouldBeReturned(): void
+    {
+        $author = AuthorTestDataBuilder::anAuthor()->build();
+
+        $this->authorRepository->add($author);
+
+        $cheeps = [
+            CheepTestDataBuilder::aCheep()->withAMessage("test1")->build(),
+            CheepTestDataBuilder::aCheep()->withAMessage("test2")->build(),
+            CheepTestDataBuilder::aCheep()->withAMessage("test3")->build(),
+        ];
+
+        Iter\apply($cheeps, fn(Cheep $c) => $this->cheepRepository->add($c));
+
+        $this->assertCount(
+            count($cheeps),
+            $this->timelineFrom($author->authorId()->id, 0, 10)->timeline
+        );
+    }
+
+    /**
+     * @param non-empty-string $authorId
+     * @param positive-int|0 $offset
+     * @param positive-int $size
+     * @return TimelineQueryResponse
+     */
+    private function timelineFrom(string $authorId, int $offset, int $size): TimelineQueryResponse
+    {
+        return ($this->timelineQueryHandler)(
+            new TimelineQuery($authorId, $offset, $size)
+        );
+    }
+}