From f7a761728c60a394d3a1bef97b31d3bf882ba3a5 Mon Sep 17 00:00:00 2001
From: David Badura <david.badura@patchlevel.de>
Date: Sat, 17 Feb 2024 16:54:41 +0100
Subject: [PATCH] add consumer target and replace old projector targets

---
 docs/pages/pipeline.md                        | 35 +++------
 src/Pipeline/Target/ConsumerTarget.php        | 30 ++++++++
 .../Target/ProjectorRepositoryTarget.php      | 34 ---------
 src/Pipeline/Target/ProjectorTarget.php       | 29 -------
 .../Pipeline/Target/ConsumerTargetTest.php    | 33 ++++++++
 .../Target/ProjectorRepositoryTargetTest.php  | 75 -------------------
 .../Pipeline/Target/ProjectorTargetTest.php   | 68 -----------------
 7 files changed, 73 insertions(+), 231 deletions(-)
 create mode 100644 src/Pipeline/Target/ConsumerTarget.php
 delete mode 100644 src/Pipeline/Target/ProjectorRepositoryTarget.php
 delete mode 100644 src/Pipeline/Target/ProjectorTarget.php
 create mode 100644 tests/Unit/Pipeline/Target/ConsumerTargetTest.php
 delete mode 100644 tests/Unit/Pipeline/Target/ProjectorRepositoryTargetTest.php
 delete mode 100644 tests/Unit/Pipeline/Target/ProjectorTargetTest.php

diff --git a/docs/pages/pipeline.md b/docs/pages/pipeline.md
index 96af29bd4..c7a0e0ff3 100644
--- a/docs/pages/pipeline.md
+++ b/docs/pages/pipeline.md
@@ -40,11 +40,11 @@ The pipeline can also be used to create or rebuild a projection:
 ```php
 use Patchlevel\EventSourcing\Pipeline\Pipeline;
 use Patchlevel\EventSourcing\Pipeline\Source\StoreSource;
-use Patchlevel\EventSourcing\Pipeline\Target\ProjectionTarget;
+use Patchlevel\EventSourcing\Pipeline\Target\ConsumerTarget;
 
 $pipeline = new Pipeline(
     new StoreSource($store),
-    new ProjectionTarget($projection)
+    ConsumerTarget::create([$projection]),
 );
 ```
 
@@ -140,38 +140,23 @@ $target = new StoreTarget($store);
     It does not matter whether the previous store was a SingleTable or a MultiTable.
     You can switch back and forth between both store types using the pipeline.
 
-### Projector
+### Consumer
 
-A projector can also be used as a target.
-For example, to set up a new projection or to build a new projection.
+A consumer can also be used as a target.
 
 ```php
-use Patchlevel\EventSourcing\Pipeline\Target\ProjectorTarget;
+use Patchlevel\EventSourcing\Pipeline\Target\ConsumerTarget;
 
-$target = new ProjectorTarget($projector);
+$target = new ConsumerTarget($consumer);
 ```
 
-!!! warning
-
-    This is only recommended for exceptional cases. 
-    By default, projections should only be created using the projectionist.
-
-### Projector Repository
+!!! tip
 
-If you want to build or create all projections from scratch,
-then you can also use the ProjectorRepositoryTarget.
-In this, the individual projectors are iterated and the events are then passed on.
-
-```php
-use Patchlevel\EventSourcing\Pipeline\Target\ProjectorRepositoryTarget;
+    You can also use it to build a new projection from scratch.
 
-$target = new ProjectorRepositoryTarget($projectorRepository);
-```
-
-!!! warning
+!!! note
 
-    This is only recommended for exceptional cases. 
-    By default, projections should only be created using the projectionist.
+    More about the consumer can be found [here](event_bus.md).
 
 ### In Memory
 
diff --git a/src/Pipeline/Target/ConsumerTarget.php b/src/Pipeline/Target/ConsumerTarget.php
new file mode 100644
index 000000000..9b01ddea2
--- /dev/null
+++ b/src/Pipeline/Target/ConsumerTarget.php
@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Pipeline\Target;
+
+use Patchlevel\EventSourcing\EventBus\Consumer;
+use Patchlevel\EventSourcing\EventBus\DefaultConsumer;
+use Patchlevel\EventSourcing\EventBus\Message;
+
+final class ConsumerTarget implements Target
+{
+    public function __construct(
+        private readonly Consumer $consumer,
+    ) {
+    }
+
+    public function save(Message ...$messages): void
+    {
+        foreach ($messages as $message) {
+            $this->consumer->consume($message);
+        }
+    }
+
+    /** @param iterable<object> $listeners */
+    public static function create(iterable $listeners): self
+    {
+        return new self(DefaultConsumer::create($listeners));
+    }
+}
diff --git a/src/Pipeline/Target/ProjectorRepositoryTarget.php b/src/Pipeline/Target/ProjectorRepositoryTarget.php
deleted file mode 100644
index ebc2ed60d..000000000
--- a/src/Pipeline/Target/ProjectorRepositoryTarget.php
+++ /dev/null
@@ -1,34 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Patchlevel\EventSourcing\Pipeline\Target;
-
-use Patchlevel\EventSourcing\EventBus\Message;
-use Patchlevel\EventSourcing\Projection\Projector\MetadataProjectorResolver;
-use Patchlevel\EventSourcing\Projection\Projector\ProjectorRepository;
-use Patchlevel\EventSourcing\Projection\Projector\ProjectorResolver;
-
-final class ProjectorRepositoryTarget implements Target
-{
-    public function __construct(
-        private readonly ProjectorRepository $projectorRepository,
-        private readonly ProjectorResolver $projectorResolver = new MetadataProjectorResolver(),
-    ) {
-    }
-
-    public function save(Message ...$messages): void
-    {
-        $projectors = $this->projectorRepository->projectors();
-
-        foreach ($messages as $message) {
-            foreach ($projectors as $projector) {
-                $subscribeMethods = $this->projectorResolver->resolveSubscribeMethods($projector, $message);
-
-                foreach ($subscribeMethods as $subscribeMethod) {
-                    $subscribeMethod($message);
-                }
-            }
-        }
-    }
-}
diff --git a/src/Pipeline/Target/ProjectorTarget.php b/src/Pipeline/Target/ProjectorTarget.php
deleted file mode 100644
index 49ce59274..000000000
--- a/src/Pipeline/Target/ProjectorTarget.php
+++ /dev/null
@@ -1,29 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Patchlevel\EventSourcing\Pipeline\Target;
-
-use Patchlevel\EventSourcing\EventBus\Message;
-use Patchlevel\EventSourcing\Projection\Projector\MetadataProjectorResolver;
-use Patchlevel\EventSourcing\Projection\Projector\ProjectorResolver;
-
-final class ProjectorTarget implements Target
-{
-    public function __construct(
-        private readonly object $projector,
-        private readonly ProjectorResolver $projectorResolver = new MetadataProjectorResolver(),
-    ) {
-    }
-
-    public function save(Message ...$messages): void
-    {
-        foreach ($messages as $message) {
-            $subscribeMethods = $this->projectorResolver->resolveSubscribeMethods($this->projector, $message);
-
-            foreach ($subscribeMethods as $subscribeMethod) {
-                $subscribeMethod($message);
-            }
-        }
-    }
-}
diff --git a/tests/Unit/Pipeline/Target/ConsumerTargetTest.php b/tests/Unit/Pipeline/Target/ConsumerTargetTest.php
new file mode 100644
index 000000000..4cee25516
--- /dev/null
+++ b/tests/Unit/Pipeline/Target/ConsumerTargetTest.php
@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Patchlevel\EventSourcing\Tests\Unit\Pipeline\Target;
+
+use Patchlevel\EventSourcing\EventBus\Consumer;
+use Patchlevel\EventSourcing\EventBus\Message;
+use Patchlevel\EventSourcing\Pipeline\Target\ConsumerTarget;
+use Patchlevel\EventSourcing\Tests\Unit\Fixture\Email;
+use Patchlevel\EventSourcing\Tests\Unit\Fixture\ProfileCreated;
+use Patchlevel\EventSourcing\Tests\Unit\Fixture\ProfileId;
+use PHPUnit\Framework\TestCase;
+use Prophecy\PhpUnit\ProphecyTrait;
+
+/** @covers \Patchlevel\EventSourcing\Pipeline\Target\ConsumerTarget */
+final class ConsumerTargetTest extends TestCase
+{
+    use ProphecyTrait;
+
+    public function testSave(): void
+    {
+        $message = new Message(
+            new ProfileCreated(ProfileId::fromString('1'), Email::fromString('foo@test.com')),
+        );
+
+        $consumer = $this->prophesize(Consumer::class);
+        $consumer->consume($message)->shouldBeCalledOnce();
+
+        $consumerTarget = new ConsumerTarget($consumer->reveal());
+        $consumerTarget->save($message);
+    }
+}
diff --git a/tests/Unit/Pipeline/Target/ProjectorRepositoryTargetTest.php b/tests/Unit/Pipeline/Target/ProjectorRepositoryTargetTest.php
deleted file mode 100644
index 2adff0b75..000000000
--- a/tests/Unit/Pipeline/Target/ProjectorRepositoryTargetTest.php
+++ /dev/null
@@ -1,75 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Patchlevel\EventSourcing\Tests\Unit\Pipeline\Target;
-
-use Patchlevel\EventSourcing\EventBus\Message;
-use Patchlevel\EventSourcing\Pipeline\Target\ProjectorRepositoryTarget;
-use Patchlevel\EventSourcing\Projection\Projector\ProjectorRepository;
-use Patchlevel\EventSourcing\Projection\Projector\ProjectorResolver;
-use Patchlevel\EventSourcing\Tests\Unit\Fixture\Email;
-use Patchlevel\EventSourcing\Tests\Unit\Fixture\ProfileCreated;
-use Patchlevel\EventSourcing\Tests\Unit\Fixture\ProfileId;
-use PHPUnit\Framework\TestCase;
-use Prophecy\PhpUnit\ProphecyTrait;
-
-/** @covers \Patchlevel\EventSourcing\Pipeline\Target\ProjectorRepositoryTarget */
-final class ProjectorRepositoryTargetTest extends TestCase
-{
-    use ProphecyTrait;
-
-    public function testSave(): void
-    {
-        $message = new Message(
-            new ProfileCreated(ProfileId::fromString('1'), Email::fromString('foo@test.com')),
-        );
-
-        $projector = new class {
-            public Message|null $message = null;
-
-            public function __invoke(Message $message): void
-            {
-                $this->message = $message;
-            }
-        };
-
-        $projectorRepository = $this->prophesize(ProjectorRepository::class);
-        $projectorRepository->projectors()->shouldBeCalledOnce()->willReturn([$projector]);
-
-        $projectorResolver = $this->prophesize(ProjectorResolver::class);
-        $projectorResolver->resolveSubscribeMethods($projector, $message)->shouldBeCalledOnce()->willReturn([$projector(...)]);
-
-        $projectorRepositoryTarget = new ProjectorRepositoryTarget($projectorRepository->reveal(), $projectorResolver->reveal());
-        $projectorRepositoryTarget->save($message);
-
-        self::assertSame($message, $projector->message);
-    }
-
-    public function testSaveNoHit(): void
-    {
-        $message = new Message(
-            new ProfileCreated(ProfileId::fromString('1'), Email::fromString('foo@test.com')),
-        );
-
-        $projector = new class {
-            public Message|null $message = null;
-
-            public function __invoke(Message $message): void
-            {
-                $this->message = $message;
-            }
-        };
-
-        $projectorRepository = $this->prophesize(ProjectorRepository::class);
-        $projectorRepository->projectors()->shouldBeCalledOnce()->willReturn([$projector]);
-
-        $projectorResolver = $this->prophesize(ProjectorResolver::class);
-        $projectorResolver->resolveSubscribeMethods($projector, $message)->shouldBeCalledOnce()->willReturn([]);
-
-        $projectorRepositoryTarget = new ProjectorRepositoryTarget($projectorRepository->reveal(), $projectorResolver->reveal());
-        $projectorRepositoryTarget->save($message);
-
-        self::assertNull($projector->message);
-    }
-}
diff --git a/tests/Unit/Pipeline/Target/ProjectorTargetTest.php b/tests/Unit/Pipeline/Target/ProjectorTargetTest.php
deleted file mode 100644
index 7916b0343..000000000
--- a/tests/Unit/Pipeline/Target/ProjectorTargetTest.php
+++ /dev/null
@@ -1,68 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Patchlevel\EventSourcing\Tests\Unit\Pipeline\Target;
-
-use Patchlevel\EventSourcing\EventBus\Message;
-use Patchlevel\EventSourcing\Pipeline\Target\ProjectorTarget;
-use Patchlevel\EventSourcing\Projection\Projector\ProjectorResolver;
-use Patchlevel\EventSourcing\Tests\Unit\Fixture\Email;
-use Patchlevel\EventSourcing\Tests\Unit\Fixture\ProfileCreated;
-use Patchlevel\EventSourcing\Tests\Unit\Fixture\ProfileId;
-use PHPUnit\Framework\TestCase;
-use Prophecy\PhpUnit\ProphecyTrait;
-
-/** @covers \Patchlevel\EventSourcing\Pipeline\Target\ProjectorTarget */
-final class ProjectorTargetTest extends TestCase
-{
-    use ProphecyTrait;
-
-    public function testSave(): void
-    {
-        $message = new Message(
-            new ProfileCreated(ProfileId::fromString('1'), Email::fromString('foo@test.com')),
-        );
-
-        $projector = new class {
-            public Message|null $message = null;
-
-            public function __invoke(Message $message): void
-            {
-                $this->message = $message;
-            }
-        };
-
-        $projectorResolver = $this->prophesize(ProjectorResolver::class);
-        $projectorResolver->resolveSubscribeMethods($projector, $message)->shouldBeCalledOnce()->willReturn([$projector(...)]);
-
-        $projectorTarget = new ProjectorTarget($projector, $projectorResolver->reveal());
-        $projectorTarget->save($message);
-
-        self::assertSame($message, $projector->message);
-    }
-
-    public function testSaveNoHit(): void
-    {
-        $message = new Message(
-            new ProfileCreated(ProfileId::fromString('1'), Email::fromString('foo@test.com')),
-        );
-
-        $projector = new class {
-            public Message|null $message = null;
-
-            public function __invoke(Message $message): void
-            {
-                $this->message = $message;
-            }
-        };
-
-        $projectorResolver = $this->prophesize(ProjectorResolver::class);
-        $projectorResolver->resolveSubscribeMethods($projector, $message)->shouldBeCalledOnce()->willReturn([]);
-
-        $projectorTarget = new ProjectorTarget($projector, $projectorResolver->reveal());
-        $projectorTarget->save($message);
-
-        self::assertNull($projector->message);
-    }
-}