feat: add ArticleCategory and ArticleCategoryCollection

Author: aspirantzhang

contexts/ArticlePublishing/Domain/Models/Article.php

@@ -15,6 +15,7 @@ private function __construct(
         private string $title,
         private string $body,
         private ArticleStatus $status,
+        private ArticleCategoryCollection $categories,
         private ?CarbonImmutable $created_at = null,
         private ?CarbonImmutable $updated_at = null
     ) {
@@ -25,13 +26,15 @@ public function revise(
         ?string $newTitle,
         ?string $newBody,
         ?ArticleStatus $newStatus,
+        ?ArticleCategoryCollection $categories,
         ?CarbonImmutable $newCreatedAt = null,
     ) {
         $this->title = $newTitle ?? $this->title;
         $this->body = $newBody ?? $this->body;
         if ($newStatus && ! $this->status->equals($newStatus)) {
             $this->transitionStatus($newStatus);
         }
+        $this->categories = $categories ?? $this->categories;
         $this->created_at = $newCreatedAt ?? $this->created_at;
     }
 
@@ -40,11 +43,12 @@ public static function reconstitute(
         string $title,
         string $body,
         ArticleStatus $status,
+        ArticleCategoryCollection $categories,
         ?CarbonImmutable $created_at = null,
         ?CarbonImmutable $updated_at = null,
         array $events = []
     ): self {
-        $article = new self($id, $title, $body, $status, $created_at, $updated_at);
+        $article = new self($id, $title, $body, $status, $categories, $created_at, $updated_at);
         foreach ($events as $event) {
             $article->recordEvent($event);
         }
@@ -56,20 +60,22 @@ public static function createDraft(
         ArticleId $id,
         string $title,
         string $body,
+        ArticleCategoryCollection $categories,
         ?CarbonImmutable $created_at = null,
         ?CarbonImmutable $updated_at = null
     ): self {
-        return new self($id, $title, $body, ArticleStatus::draft(), $created_at, $updated_at);
+        return new self($id, $title, $body, ArticleStatus::draft(), $categories, $created_at, $updated_at);
     }
 
     public static function createPublished(
         ArticleId $id,
         string $title,
         string $body,
+        ArticleCategoryCollection $categories,
         ?CarbonImmutable $created_at = null,
         ?CarbonImmutable $updated_at = null
     ): self {
-        $article = new self($id, $title, $body, ArticleStatus::published(), $created_at, $updated_at);
+        $article = new self($id, $title, $body, ArticleStatus::published(), $categories, $created_at, $updated_at);
         $article->recordEvent(new ArticlePublishedEvent($article->id));
 
         return $article;
@@ -115,6 +121,16 @@ public function getbody(): string
         return $this->body;
     }
 
+    public function getStatus(): ArticleStatus
+    {
+        return $this->status;
+    }
+
+    public function getCategories(): ArticleCategoryCollection
+    {
+        return $this->categories;
+    }
+
     public function getCreatedAt(): CarbonImmutable
     {
         return $this->created_at;
@@ -124,9 +140,4 @@ public function getUpdatedAt(): ?CarbonImmutable
     {
         return $this->updated_at;
     }
-
-    public function getStatus(): ArticleStatus
-    {
-        return $this->status;
-    }
 }

contexts/ArticlePublishing/Domain/Models/ArticleCategory.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Contexts\ArticlePublishing\Domain\Models;
+
+class ArticleCategory
+{
+    private int $id;
+
+    private string $label;
+
+    public function __construct(int $id, string $label)
+    {
+        $this->id = $id;
+        $this->label = $label;
+    }
+
+    public function getId(): int
+    {
+        return $this->id;
+    }
+
+    public function getLabel(): string
+    {
+        return $this->label;
+    }
+
+    public function equals(ArticleCategory $category): bool
+    {
+        return $this->id === $category->getId();
+    }
+}

contexts/ArticlePublishing/Domain/Models/ArticleCategoryCollection.php

@@ -0,0 +1,48 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Contexts\ArticlePublishing\Domain\Models;
+
+use App\Exceptions\BizException;
+use Illuminate\Support\Collection;
+
+class ArticleCategoryCollection
+{
+    private Collection $items;
+
+    public function __construct(array $categories = [])
+    {
+        $this->items = new Collection($categories);
+        $this->validateCategories();
+    }
+
+    private function validateCategories(): void
+    {
+        if ($this->items->isEmpty()) {
+            throw BizException::make('Article categories cannot be empty');
+        }
+
+        $this->items->each(function ($category) {
+            if (! $category instanceof ArticleCategory) {
+                throw BizException::make('Invalid article category')->logContext(['category' => $category]);
+            }
+        });
+    }
+
+    public function getIdsArray(): array
+    {
+        return $this->items->map(fn (ArticleCategory $category) => $category->getId())->toArray();
+    }
+
+    /**
+     * @template T
+     *
+     * @param  callable(ArticleCategory): T  $callback
+     * @return Collection<int, T>
+     */
+    public function map(callable $callback): Collection
+    {
+        return $this->items->map($callback);
+    }
+}

contexts/ArticlePublishing/Tests/Unit/Domain/Models/ArticleCategoryCollectionTest.php

@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Exceptions\BizException;
+use Contexts\ArticlePublishing\Domain\Models\ArticleCategory;
+use Contexts\ArticlePublishing\Domain\Models\ArticleCategoryCollection;
+use Illuminate\Support\Collection;
+use Mockery\MockInterface;
+
+beforeEach(function () {
+    $this->mockCategory = Mockery::mock(ArticleCategory::class);
+    $this->mockCategory->shouldReceive('getId')->andReturn(1);
+});
+
+afterEach(function () {
+    Mockery::close();
+});
+
+it('throws exception when categories array is empty', function () {
+    expect(fn () => new ArticleCategoryCollection([]))
+        ->toThrow(BizException::class, 'Article categories cannot be empty');
+});
+
+it('throws exception when category is not an ArticleCategory instance', function () {
+    expect(fn () => new ArticleCategoryCollection(['invalid']))
+        ->toThrow(BizException::class, 'Invalid article category');
+});
+
+it('creates collection with valid categories', function () {
+    $collection = new ArticleCategoryCollection([$this->mockCategory]);
+
+    expect($collection)
+        ->toBeInstanceOf(ArticleCategoryCollection::class);
+});
+
+it('returns array of category IDs', function () {
+    /** @var MockInterface&ArticleCategory $mockCategory2 */
+    $mockCategory2 = Mockery::mock(ArticleCategory::class);
+    $mockCategory2->shouldReceive('getId')->andReturn(2);
+
+    $collection = new ArticleCategoryCollection([$this->mockCategory, $mockCategory2]);
+
+    expect($collection->getIdsArray())
+        ->toBe([1, 2])
+        ->toBeArray();
+});
+
+it('maps categories with callback', function () {
+    /** @var MockInterface&ArticleCategory $mockCategory2 */
+    $mockCategory2 = Mockery::mock(ArticleCategory::class);
+
+    $collection = new ArticleCategoryCollection([$this->mockCategory, $mockCategory2]);
+
+    $result = $collection->map(fn ($category) => 'mapped_'.spl_object_id($category));
+
+    expect($result)
+        ->toBeInstanceOf(Collection::class)
+        ->toHaveCount(2)
+        ->each->toContain('mapped_');
+});