Feat(hashtags): Add hashtag storage and relation syncing

app/EventActions/UpdateQuestionHashtags.php

@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\EventActions;
+
+use App\Models\Hashtag;
+use App\Models\Question;
+use Illuminate\Support\Collection;
+use Illuminate\Support\Str;
+
+final readonly class UpdateQuestionHashtags
+{
+    /**
+     * Create a new class instance.
+     */
+    public function __construct(
+        public Question $question,
+    ) {
+        //
+    }
+
+    /**
+     * @return array{attached: array<int, int>, detached: array<int, int>, updated: array<int, int>}
+     */
+    public function handle(): array
+    {
+        $parsedHashtags = $this->parsedHashtagNames();
+
+        $existingHashtags = Hashtag::query()->whereIn('name', $parsedHashtags->all())->get();
+
+        $newHashtags = $parsedHashtags->diff($existingHashtags->pluck('name'))
+            ->map(fn (string $name): Hashtag => Hashtag::query()->create(['name' => $name]));
+
+        return $this->question->hashtags()->sync($existingHashtags->merge($newHashtags));
+    }
+
+    /**
+     * Get the unique hashtag names found in the question.
+     *
+     * @return Collection<int, string>
+     */
+    private function parsedHashtagNames(): Collection
+    {
+        $matches = [];
+
+        preg_match_all(
+            '/(<(a|code|pre)\s+[^>]*>.*?<\/\2>)|(?<!&)#([a-z0-9]+)/is',
+            "{$this->question->answer} {$this->question->content}",
+            $matches,
+        );
+
+        return collect($matches[3] ?? [])
+            ->filter()
+            ->unique()
+            ->values()
+            ->map(fn (string $hashtag): string => Str::limit($hashtag, 50, ''));
+    }
+}

app/Models/Hashtag.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models;
+
+use Carbon\Carbon;
+use Database\Factories\HashtagFactory;
+use Illuminate\Database\Eloquent\Collection;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
+
+/**
+ * @property int $id
+ * @property string $name
+ * @property Carbon $created_at
+ * @property Carbon $updated_at
+ * @property-read Collection<int, Question> $questions
+ */
+final class Hashtag extends Model
+{
+    /** @use HasFactory<HashtagFactory> */
+    use HasFactory;
+
+    /**
+     * The attributes that should be cast.
+     *
+     * @return array<string, string>
+     */
+    public function casts(): array
+    {
+        return [
+            'created_at' => 'datetime',
+            'updated_at' => 'datetime',
+        ];
+    }
+
+    /**
+     * @return BelongsToMany<Question>
+     */
+    public function questions(): BelongsToMany
+    {
+        return $this->belongsToMany(Question::class);
+    }
+}

app/Models/Question.php

@@ -14,6 +14,7 @@
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Support\Carbon;
 
@@ -39,6 +40,7 @@
  * @property-read Collection<int, User> $mentions
  * @property-read Question|null $parent
  * @property-read Collection<int, Question> $children
+ * @property-read Collection<int, Hashtag> $hashtags
  */
 #[ObservedBy(QuestionObserver::class)]
 final class Question extends Model implements Viewable
@@ -186,4 +188,12 @@ public function children(): HasMany
             ->where('is_ignored', false)
             ->where('is_reported', false);
     }
+
+    /**
+     * @return BelongsToMany<Hashtag>
+     */
+    public function hashtags(): BelongsToMany
+    {
+        return $this->belongsToMany(Hashtag::class);
+    }
 }

app/Observers/QuestionObserver.php

@@ -4,6 +4,7 @@
 
 namespace App\Observers;
 
+use App\EventActions\UpdateQuestionHashtags;
 use App\Models\Question;
 use App\Models\User;
 use App\Notifications\QuestionAnswered;
@@ -30,6 +31,8 @@ public function created(Question $question): void
             $question->loadMissing('to');
             $question->to->notify(new QuestionCreated($question));
         }
+
+        (new UpdateQuestionHashtags($question))->handle();
     }
 
     /**
@@ -47,6 +50,10 @@ public function updated(Question $question): void
             $question->to->notifications()->whereJsonContains('data->question_id', $question->id)->delete();
         }
 
+        if ($question->isDirty(['answer', 'content'])) {
+            (new UpdateQuestionHashtags($question))->handle();
+        }
+
         if ($question->isDirty('answer') === false) {
             return;
         }
@@ -72,5 +79,7 @@ public function deleted(Question $question): void
         });
 
         $question->children->each->delete();
+
+        $question->hashtags()->detach();
     }
 }

app/Services/ParsableContentProviders/HashtagProviderParsable.php

@@ -5,6 +5,7 @@
 namespace App\Services\ParsableContentProviders;
 
 use App\Contracts\Services\ParsableContentProvider;
+use Illuminate\Support\Str;
 
 final readonly class HashtagProviderParsable implements ParsableContentProvider
 {
@@ -14,10 +15,13 @@
     public function parse(string $content): string
     {
         return (string) preg_replace_callback(
-            '/(<(a|code|pre)\s+[^>]*>.*?<\/\2>)|(?<!&)#([a-z0-9_]+)/is',
+            '/(<(a|code|pre)\s+[^>]*>.*?<\/\2>)|(?<!&)#([a-z0-9]+)/is',
             fn (array $matches): string => $matches[1] !== ''
                 ? $matches[1]
-                : '<span class="text-blue-500">#'.$matches[3].'</span>',
+                : sprintf(
+                    '<span class="text-blue-500">#%s</span>',
+                    Str::limit($matches[3], 200, '')
+                ),
             $content
         );
     }

database/factories/HashtagFactory.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Database\Factories;
+
+use App\Models\Hashtag;
+use Database\Factories\Concerns\RefreshOnCreate;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+/**
+ * @extends Factory<Hashtag>
+ */
+final class HashtagFactory extends Factory
+{
+    use RefreshOnCreate;
+
+    /**
+     * Define the model's default state.
+     *
+     * @return array<string, mixed>
+     */
+    public function definition(): array
+    {
+        return [
+            'name' => $this->faker->word(),
+        ];
+    }
+}

database/migrations/2024_08_07_203106_create_hashtags_table.php

@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Models\Hashtag;
+use App\Models\Question;
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('hashtags', function (Blueprint $table): void {
+            $table->id();
+            $table->string('name')->unique();
+            $table->timestamps();
+
+            $table->rawIndex('name collate nocase', 'name_collate_nocase');
+        });
+
+        Schema::create('hashtag_question', function (Blueprint $table): void {
+            $table->id();
+            $table->foreignIdFor(Hashtag::class)->constrained()->cascadeOnDelete();
+            $table->foreignIdFor(Question::class)->constrained()->cascadeOnDelete();
+
+            $table->unique(['hashtag_id', 'question_id']);
+        });
+    }
+};

tests/Arch/ModelsTest.php

@@ -11,6 +11,7 @@
     ->toOnlyBeUsedIn([
         'App\Concerns',
         'App\Console',
+        'App\EventActions',
         'App\Filament',
         'App\Http',
         'App\Jobs',
@@ -28,7 +29,7 @@
     ])->ignoring('App\Models\Concerns');
 
 arch('ensure factories', function () {
-    expect($models = getModels())->toHaveCount(5);
+    expect($models = getModels())->toHaveCount(6);
 
     foreach ($models as $model) {
         /* @var \Illuminate\Database\Eloquent\Factories\HasFactory $model */
@@ -38,7 +39,7 @@
 });
 
 arch('ensure datetime casts', function () {
-    expect($models = getModels())->toHaveCount(5);
+    expect($models = getModels())->toHaveCount(6);
 
     foreach ($models as $model) {
         /* @var \Illuminate\Database\Eloquent\Factories\HasFactory $model */

tests/Unit/EventActions/UpdateQuestionHashtagsTest.php

@@ -0,0 +1,75 @@
+<?php
+
+declare(strict_types=1);
+
+use App\EventActions\UpdateQuestionHashtags;
+use App\Models\Hashtag;
+use App\Models\Question;
+
+it('attaches the newly parsed hashtags', function () {
+    $question = Question::factory()->create();
+
+    $question->answer = '#hashtag1 #hashtag2';
+
+    $synced = (new UpdateQuestionHashtags($question))->handle();
+
+    $hashtag1 = Hashtag::query()->firstWhere('name', 'hashtag1');
+    $hashtag2 = Hashtag::query()->firstWhere('name', 'hashtag2');
+
+    expect($synced)->toBe([
+        'attached' => [
+            $hashtag1->id,
+            $hashtag2->id,
+        ],
+        'detached' => [],
+        'updated' => [],
+    ])
+        ->and($question->hashtags->pluck('name')->all())->toBe(['hashtag1', 'hashtag2']);
+});
+
+it('detaches hashtags no longer found in the question', function () {
+    $question = Question::factory()->create([
+        'answer' => '#hashtag1 #hashtag2',
+    ]);
+
+    expect($question->hashtags->pluck('name')->all())->toBe(['hashtag1', 'hashtag2']);
+
+    $question->answer = '#hashtag3';
+
+    $synced = (new UpdateQuestionHashtags($question))->handle();
+
+    $hashtag1 = Hashtag::query()->firstWhere('name', 'hashtag1');
+    $hashtag2 = Hashtag::query()->firstWhere('name', 'hashtag2');
+    $hashtag3 = Hashtag::query()->firstWhere('name', 'hashtag3');
+
+    expect($synced)->toBe([
+        'attached' => [
+            $hashtag3->id,
+        ],
+        'detached' => [
+            $hashtag1->id,
+            $hashtag2->id,
+        ],
+        'updated' => [],
+    ])
+        ->and($question->refresh()->hashtags->pluck('name')->all())->toBe(['hashtag3']);
+});
+
+it('will not parse hashtags within code and links', function () {
+    $question = Question::factory()->create();
+
+    $question->answer = <<<'ANSWER'
+            ```php
+            // some code with a #hashtag here.
+            $url = https://example.com/route#segment
+            ```
+
+            Check out this link with a segment: https://example.com/route#segment
+
+            But the #cool hashtag should be synced!
+            ANSWER;
+
+    (new UpdateQuestionHashtags($question))->handle();
+
+    expect($question->hashtags->pluck('name')->all())->toBe(['cool']);
+});

tests/Unit/Models/HashtagTest.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Models\Hashtag;
+use App\Models\Question;
+
+test('to array', function () {
+    $question = Hashtag::factory()->create();
+
+    expect(array_keys($question->toArray()))->toBe([
+        'id',
+        'name',
+        'created_at',
+        'updated_at',
+    ]);
+});
+
+test('relations', function () {
+    $hashtag = Hashtag::factory()
+        ->hasQuestions(1)
+        ->create();
+
+    expect($hashtag->questions)->each->toBeInstanceOf(Question::class);
+});