Fix task collection attach relation

app/Filament/Clusters/WeeklyOps/Resources/TaskCollections/RelationManagers/TasksRelationManager.php

@@ -19,6 +19,8 @@ class TasksRelationManager extends RelationManager
 {
     protected static string $relationship = 'tasks';
 
+    protected static ?string $inverseRelationship = 'taskCollections';
+
     public function table(Table $table): Table
     {
         return $table

app/Models/Task.php

@@ -44,6 +44,16 @@ class Task extends Model
         return $this->belongsTo(TaskCollection::class, 'collection_id');
     }
 
+    public function taskCollections(): BelongsToMany
+    {
+        return $this->belongsToMany(
+            TaskCollection::class,
+            'task_collection_task',
+            'task_id',
+            'task_collection_id'
+        )->withPivot(['sort_order']);
+    }
+
     public function tenant(): BelongsTo
     {
         return $this->belongsTo(Tenant::class);

tests/Unit/TaskCollectionsRelationTest.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Tests\Unit;
+
+use App\Models\Task;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
+use Tests\TestCase;
+
+class TaskCollectionsRelationTest extends TestCase
+{
+    public function test_task_has_task_collections_relation(): void
+    {
+        $task = new Task;
+        $relation = $task->taskCollections();
+
+        $this->assertInstanceOf(BelongsToMany::class, $relation);
+        $this->assertSame(['sort_order'], $relation->getPivotColumns());
+    }
+}