#Migration & Setup

#Migration helper

Schema::create('categories', function (Blueprint $table): void {
    $table->id();
    $table->string('name');
    $table->unsignedInteger('articles')->default(0);
    $table->nestedSet();

    // SUM / COUNT — non-null, default 0
    $table->nestedSetAggregate('articles_total');
    $table->nestedSetAggregate('articles_count_all');

    // AVG — nullable decimal; null on empty subtree
    $table->nestedSetAggregate('articles_avg', type: 'avg');

    // MIN / MAX — nullable; empty subtree yields NULL
    $table->nestedSetAggregate('articles_min', type: 'min_max');
    $table->nestedSetAggregate('articles_max', type: 'min_max');
});

#Required model conventions

Aggregate columns are derived state. Two rules:

class Category extends Model implements HasNestedSet
{
    use NodeTrait;

    // Aggregate columns must NOT appear in $fillable — the package
    // enforces this and throws AggregateConfigurationException at boot
    // if any aggregate column is found there. They stay readable,
    // castable, hideable; only mass-assignment is rejected.
    protected $fillable = ['name', 'articles'];
    // (Equivalently: list every aggregate column in $guarded if you
    // prefer the deny-list style. The package checks $fillable first
    // and falls back to $guarded.)

    // Declare casts manually — NodeTrait does not register them for you.
    protected $casts = [
        'articles'           => 'integer',
        'articles_total'     => 'integer',
        'articles_count_all' => 'integer',
        'articles_avg'       => 'decimal:4',
        'articles_min'       => 'integer',
        'articles_max'       => 'integer',
    ];
}

#Scope of the mass-assignment guard

The check fires once at registry build (when the model's aggregate definitions are first resolved) via reflection on the $fillable / $guarded properties. That covers the common configurations.

It does not intercept dynamic bypasses applied at runtime:

• Overriding isFillable() or isGuarded() on the model to return values not derivable from the properties.
• Calling Model::unguard() (e.g. in a service provider, seeder, or test setup) — this is a global Eloquent toggle that disables guarding for every model, so an Article::create([...]) after unguard() can write directly to aggregate columns regardless of what the build-time check saw.

In both cases, the next mutation through the package overwrites the clobbered value with the correctly recomputed aggregate, so the only observable effect is that the value you mass-assigned is silently lost. If you rely on Model::unguard() in test code, prefer scoping it with Model::unguarded(fn () => ...) and avoid writing to aggregate columns inside the closure.