Enforce minimum unit quantity of 1 in product variant form

packages/admin/src/Filament/Resources/ProductVariantResource.php

@@ -154,7 +154,9 @@ public static function getUnitQtyFormComponent(): TextInput
                 __('lunarpanel::productvariant.form.unit_quantity.label')
             )->helperText(
                 __('lunarpanel::productvariant.form.unit_quantity.helper_text')
-            )->numeric();
+            )
+            ->numeric()
+            ->minValue(1);
     }
 
     public static function getQuantityIncrementFormComponent(): TextInput

packages/core/src/Pricing/DefaultPriceFormatter.php

@@ -14,6 +14,10 @@ public function __construct(
         public ?CurrencyContract $currency = null,
         public int $unitQty = 1
     ) {
+        if ($this->unitQty < 1) {
+            $this->unitQty = 1;
+        }
+
         if (! $this->currency) {
             $this->currency = Currency::getDefault();
         }

tests/admin/Feature/Filament/Resources/ProductVariantResource/Pages/ManageVariantInventoryTest.php

@@ -0,0 +1,33 @@
+<?php
+
+use Livewire\Livewire;
+use Lunar\Admin\Filament\Resources\ProductVariantResource\Pages\ManageVariantInventory;
+use Lunar\Models\Currency;
+use Lunar\Models\Language;
+use Lunar\Models\Product;
+use Lunar\Models\ProductVariant;
+use Lunar\Tests\Admin\Feature\Filament\TestCase;
+
+uses(TestCase::class)
+    ->group('resource.product-variant');
+
+it('rejects a unit quantity below one', function () {
+    Language::factory()->create(['default' => true]);
+    Currency::factory()->create(['default' => true]);
+
+    $product = Product::factory()->create();
+
+    $variant = ProductVariant::factory()->create([
+        'product_id' => $product->id,
+    ]);
+
+    $this->asStaff();
+
+    Livewire::test(
+        ManageVariantInventory::class, [
+            'record' => $variant->getRouteKey(),
+        ])->fillForm([
+            'unit_quantity' => 0,
+        ])->call('save')
+        ->assertHasFormErrors(['unit_quantity' => 'min']);
+});

tests/core/Unit/DataTypes/PriceTest.php

@@ -61,6 +61,18 @@
     expect($dataType->unitFormatted(null, NumberFormatter::CURRENCY, 4))->toEqual('£0.1155');
 });
 
+test('unit qty below one is clamped to one', function () {
+    $currency = Currency::factory()->create([
+        'code' => 'GBP',
+        'decimal_places' => 2,
+    ]);
+
+    $dataType = new Price(1500, $currency, 0);
+
+    expect($dataType->unitDecimal())->toEqual(15.00);
+    expect($dataType->unitFormatted())->toEqual('£15.00');
+});
+
 test('can handle no decimal places', function () {
     $currency = Currency::factory()->create([
         'code' => 'VND',