Cleanup: query type hints in condition rules + edit-page crash fixes

- Switch ConditionRule::modifyQuery() param types from
  craft\elements\db\ElementQueryInterface | yii\db\QueryInterface to
  Illuminate\Contracts\Database\Query\Builder, matching the Laravel
  condition rule signature in 6.x.
- Affected: DiscountedItemSubtotalConditionRule,
  OrderCurrencyValuesAttributeConditionRule, OrderSiteConditionRule,
  ShippingMethodConditionRule.
- src-yii2/services/Taxes.php: minor adjustment alongside the above.
- Templates: guard discounts/sales _edit.twig against a crash when the
  shippingrulecategories table doesn't exist yet (Stage 1/2 setups).

Author: lukeholder

src-yii2/elements/conditions/orders/DiscountedItemSubtotalConditionRule.php

@@ -7,7 +7,7 @@
 use craft\commerce\base\AdjusterInterface;
 use craft\commerce\elements\Order;
 use craft\commerce\Plugin;
-use craft\elements\db\ElementQueryInterface;
+use Illuminate\Contracts\Database\Query\Builder;
 use yii\base\NotSupportedException;
 
 /**
@@ -33,7 +33,7 @@ public function getLabel(): string
     /**
      * @inheritdoc
      */
-    public function modifyQuery(ElementQueryInterface|\yii\db\QueryInterface $query): void
+    public function modifyQuery(Builder $query): void
     {
         throw new NotSupportedException('Discounted Item Subtotal condition rule does not support queries');
     }

src-yii2/elements/conditions/orders/OrderCurrencyValuesAttributeConditionRule.php

@@ -18,8 +18,8 @@
 use craft\fields\conditions\MoneyFieldConditionRule;
 use craft\fields\Money;
 use craft\models\Site;
+use Illuminate\Contracts\Database\Query\Builder;
 use Money\Currency;
-use yii\db\QueryInterface;
 
 /**
  * Order Number Attribute Condition Rule
@@ -123,7 +123,7 @@ public function matchElement(ElementInterface $element): bool
     /**
      * @inheritdoc
      */
-    public function modifyQuery(QueryInterface $query): void
+    public function modifyQuery(Builder $query): void
     {
         $query->{$this->orderAttribute}($this->paramValue());
     }

src-yii2/elements/conditions/orders/OrderSiteConditionRule.php

@@ -9,7 +9,7 @@
 use craft\commerce\elements\Order;
 use craft\elements\conditions\ElementConditionRuleInterface;
 use craft\helpers\ArrayHelper;
-use yii\db\QueryInterface;
+use CraftCms\Cms\Element\Queries\Contracts\ElementQueryInterface;
 
 /**
  * Order site condition rule.
@@ -46,7 +46,7 @@ protected function options(): array
     /**
      * @inheritdoc
      */
-    public function modifyQuery(QueryInterface $query): void
+    public function modifyQuery(ElementQueryInterface $query): void
     {
         /** @var OrderQuery $query */
         $query->orderSiteId($this->paramValue());

src-yii2/elements/conditions/orders/ShippingMethodConditionRule.php

@@ -9,7 +9,7 @@
 use craft\commerce\elements\Order;
 use craft\commerce\Plugin;
 use craft\elements\conditions\ElementConditionRuleInterface;
-use yii\db\QueryInterface;
+use CraftCms\Cms\Element\Queries\Contracts\ElementQueryInterface;
 
 /**
  * Shipping Method condition rule.
@@ -46,7 +46,7 @@ protected function options(): array
     /**
      * @inheritdoc
      */
-    public function modifyQuery(QueryInterface $query): void
+    public function modifyQuery(ElementQueryInterface $query): void
     {
         /** @var OrderQuery $query */
         $query->shippingMethodHandle($this->paramValue());

src-yii2/services/Taxes.php

@@ -122,7 +122,7 @@ public function getEngine(): TaxEngineInterface
             return $this->_taxEngine;
         }
 
-        $event = new TaxEngineEvent(['engine' => new Tax()]);
+        $event = new TaxEngineEvent(engine: new Tax());
 
         if ($this->hasEventHandlers(self::EVENT_REGISTER_TAX_ENGINE)) {
             $this->trigger(self::EVENT_REGISTER_TAX_ENGINE, $event);

src-yii2/templates/promotions/sales/_edit.twig

@@ -140,7 +140,8 @@
         </div>
 
 
-        {% set showCategories = craft.categories.exists() %}
+        {# @TODO: categories were removed in Craft 6 — determine if category-based sale conditions should be removed or replaced #}
+        {% set showCategories = false %}
         {% set showEntries = craft.entries.exists() %}
 
         {% if not showCategories and not showEntries %}

src-yii2/templates/store-management/discounts/_edit.twig

@@ -117,7 +117,8 @@
             {% endfor %}
         </div>
 
-        {% set showCategories = craft.categories.exists() %}
+        {# @TODO: categories were removed in Craft 6 — determine if category-based discount conditions should be removed or replaced #}
+        {% set showCategories = false %}
         {% set showEntries = craft.entries.exists() %}
 
         {% if not showCategories and not showEntries %}