Improve, add tests and fix issues

src/AbstractActiveRecord.php

@@ -38,6 +38,8 @@
  * ActiveRecord is the base class for classes representing relational data in terms of objects.
  *
  * See {@see ActiveRecord} for a concrete implementation.
+ *
+ * @psalm-import-type ARClass from ActiveQueryInterface
  */
 abstract class AbstractActiveRecord implements ActiveRecordInterface
 {
@@ -260,16 +262,17 @@ public function hasAttribute(string $name): bool
      *
      * Call methods declared in {@see ActiveQuery} to further customize the relation.
      *
-     * @param string $class The class name of the related record
+     * @param string|ActiveRecordInterface|Closure $class The class name of the related record, or an instance of the
+     * related record, or a Closure to create an {@see ActiveRecordInterface} object.
      * @param array $link The primary-foreign key constraint. The keys of the array refer to the attributes of the
      * record associated with the `$class` model, while the values of the array refer to the corresponding attributes in
      * **this** AR class.
      *
      * @return ActiveQueryInterface The relational query object.
      *
-     * @psalm-param class-string<ActiveRecordInterface> $class
+     * @psalm-param ARClass $class
      */
-    public function hasMany(string $class, array $link): ActiveQueryInterface
+    public function hasMany(string|ActiveRecordInterface|Closure $class, array $link): ActiveQueryInterface
     {
         return $this->createRelationQuery($class, $link, true);
     }
@@ -298,16 +301,17 @@ public function hasMany(string $class, array $link): ActiveQueryInterface
      *
      * Call methods declared in {@see ActiveQuery} to further customize the relation.
      *
-     * @param string $class The class name of the related record.
+     * @param string|ActiveRecordInterface|Closure $class The class name of the related record, or an instance of the
+     *  related record, or a Closure to create an {@see ActiveRecordInterface} object.
      * @param array $link The primary-foreign key constraint. The keys of the array refer to the attributes of the
      * record associated with the `$class` model, while the values of the array refer to the corresponding attributes in
      * **this** AR class.
      *
      * @return ActiveQueryInterface The relational query object.
      *
-     * @psalm-param class-string<ActiveRecordInterface> $class
+     * @psalm-param ARClass $class
      */
-    public function hasOne(string $class, array $link): ActiveQueryInterface
+    public function hasOne(string|ActiveRecordInterface|Closure $class, array $link): ActiveQueryInterface
     {
         return $this->createRelationQuery($class, $link, false);
     }
@@ -318,9 +322,12 @@ public function insert(array $attributes = null): bool
     }
 
     /**
-     * @psalm-param class-string<ActiveRecordInterface> $arClass
+     * @param string|ActiveRecordInterface|Closure $arClass The class name of the related record, or an instance of the
+     * related record, or a Closure to create an {@see ActiveRecordInterface} object.
+     *
+     * @psalm-param ARClass $arClass
      */
-    public function instantiateQuery(string $arClass): ActiveQueryInterface
+    public function instantiateQuery(string|ActiveRecordInterface|Closure $arClass): ActiveQueryInterface
     {
         return new ActiveQuery($arClass, $this->db);
     }
@@ -1070,18 +1077,18 @@ protected function setRelationDependencies(
     /**
      * Creates a query instance for `has-one` or `has-many` relation.
      *
-     * @param string $arClass The class name of the related record.
+     * @param string|ActiveRecordInterface|Closure $arClass The class name of the related record.
      * @param array $link The primary-foreign key constraint.
      * @param bool $multiple Whether this query represents a relation to more than one record.
      *
      * @return ActiveQueryInterface The relational query object.
      *
-     * @psalm-param class-string<ActiveRecordInterface> $arClass
+     * @psalm-param ARClass $arClass
 
      * {@see hasOne()}
      * {@see hasMany()}
      */
-    protected function createRelationQuery(string $arClass, array $link, bool $multiple): ActiveQueryInterface
+    protected function createRelationQuery(string|ActiveRecordInterface|Closure $arClass, array $link, bool $multiple): ActiveQueryInterface
     {
         return $this->instantiateQuery($arClass)->primaryModel($this)->link($link)->multiple($multiple);
     }

src/ActiveQuery.php

@@ -102,6 +102,8 @@
  * These methods may only be called in a relational context. Same is true for {@see inverseOf()}, which marks a relation
  * as inverse of another relation and {@see onCondition()} which adds a condition that's to be added to relational
  * query join condition.
+ *
+ * @psalm-import-type ARClass from ActiveQueryInterface
  */
 class ActiveQuery extends Query implements ActiveQueryInterface
 {
@@ -113,7 +115,7 @@ class ActiveQuery extends Query implements ActiveQueryInterface
     private array $joinWith = [];
 
     /**
-     * @psalm-param class-string<ActiveRecordInterface>|ActiveRecordInterface|Closure $arClass
+     * @psalm-param ARClass $arClass
      */
     final public function __construct(
         protected string|ActiveRecordInterface|Closure $arClass,
@@ -990,7 +992,7 @@ public function getARClassName(): string
     public function getARInstance(): ActiveRecordInterface
     {
         if ($this->arClass instanceof ActiveRecordInterface) {
-            return $this->arClass;
+            return clone $this->arClass;
         }
 
         if ($this->arClass instanceof Closure) {

src/ActiveQueryInterface.php

@@ -22,6 +22,8 @@
  * represents a relation between two active record classes and will return related records only.
  *
  * A class implementing this interface should also use {@see ActiveQueryTrait} and {@see ActiveRelationTrait}.
+ *
+ * @psalm-type ARClass = class-string<ActiveRecordInterface>|ActiveRecordInterface|Closure():ActiveRecordInterface
  */
 interface ActiveQueryInterface extends QueryInterface
 {
@@ -298,6 +300,11 @@ public function getTablesUsedInFrom(): array;
      */
     public function getSql(): string|null;
 
+    /**
+     * @return string|ActiveRecordInterface|Closure The AR class associated with this query.
+     *
+     * @psalm-return ARClass
+     */
     public function getARClass(): string|ActiveRecordInterface|Closure;
 
     /**

tests/ActiveRecordTest.php

@@ -948,4 +948,19 @@ public function testGetDirtyAttributesAfterFind(): void
             $customer->getDirtyAttributes(['id', 'email', 'address', 'status', 'unknown']),
         );
     }
+
+    public function testRelationWithInstance(): void
+    {
+        $this->checkFixture($this->db, 'customer');
+
+        $customerQuery = new ActiveQuery(Customer::class, $this->db);
+        $customer = $customerQuery->findOne(2);
+
+        $orders = $customer->getOrdersUsingInstance();
+
+        $this->assertTrue($customer->isRelationPopulated('ordersUsingInstance'));
+        $this->assertCount(2, $orders);
+        $this->assertSame(2, $orders[0]->getId());
+        $this->assertSame(3, $orders[1]->getId());
+    }
 }

tests/Stubs/ActiveRecord/Customer.php

@@ -53,6 +53,7 @@ public function relationQuery(string $name): ActiveQueryInterface
             'orderItems' => $this->getOrderItemsQuery(),
             'orderItems2' => $this->getOrderItems2Query(),
             'items2' => $this->getItems2Query(),
+            'ordersUsingInstance' => $this->hasMany(new Order($this->db()), ['customer_id' => 'id']),
             default => parent::relationQuery($name),
         };
     }
@@ -261,4 +262,9 @@ public function getItems2Query(): ActiveQuery
         return $this->hasMany(Item::class, ['id' => 'item_id'])
             ->via('orderItems2');
     }
+
+    public function getOrdersUsingInstance(): array
+    {
+        return $this->relation('ordersUsingInstance');
+    }
 }