Avoid model getting overwritten when calling with()

src/Repository/Eloquent/BaseRepository.php

@@ -28,7 +28,7 @@ public function __construct(ApplicationContract $app, Collection $collection, $m
         $this->app = $app;
         $this->criteria = $collection;
 
-        if (null !== $model && true === $model instanceof Model) {
+        if (null !== $model && true === \is_object($model)) {
             $this->model = $model;
         }
 
@@ -177,7 +177,9 @@ public function with($relations)
     {
         $this->initiateModel();
 
-        return parent::with($relations);
+        $this->model->with($relations);
+
+        return $this;
     }
 
     public function withCount($relations)

tests/BaseRepositoryTest.php

@@ -117,6 +117,24 @@ public function testResetModelCreatesNewModel()
         $this->assertNotSame($model, $property->getValue($repository));
     }
 
+    public function testWithDoesntOverwrite()
+    {
+        $repository = new RepositoryStub(
+            $this->application,
+            new \Illuminate\Support\Collection(),
+            $model = m::mock('alias:ModelStub')
+        );
+
+        $model->shouldReceive('with')->andReturn(m::mock(\Illuminate\Database\Eloquent\Builder::class));
+
+        $reflectionClass = $this->repositoryReflector();
+        $property = $reflectionClass->getProperty('model');
+        $property->setAccessible(true);
+
+        $this->assertInstanceOf(RepositoryStub::class, $repository->with(['relation']));
+        $this->assertSame($model, $property->getValue($repository));
+    }
+
     public function providerTestConstructor(): array
     {
         return [