Entities with construct can be used on Collection and AdminType

There was a problem with entities that defined a constructor
with arguments. It was impossible to use them on Collection and
AdminType because we didn't override the default behavior when
the data is empty.

src/Builder/FormContractor.php

@@ -157,6 +157,9 @@ public function getDefaultOptions($type, FieldDescriptionInterface $fieldDescrip
             $options['delete'] = false;
 
             $options['data_class'] = $fieldDescription->getAssociationAdmin()->getClass();
+            $options['empty_data'] = function () use ($fieldDescription) {
+                return $fieldDescription->getAssociationAdmin()->getNewInstance();
+            };
             $fieldDescription->setOption('edit', $fieldDescription->getOption('edit', 'admin'));
         // NEXT_MAJOR: Check only against FQCNs when dropping support for Symfony 2.8
         } elseif ('sonata_type_collection' === $type || $this->checkFormClass($type, [CollectionType::class])) {
@@ -174,6 +177,9 @@ public function getDefaultOptions($type, FieldDescriptionInterface $fieldDescrip
             $options['type_options'] = [
                 'sonata_field_description' => $fieldDescription,
                 'data_class' => $fieldDescription->getAssociationAdmin()->getClass(),
+                'empty_data' => function () use ($fieldDescription) {
+                    return $fieldDescription->getAssociationAdmin()->getNewInstance();
+                },
             ];
         }
 

tests/Builder/FormContractorTest.php

@@ -64,6 +64,7 @@ public function testDefaultOptionsForSonataFormTypes()
     {
         $admin = $this->createMock(AdminInterface::class);
         $modelManager = $this->createMock(ModelManagerInterface::class);
+        $model = $this->createMock(\stdClass::class);
         $modelClass = 'FooEntity';
 
         $admin->method('getModelManager')->willReturn($modelManager);
@@ -73,6 +74,7 @@ public function testDefaultOptionsForSonataFormTypes()
         $fieldDescription->method('getAdmin')->willReturn($admin);
         $fieldDescription->method('getTargetEntity')->willReturn($modelClass);
         $fieldDescription->method('getAssociationAdmin')->willReturn($admin);
+        $admin->method('getNewInstance')->willReturn($model);
 
         // NEXT_MAJOR: Use only FQCNs when dropping support for Symfony 2.8
         $modelTypes = [
@@ -110,6 +112,7 @@ public function testDefaultOptionsForSonataFormTypes()
             $this->assertSame($modelClass, $options['data_class']);
             $this->assertFalse($options['btn_add']);
             $this->assertFalse($options['delete']);
+            $this->assertSame($model, $options['empty_data']());
         }
 
         // collection type
@@ -121,6 +124,7 @@ public function testDefaultOptionsForSonataFormTypes()
             $this->assertTrue($options['modifiable']);
             $this->assertSame($fieldDescription, $options['type_options']['sonata_field_description']);
             $this->assertSame($modelClass, $options['type_options']['data_class']);
+            $this->assertSame($model, $options['type_options']['empty_data']());
         }
     }