set correct Factory when autoAddInvokableClass=true

src/FormElementManager/FormElementManagerTrait.php

@@ -35,6 +35,18 @@ public function get($name, $options = [], $usePeeringServiceManagers = true)
         if (is_string($options)) {
             $options = ['name' => $options];
         }
+
+        if (! $this->has($name)) {
+            if (! $this->autoAddInvokableClass || ! class_exists($name)) {
+                throw new Exception\InvalidElementException(sprintf(
+                    'A plugin by the name "%s" was not found in the plugin manager %s',
+                    $name,
+                    get_class($this)
+                ));
+            }
+
+            $this->setInvokableClass($name, $name);
+        }
         return parent::get($name, $options, $usePeeringServiceManagers);
     }
 

test/FormElementManagerTest.php

@@ -222,6 +222,18 @@ public function testAddingInvokableCreatesAliasAndMapsClassToElementFactory()
         }
     }
 
+    public function testAutoAddInvokableClass()
+    {
+        $instance = $this->manager->get(
+            TestAsset\ConstructedElement::class,
+            ['constructedKey' => 'constructedKey']
+        );
+        $this->assertEquals('constructedelement', $instance->getName());
+        $this->assertEquals([
+            'constructedKey' => 'constructedKey'
+        ], $instance->getOptions());
+    }
+
     public function testAllAliasesShouldBeCanonicalized()
     {
         if (method_exists($this->manager, 'configure')) {

test/TestAsset/ConstructedElement.php

@@ -0,0 +1,27 @@
+<?php
+/**
+ * @see       https://github.com/zendframework/zend-navigation for the canonical source repository
+ * @copyright Copyright (c) 2017 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   https://github.com/zendframework/zend-form/blob/master/LICENSE.md New BSD License
+ */
+
+namespace ZendTest\Form\TestAsset;
+
+use Zend\Form\Element;
+
+class ConstructedElement extends Element
+{
+    public $constructedKey;
+
+    /**
+     * @param null|int|string $name
+     * @param array $options
+     */
+    public function __construct($name = null, $options = [])
+    {
+        if (isset($options['constructedKey'])) {
+            $this->constructedKey = $options['constructedKey'];
+        }
+        parent::__construct($name, $options);
+    }
+}