Fatal Error from FormTypeImplicit when using method call from variable (#105)

* Issue #104 : calling method contained in variable (in Form context) causes parsing process to raise "Catchable Fatal Error: Object of class PhpParser\Node\Expr\Variable could not be converted to string"

* Issue #104 : code style fix

* Issue #104 : code style fix

* changes requested by @Nyholm during review

Author: noofaq

Changelog.md

@@ -4,6 +4,12 @@ The change log describes what is "Added", "Removed", "Changed" or "Fixed" betwee
 
 ## UNRELEASED
 
+## 1.5.2
+
+### Fixed
+
+- Fixed Fatal Error in FormTypeImplicit when using method call from variable 
+
 ## 1.5.1
 
 ### Fixed

src/Visitor/Php/Symfony/FormTypeLabelImplicit.php

@@ -32,6 +32,7 @@ public function enterNode(Node $node)
         $domain = null;
         // use add() function and look at first argument and if that's a string
         if ($node instanceof Node\Expr\MethodCall
+            && (!is_object($node->name) || method_exists($node->name, '__toString'))
             && ('add' === (string) $node->name || 'create' === (string) $node->name)
             && $node->args[0]->value instanceof Node\Scalar\String_) {
             $skipLabel = false;

tests/Resources/Github/Issue_104.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Translation\Extractor\Tests\Resources\Php\Symfony;
+
+class Issue104Type
+{
+    public function buildForm(FormBuilderInterface $builder, array $options)
+    {
+        $model = new \stdClass();
+        $setter = 'setMethod';
+        $model->$setter(null);
+    }
+}