Closes #128: Problem when I use parent:: in trait

src/main/php/PDepend/Source/Builder/Builder.php

@@ -44,6 +44,7 @@
 
 use PDepend\Source\AST\AbstractASTClassOrInterface;
 use PDepend\Source\AST\ASTClass;
+use PDepend\Source\AST\ASTClassOrInterfaceReference;
 use PDepend\Source\AST\ASTFunction;
 use PDepend\Source\AST\ASTInterface;
 use PDepend\Source\AST\ASTTrait;
@@ -233,12 +234,10 @@ public function buildAstSelfReference(AbstractASTClassOrInterface $type);
      *
      * @param \PDepend\Source\AST\ASTClassOrInterfaceReference $reference The type
      *        instance that reference the concrete target of parent.
-     *
      * @return \PDepend\Source\AST\ASTParentReference
      * @since 0.9.6
      */
-    public function buildAstParentReference(
-        \PDepend\Source\AST\ASTClassOrInterfaceReference $reference
+    public function buildAstParentReference(ASTClassOrInterfaceReference $reference
     );
 
     /**

src/main/php/PDepend/Source/Language/PHP/AbstractPHPParser.php

@@ -52,6 +52,7 @@
 use PDepend\Source\AST\ASTNode;
 use PDepend\Source\AST\ASTStatement;
 use PDepend\Source\AST\ASTSwitchStatement;
+use PDepend\Source\AST\ASTTrait;
 use PDepend\Source\AST\ASTValue;
 use PDepend\Source\AST\State;
 use PDepend\Source\Builder\Builder;
@@ -4416,7 +4417,12 @@ private function parseParentReference(Token $token)
             );
         }
 
-        $classReference = $this->classOrInterface->getParentClassReference();
+        if ($this->classOrInterface instanceof ASTTrait) {
+            $classReference = $this->builder->buildAstClassReference('__PDepend_TraitRuntimeReference');
+        } else {
+            $classReference = $this->classOrInterface->getParentClassReference();
+        }
+
         if ($classReference === null) {
             throw new InvalidStateException(
                 $token->startLine,

src/test/php/PDepend/Source/AST/ASTTraitTest.php

@@ -358,6 +358,28 @@ public function testGetMethodsReturnsExpectedNumberOfMethods()
         $this->assertEquals(3, count($trait->getMethods()));
     }
 
+    /**
+     * testTraitCanUseParentKeywordInMethodBody
+     *
+     * @return void
+     */
+    public function testTraitCanUseParentKeywordInMethodBody()
+    {
+        $trait = $this->getFirstTraitForTest();
+        $this->assertNotNull($trait);
+    }
+
+    /**
+     * testTraitCanUseParentKeywordAsMethodTypeHint
+     *
+     * @return void
+     */
+    public function testTraitCanUseParentKeywordAsMethodTypeHint()
+    {
+        $trait = $this->getFirstTraitForTest();
+        $this->assertNotNull($trait);
+    }
+
     /**
      * testAcceptInvokesVisitTraitOnGivenVisitor
      *

src/test/resources/files/Source/AST/ASTTrait/testTraitCanUseParentKeywordAsMethodTypeHint.php

@@ -0,0 +1,21 @@
+<?php
+trait testTraitCanUseParentKeywordAsMethodTypeHint
+{
+    public function baz(parent $foo)
+    {
+        echo get_class($foo), PHP_EOL;
+    }
+}
+
+class Foo {
+    use testTraitCanUseParentKeywordAsMethodTypeHint;
+}
+
+class Bar {
+    use testTraitCanUseParentKeywordAsMethodTypeHint;
+}
+
+$foo = new Foo();
+$bar = new Bar();
+
+$foo->baz($foo);

src/test/resources/files/Source/AST/ASTTrait/testTraitCanUseParentKeywordInMethodBody.php

@@ -0,0 +1,8 @@
+<?php
+trait testTraitCanUseParentKeywordInMethodBody
+{
+    public function foo()
+    {
+        parent::foo();
+    }
+}