[DeadCode] Anonymous class implementing an interface doesn't respect interface signature

[pierredup]

I found this while running the dead code level on a code base. I don't have a fix for it yet, but thought I'd open a PR so long with a failing test case while I investigate further (and maybe get some pointers to the right solution)

When instantiating an anonymous class that implements an interface, and the methods in the class is empty, then all the parameters in the method signature is removed. The signature that comes from the interface isn't respected. When running the test case in the PR, I get the following failure:

Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
         {
             $class = new class implements Foo
             {
-                public function bar($value1)
+                public function bar()
                 {
                 }
             };\n

but I expect the test to pass, since the function bar matches the signature in the interface it implements.

The strange thing, though, is that in the RemoveUnusedParameterRector class, the line $classNode = $node->getAttribute(AttributeKey::CLASS_NODE); returns the current class node, and not the anonymous class node. So I think the issue might lie when traversing the nodes, and not with the actual rector class. I'm still digging through everything, but any nudge in the right direction would be appreciated.

[TomasVotruba]

There are many edge-cases in anonymous classes, that are hard to resolve right.
I think anonymous classes should be skipped by this rule.

As for the incorrect class node: each node is decorated by it's parent node:

rector/packages/NodeTypeResolver/src/NodeVisitor/ClassAndMethodNodeVisitor.php

Line 72 in ea1a151

$node->setAttribute(AttributeKey::CLASS_NODE, $this->classNode);

The class is probably incorrectly resolved here:

rector/packages/NodeTypeResolver/src/NodeVisitor/ClassAndMethodNodeVisitor.php

Line 55 in ea1a151

if ($node instanceof Class_ && $this->isClassAnonymous($node)) {

[pierredup]

Thanks @TomasVotruba, I updated the PR with a patch for handling methods on an anonymous class.

[TomasVotruba]

Thank you, looks good 👍