Add dynamic return typing to Mage_Core_Model_Layout class helpers

Author: andytson-inviqa

extension.neon

@@ -8,11 +8,15 @@ parameters:
         - %currentWorkingDirectory%/public/app/code/local/*/*/sql/*
 
 services:
-    -
-        class: PHPStanMagento1\Type\Mage\HelperMethodsReturnTypeExtension
-        tags:
-            - phpstan.broker.dynamicStaticMethodReturnTypeExtension
     -
         class: PHPStanMagento1\Reflection\Varien\Object\MagicMethodsReflectionExtension
         tags:
             - phpstan.broker.methodsClassReflectionExtension
+    -
+        class: PHPStanMagento1\Type\Mage\Core\Model\Layout\HelperMethodsReturnTypeExtension
+        tags:
+            - phpstan.broker.dynamicMethodReturnTypeExtension
+    -
+        class: PHPStanMagento1\Type\Mage\HelperMethodsReturnTypeExtension
+        tags:
+            - phpstan.broker.dynamicStaticMethodReturnTypeExtension

src/Type/Mage/Core/Model/Layout/HelperMethodsReturnTypeExtension.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace PHPStanMagento1\Type\Mage;
+
+use PhpParser\Node\Expr\StaticCall;
+use PhpParser\Node\Scalar\String_;
+use PHPStan\Analyser\Scope;
+use PHPStan\Reflection\MethodReflection;
+use PHPStan\ShouldNotHappenException;
+use PHPStan\Type\DynamicMethodReturnTypeExtension;
+use PHPStan\Type\ObjectType;
+use PHPStan\Type\Type;
+
+use Mage_Core_Model_Layout;
+
+class HelperMethodsReturnTypeExtension implements DynamicMethodReturnTypeExtension
+{
+    public function getClass(): string
+    {
+        return Mage_Core_Model_Layout;
+    }
+
+    public function isStaticMethodSupported(MethodReflection $methodReflection): bool
+    {
+        return in_array(
+            $methodReflection->getName(),
+            [
+                'getBlockSingleton',
+                'helper',
+            ]
+        );
+    }
+
+    public function getTypeFromStaticMethodCall(MethodReflection $methodReflection, StaticCall $methodCall, Scope $scope): Type
+    {
+        if (!isset($methodCall->args[0]) || !$methodCall->args[0]->value instanceof String_) {
+            throw new ShouldNotHappenException();
+        }
+
+        $name = $methodCall->args[0]->value->value;
+        $class = $this->getClassFromHelperMethod($methodReflection->getName(), $name);
+        return new ObjectType($class);
+    }
+
+    private function getClassFromHelperMethod($method, $name)
+    {
+        $config = Mage::getConfig();
+        switch ($method) {
+            case 'getBlockSingleton':
+                return $config->getBlockClassName($name);
+            case 'helper':
+                return $config->getHelperClassName($name);
+        }
+        throw new ShouldNotHappenException();
+    }
+}