MethodReflector: move method return type resolving

packages/NodeTypeResolver/src/PerNodeTypeResolver/MethodCallTypeResolver.php

@@ -0,0 +1,137 @@
+<?php declare(strict_types=1);
+
+namespace Rector\NodeTypeResolver\PerNodeTypeResolver;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Assign;
+use PhpParser\Node\Expr\MethodCall;
+use PhpParser\Node\Expr\PropertyFetch;
+use PhpParser\Node\Expr\Variable;
+use Rector\BetterReflection\Reflector\MethodReflector;
+use Rector\Node\Attribute;
+use Rector\NodeTypeResolver\Contract\NodeTypeResolverAwareInterface;
+use Rector\NodeTypeResolver\Contract\PerNodeTypeResolver\PerNodeTypeResolverInterface;
+use Rector\NodeTypeResolver\NodeTypeResolver;
+use Rector\NodeTypeResolver\TypeContext;
+
+final class AssignTypeResolver implements PerNodeTypeResolverInterface, NodeTypeResolverAwareInterface
+{
+    /**
+     * @var TypeContext
+     */
+    private $typeContext;
+
+    /**
+     * @var NodeTypeResolver
+     */
+    private $nodeTypeResolver;
+
+    /**
+     * @var MethodReflector
+     */
+    private $methodReflector;
+
+    public function __construct(TypeContext $typeContext, MethodReflector $methodReflector)
+    {
+        $this->typeContext = $typeContext;
+        $this->methodReflector = $methodReflector;
+    }
+
+    public function getNodeClass(): string
+    {
+        return Assign::class;
+    }
+
+    /**
+     * @param Assign $assignNode
+     */
+    public function resolve(Node $assignNode): ?string
+    {
+        if (! $assignNode->var instanceof Variable) {
+            return null;
+        }
+
+        // $var = $anotherVar;
+        if ($assignNode->expr instanceof Variable) {
+            return $this->processAssignVariableNode($assignNode);
+        }
+
+        if ($assignNode->expr instanceof MethodCall) {
+            return $this->processAssignMethodReturn($assignNode);
+        }
+
+        return null;
+    }
+
+    public function setNodeTypeResolver(NodeTypeResolver $nodeTypeResolver): void
+    {
+        $this->nodeTypeResolver = $nodeTypeResolver;
+    }
+
+    private function processAssignVariableNode(Assign $assignNode): ?string
+    {
+        if ($assignNode->var->name instanceof Variable) {
+            $name = $assignNode->var->name->name;
+        } else {
+            $name = $assignNode->var->name;
+        }
+
+        $this->typeContext->addAssign($name, $assignNode->expr->name);
+
+        $variableType = $this->typeContext->getTypeForVariable($name);
+        if ($variableType) {
+            $assignNode->var->setAttribute(Attribute::TYPE, $variableType);
+
+            return $variableType;
+        }
+
+        return null;
+    }
+
+    private function processAssignMethodReturn(Assign $assignNode): ?string
+    {
+        $variableType = null;
+
+        // 1. get $anotherVar type
+
+        /** @var Variable|mixed $methodCallVariable */
+        $methodCallVariable = $assignNode->expr->var;
+
+        if (! $methodCallVariable instanceof Variable) {
+            return null;
+        }
+
+        $methodCallVariableName = $methodCallVariable->name;
+
+        $methodCallVariableType = $this->typeContext->getTypeForVariable($methodCallVariableName);
+
+        $methodCallName = $this->resolveMethodCallName($assignNode);
+
+        // 2. get method() return type
+        if (! $methodCallVariableType || ! $methodCallName) {
+            return null;
+        }
+
+        $variableType = $this->methodReflector->getMethodReturnType($methodCallVariableType, $methodCallName);
+        if ($variableType) {
+            $variableName = $assignNode->var->name;
+            $this->typeContext->addVariableWithType($variableName, $variableType);
+        }
+
+        return $variableType;
+    }
+
+    private function resolveMethodCallName(Assign $assignNode): ?string
+    {
+        if ($assignNode->expr->name instanceof Variable) {
+            return $assignNode->expr->name->name;
+        }
+
+        if ($assignNode->expr->name instanceof PropertyFetch) {
+            // not implemented yet
+            return null;
+        }
+
+        return (string) $assignNode->expr->name;
+    }
+}