From 152d1512f16ee9fe91ba4561a43543994873d089 Mon Sep 17 00:00:00 2001
From: Matthew Brown <github@muglug.com>
Date: Mon, 12 Jun 2017 22:51:39 -0400
Subject: [PATCH] Fix issue capturing method mutations in traits

---
 src/Psalm/Checker/ProjectChecker.php | 10 ++++----
 tests/MethodMutationTest.php         | 38 ++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/src/Psalm/Checker/ProjectChecker.php b/src/Psalm/Checker/ProjectChecker.php
index a8310dad8..351592408 100644
--- a/src/Psalm/Checker/ProjectChecker.php
+++ b/src/Psalm/Checker/ProjectChecker.php
@@ -908,11 +908,11 @@ class ProjectChecker
 
         $file_checker = $this->getVisitedFileCheckerForClassLike($fq_class_name);
 
-        $declaring_method_id = (string)MethodChecker::getDeclaringMethodId($original_method_id);
-        list($declaring_fq_class_name) = explode('::', $declaring_method_id);
+        $appearing_method_id = (string)MethodChecker::getAppearingMethodId($original_method_id);
+        list($appearing_fq_class_name) = explode('::', $appearing_method_id);
 
-        if (strtolower($declaring_fq_class_name) !== strtolower($fq_class_name)) {
-            $file_checker = $this->getVisitedFileCheckerForClassLike($declaring_fq_class_name);
+        if (strtolower($appearing_fq_class_name) !== strtolower($fq_class_name)) {
+            $file_checker = $this->getVisitedFileCheckerForClassLike($appearing_fq_class_name);
         }
 
         $file_checker->analyze(false, true);
@@ -922,7 +922,7 @@ class ProjectChecker
             $this_context->vars_in_scope['$this'] = Type::parseString($fq_class_name);
         }
 
-        $file_checker->getMethodMutations($declaring_method_id, $this_context);
+        $file_checker->getMethodMutations($appearing_method_id, $this_context);
     }
 
     /**
diff --git a/tests/MethodMutationTest.php b/tests/MethodMutationTest.php
index 5dbb19394..8aa2f0191 100644
--- a/tests/MethodMutationTest.php
+++ b/tests/MethodMutationTest.php
@@ -136,4 +136,42 @@ class MethodMutationTest extends TestCase
 
         $this->assertSame('Foo', (string)$method_context->vars_in_scope['$this->foo']);
     }
+
+    /**
+     * @return void
+     */
+    public function testTraitMethod()
+    {
+        $this->project_checker->registerFile(
+            'somefile.php',
+            '<?php
+        class Foo { }
+
+        trait T {
+            private function setFoo() : void {
+                $this->foo = new Foo();
+            }
+        }
+
+        class FooController {
+            use T;
+
+            /** @var Foo|null */
+            public $foo;
+
+            public function __construct() {
+                $this->setFoo();
+            }
+        }'
+        );
+
+        $file_checker = new FileChecker('somefile.php', $this->project_checker);
+        $context = new Context();
+        $file_checker->visit($context);
+        $file_checker->analyze(false, true);
+        $method_context = new Context();
+        $this->project_checker->getMethodMutations('FooController::__construct', $method_context);
+
+        $this->assertSame('Foo', (string)$method_context->vars_in_scope['$this->foo']);
+    }
 }