Fix #114 - add optional Hack-like checks calls

config.xsd

@@ -26,6 +26,7 @@
         <xs:attribute name="requireVoidReturnType" type="xs:string" />
         <xs:attribute name="useAssertForType" type="xs:string" />
         <xs:attribute name="cacheFileContentHashes" type="xs:string" />
+        <xs:attribute name="rememberPropertyAssignmentsAfterCall" type="xs:string" />
     </xs:complexType>
 
     <xs:complexType name="ProjectFilesType">

psalm.xml

@@ -5,6 +5,7 @@
     useDocblockTypes="true"
     totallyTyped="true"
     strictBinaryOperands="false"
+    rememberPropertyAssignmentsAfterCall="true"
 >
     <projectFiles>
         <directory name="src" />

src/Psalm/Checker/Statements/Block/ForChecker.php

@@ -49,7 +49,7 @@ class ForChecker
         }
 
         foreach ($context->vars_in_scope as $var => $type) {
-            if ($type->isMixed()) {
+            if ($type->isMixed() || !isset($for_context->vars_in_scope[$var])) {
                 continue;
             }
 

src/Psalm/Checker/Statements/Expression/CallChecker.php

@@ -296,6 +296,8 @@ class CallChecker
             // fall through
         }
 
+        $config = Config::getInstance();
+
         if ($function_exists) {
             $generic_params = null;
 
@@ -326,8 +328,6 @@ class CallChecker
                 }
             }
 
-            $config = Config::getInstance();
-
             if ($stmt->name instanceof PhpParser\Node\Name && $method_id) {
                 if (!$in_call_map || $is_stubbed) {
                     if ($function_storage && $function_storage->template_types) {
@@ -424,6 +424,10 @@ class CallChecker
             }
         }
 
+        if (!$config->remember_property_assignments_after_call && !$context->collect_initializations) {
+            $context->removeAllObjectVars();
+        }
+
         if ($stmt->name instanceof PhpParser\Node\Name &&
             ($stmt->name->parts === ['get_class'] || $stmt->name->parts === ['gettype']) &&
             $stmt->args
@@ -609,6 +613,12 @@ class CallChecker
             }
         }
 
+        $config = Config::getInstance();
+
+        if (!$config->remember_property_assignments_after_call && !$context->collect_initializations) {
+            $context->removeAllObjectVars();
+        }
+
         return null;
     }
 
@@ -918,6 +928,10 @@ class CallChecker
                 $statements_checker
             );
         }
+
+        if (!$config->remember_property_assignments_after_call && !$context->collect_initializations) {
+            $context->removeAllObjectVars();
+        }
     }
 
     /**
@@ -1253,6 +1267,10 @@ class CallChecker
                 $statements_checker
             );
         }
+
+        if (!$config->remember_property_assignments_after_call && !$context->collect_initializations) {
+            $context->removeAllObjectVars();
+        }
     }
 
     /**

src/Psalm/Config.php

@@ -168,6 +168,11 @@ class Config
      */
     public $use_assert_for_type = false;
 
+    /**
+     * @var boolean
+     */
+    public $remember_property_assignments_after_call = true;
+
     /**
      * Psalm plugins
      *
@@ -323,6 +328,11 @@ class Config
             $config->cache_file_hashes_during_run = $attribute_text === 'true' || $attribute_text === '1';
         }
 
+        if (isset($config_xml['rememberPropertyAssignmentsAfterCall'])) {
+            $attribute_text = (string) $config_xml['rememberPropertyAssignmentsAfterCall'];
+            $config->remember_property_assignments_after_call = $attribute_text === 'true' || $attribute_text === '1';
+        }
+
         if (isset($config_xml->projectFiles)) {
             $config->project_files = ProjectFileFilter::loadFromXMLElement($config_xml->projectFiles, true);
         }

src/Psalm/Context.php

@@ -361,6 +361,51 @@ class Context
         }
     }
 
+    /**
+     * @return void
+     */
+    public function removeAllObjectVars()
+    {
+        $vars_to_remove = [];
+
+        foreach ($this->vars_in_scope as $var_id => $_) {
+            if (strpos($var_id, '->') !== false || strpos($var_id, '::') !== false) {
+                $vars_to_remove[] = $var_id;
+            }
+        }
+
+        if (!$vars_to_remove) {
+            return;
+        }
+
+        foreach ($vars_to_remove as $var_id) {
+            unset($this->vars_in_scope[$var_id]);
+        }
+
+        $clauses_to_keep = [];
+
+        foreach ($this->clauses as $clause) {
+            $abandon_clause = false;
+
+            foreach (array_keys($clause->possibilities) as $key) {
+                if (strpos($key, '->') !== false || strpos($key, '::') !== false) {
+                    $abandon_clause = true;
+                    break;
+                }
+            }
+
+            if (!$abandon_clause) {
+                $clauses_to_keep[] = $clause;
+            }
+        }
+
+        $this->clauses = $clauses_to_keep;
+
+        if ($this->parent_context) {
+            $this->parent_context->removeAllObjectVars();
+        }
+    }
+
     /**
      * @param   Context $op_context
      * @return  void

tests/PropertyTypeTest.php

@@ -1072,4 +1072,38 @@ class PropertyTypeTest extends PHPUnit_Framework_TestCase
         $file_checker = new FileChecker('somefile.php', $this->project_checker, $stmts);
         $file_checker->visitAndAnalyzeMethods();
     }
+
+    /**
+     * @expectedException        \Psalm\Exception\CodeException
+     * @expectedExceptionMessage InvalidReturnType
+     * @return                   void
+     */
+    public function testForgetPropertyAssignments()
+    {
+        Config::getInstance()->remember_property_assignments_after_call = false;
+
+        $stmts = self::$parser->parse('<?php
+        class X {
+            /** @var ?int **/
+            private $x;
+
+            public function getX(): int {
+                if ($this->x === null) {
+                    $this->x = 0;
+                }
+                $this->modifyX();
+                return $this->x;
+            }
+
+            private function modifyX(): void {
+                $this->x = null;
+            }
+        }
+        ');
+
+        $file_checker = new FileChecker('somefile.php', $this->project_checker, $stmts);
+        $file_checker->visitAndAnalyzeMethods();
+    }
+
+
 }