Fix bugs in refactor

src/Psalm/Checker/ClassChecker.php

@@ -8,6 +8,11 @@ use Psalm\Context;
 
 class ClassChecker extends ClassLikeChecker
 {
+    /**
+     * @var PhpParser\Node\Stmt\Class_
+     */
+    protected $class;
+
     /**
      * A lookup table of existing classes
      * @var array

src/Psalm/Checker/FunctionChecker.php

@@ -325,7 +325,7 @@ class FunctionChecker extends FunctionLikeChecker
                 new Type\Generic('array',
                     [
                         Type::getInt(),
-                        clone $call_args[0]->value->inferredType->type_paams[1]
+                        clone $call_args[0]->value->inferredType->types['array']->type_params[1]
                     ]
                 )
             ]);

src/Psalm/Checker/FunctionLikeChecker.php

@@ -535,8 +535,8 @@ abstract class FunctionLikeChecker implements StatementsSource
             $param_name,
             $param->isPassedByReference(),
             $param_type,
-            $is_nullable,
-            $is_optional
+            $is_optional,
+            $is_nullable
         );
     }
 

src/Psalm/Checker/StatementsChecker.php

@@ -1546,7 +1546,7 @@ class StatementsChecker
         }
 
         if ($var_id) {
-            $context->vars_in_scope[$var_id] = $stmt->inferredType;
+            $context->vars_in_scope[$var_id] = isset($stmt->inferredType) ? $stmt->inferredType : Type::getMixed();
         }
     }
 
@@ -1722,6 +1722,19 @@ class StatementsChecker
                 );
 
                 if (!isset($class_properties[$prop_name])) {
+                    if ($stmt->var->name === 'this') {
+                        if (IssueBuffer::accepts(
+                            new UndefinedThisProperty(
+                                'Instance property ' . $lhs_type_part->value . '::' . $prop_name . ' is not defined',
+                                $this->checked_file_name,
+                                $stmt->getLine()
+                            ),
+                            $this->suppressed_issues
+                        )) {
+                            return false;
+                        }
+                    }
+                    else {
                         if (IssueBuffer::accepts(
                             new UndefinedProperty(
                                 'Instance property ' . $lhs_type_part->value . '::' . $prop_name . ' is not defined',
@@ -1732,6 +1745,7 @@ class StatementsChecker
                         )) {
                             return false;
                         }
+                    }
 
                     continue;
                 }
@@ -3204,7 +3218,7 @@ class StatementsChecker
             foreach ($args as $i => $arg) {
                 $method_param = $method_params[$i];
 
-                if ($return_type->value === '$' . $method_param['name']) {
+                if ($return_type->value === '$' . $method_param->name) {
                     $arg_value = $arg->value;
                     if ($arg_value instanceof PhpParser\Node\Scalar\String_) {
                         $return_type->value = preg_replace('/^\\\/', '', $arg_value->value);

src/Psalm/FunctionLikeParameter.php

@@ -19,7 +19,7 @@ class FunctionLikeParameter
     /** @var bool */
     public $is_nullable;
 
-    public function __construct($name, $by_ref, $type, $is_optional = false, $is_nullable = false)
+    public function __construct($name, $by_ref, $type, $is_optional = true, $is_nullable = false)
     {
         $this->name = $name;
         $this->by_ref = $by_ref;