From 5c132ba8b8aa34d02f0e8c0cc27ed08c9f498803 Mon Sep 17 00:00:00 2001
From: Matthew Brown <github@muglug.com>
Date: Tue, 1 Nov 2016 10:28:09 -0400
Subject: [PATCH] Fix a few type errors

---
 src/Psalm/Type.php           |  6 +++---
 src/Psalm/Type/ParseTree.php | 13 +++++++++++--
 src/Psalm/Type/Union.php     |  8 +-------
 3 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/src/Psalm/Type.php b/src/Psalm/Type.php
index aa3852dbc..346f62ba3 100644
--- a/src/Psalm/Type.php
+++ b/src/Psalm/Type.php
@@ -401,10 +401,10 @@ abstract class Type
             throw new \InvalidArgumentException('You must pass at least one type to combineTypes');
         }
 
-        /** @var array<string,array<string,Union>> */
+        /** @var array<string, array<string, Union>> */
         $key_types = [];
 
-        /** @var array<string,array<string,Union>> */
+        /** @var array<string, array<string, Union>> */
         $value_types = [];
 
         foreach ($types as $type) {
@@ -447,7 +447,7 @@ abstract class Type
             }
             elseif ($type instanceof ObjectLike) {
                 if (!isset($value_types['object-like'])) {
-                    /** @var array<string,Union> */
+                    /** @var array<string, Union> */
                     $value_types['object-like'] = [];
                 }
 
diff --git a/src/Psalm/Type/ParseTree.php b/src/Psalm/Type/ParseTree.php
index c47b46a4a..3bd2f29d8 100644
--- a/src/Psalm/Type/ParseTree.php
+++ b/src/Psalm/Type/ParseTree.php
@@ -99,8 +99,12 @@ class ParseTree
                         throw new \InvalidArgumentException('Cannot parse comma in non-generic/array type');
                     }
 
+                    if (!$current_parent) {
+                        throw new \InvalidArgumentException('Cannot parse comma in with no parent node');
+                    }
+
                     if ($context_node->value === self::GENERIC && $current_parent->value !== self::GENERIC) {
-                        if (!$current_parent->parent->value) {
+                        if (!isset($current_parent->parent) || !$current_parent->parent->value) {
                             throw new \InvalidArgumentException('Cannot parse comma in non-generic/array type');
                         }
 
@@ -110,7 +114,7 @@ class ParseTree
                         do {
                             $current_leaf = $current_leaf->parent;
                         }
-                        while ($current_leaf->parent->value !== self::OBJECT_LIKE);
+                        while ($current_leaf->parent && $current_leaf->parent->value !== self::OBJECT_LIKE);
                     }
 
                     break;
@@ -163,6 +167,11 @@ class ParseTree
                     }
 
                     $new_leaf = new self($type_token, $current_leaf->parent);
+
+                    if (!isset($current_leaf->parent)) {
+                        throw new \InvalidArgumentException('Current leaf must have a parent');
+                    }
+
                     $current_leaf->parent->children[] = $new_leaf;
 
                     $current_leaf = $new_leaf;
diff --git a/src/Psalm/Type/Union.php b/src/Psalm/Type/Union.php
index ef72f31ba..cfbb944ec 100644
--- a/src/Psalm/Type/Union.php
+++ b/src/Psalm/Type/Union.php
@@ -160,13 +160,7 @@ class Union extends Type
     /** @return bool */
     public function isEmpty()
     {
-        if ($this instanceof Atomic) {
-            return $this->value === 'empty';
-        }
-
-        if ($this instanceof Union) {
-            return isset($this->types['empty']);
-        }
+        return isset($this->types['empty']);
     }
 
     public function removeObjects()