From 117a4d4d4001938bb2f11df51f2ada1b99933cc6 Mon Sep 17 00:00:00 2001
From: Brown <github@muglug.com>
Date: Thu, 30 Apr 2020 23:35:13 -0400
Subject: [PATCH] Require callable() have a return type when in conditional

Fixes #3260
---
 src/Psalm/Internal/Type/ParseTree.php |  4 ++++
 src/Psalm/Type.php                    |  4 ++++
 tests/TypeParseTest.php               | 34 ++++++++++++++++++++++++++-
 3 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/src/Psalm/Internal/Type/ParseTree.php b/src/Psalm/Internal/Type/ParseTree.php
index ebd9a9b99..f285335d0 100644
--- a/src/Psalm/Internal/Type/ParseTree.php
+++ b/src/Psalm/Internal/Type/ParseTree.php
@@ -340,6 +340,10 @@ class ParseTree
                     }
 
                     if ($current_parent && $current_parent instanceof ParseTree\ConditionalTree) {
+                        if (count($current_parent->children) > 1) {
+                            throw new TypeParseTreeException('Cannot process colon in conditional twice');
+                        }
+
                         $current_leaf = $current_parent;
                         $current_parent = $current_parent->parent;
                         break;
diff --git a/src/Psalm/Type.php b/src/Psalm/Type.php
index ec2d47579..e9972d1f9 100644
--- a/src/Psalm/Type.php
+++ b/src/Psalm/Type.php
@@ -859,6 +859,10 @@ abstract class Type
                 throw new TypeParseTreeException('Unrecognized template \'' . $template_param_name . '\'');
             }
 
+            if (count($parse_tree->children) !== 2) {
+                throw new TypeParseTreeException('Invalid conditional');
+            }
+
             $first_class = array_keys($template_type_map[$template_param_name])[0];
 
             $conditional_type = self::getTypeFromTree(
diff --git a/tests/TypeParseTest.php b/tests/TypeParseTest.php
index 72db8eb94..82764d5ed 100644
--- a/tests/TypeParseTest.php
+++ b/tests/TypeParseTest.php
@@ -714,6 +714,26 @@ class TypeParseTest extends TestCase
         );
     }
 
+    /**
+     * @return void
+     */
+    public function testConditionalTypeWithCallableElseBool()
+    {
+        $this->expectException(\Psalm\Exception\TypeParseTreeException::class);
+        Type::parseString('(T is string ? callable() : bool)', null, ['T' => ['' => [Type::getArray()]]]);
+    }
+
+    /**
+     * @return void
+     */
+    public function testConditionalTypeWithCallableReturningBoolElseBool()
+    {
+        $this->assertSame(
+            '(T is string ? callable():bool : bool)',
+            (string) Type::parseString('(T is string ? (callable() : bool) : bool)', null, ['T' => ['' => [Type::getArray()]]])
+        );
+    }
+
     public function testConditionalTypeWithGenerics() : void
     {
         $this->assertSame(
@@ -726,7 +746,19 @@ class TypeParseTest extends TestCase
         );
     }
 
-    public function testConditionalTypeWithCallable() : void
+    public function testConditionalTypeWithCallableBracketed() : void
+    {
+        $this->assertSame(
+            '(T is string ? callable(string, string):string : callable(mixed...):mixed)',
+            (string) Type::parseString(
+                '(T is string ? (callable(string, string):string) : (callable(mixed...):mixed))',
+                null,
+                ['T' => ['' => [Type::getArray()]]]
+            )
+        );
+    }
+
+    public function testConditionalTypeWithCallableNotBracketed() : void
     {
         $this->assertSame(
             '(T is string ? callable(string, string):string : callable(mixed...):mixed)',