From 330199c9a3fd9de5e1f27f8d0f2fbb4f46ffb790 Mon Sep 17 00:00:00 2001
From: Matthew Brown <github@muglug.com>
Date: Wed, 31 Aug 2016 15:10:11 -0400
Subject: [PATCH] Add support for callable checks

---
 src/Psalm/Checker/TypeChecker.php | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/Psalm/Checker/TypeChecker.php b/src/Psalm/Checker/TypeChecker.php
index 8d5af5cc1..0e2c69b9e 100644
--- a/src/Psalm/Checker/TypeChecker.php
+++ b/src/Psalm/Checker/TypeChecker.php
@@ -318,6 +318,12 @@ class TypeChecker
                         $if_types[$var_name] = '!scalar';
                     }
                 }
+                else if (self::hasCallableCheck($conditional->expr)) {
+                    $var_name = StatementsChecker::getVarId($conditional->expr->args[0]->value);
+                    if ($var_name) {
+                        $if_types[$var_name] = '!callable';
+                    }
+                }
             }
             else if ($conditional->expr instanceof PhpParser\Node\Expr\Isset_) {
                 foreach ($conditional->expr->vars as $isset_var) {
@@ -485,6 +491,12 @@ class TypeChecker
                     $if_types[$var_name] = 'scalar';
                 }
             }
+            else if (self::hasCallableCheck($conditional)) {
+                $var_name = StatementsChecker::getVarId($conditional->args[0]->value);
+                if ($var_name) {
+                    $if_types[$var_name] = 'callable';
+                }
+            }
         }
         else if ($conditional instanceof PhpParser\Node\Expr\Empty_) {
             $var_name = StatementsChecker::getVarId($conditional->expr);
@@ -686,6 +698,18 @@ class TypeChecker
         return false;
     }
 
+    /**
+     * @return bool
+     */
+    protected static function hasCallableCheck(PhpParser\Node\Expr\FuncCall $stmt)
+    {
+        if ($stmt->name instanceof PhpParser\Node\Name && $stmt->name->parts === ['is_callable']) {
+            return true;
+        }
+
+        return false;
+    }
+
     /**
      * Takes two arrays and consolidates them, removing null values from existing types where applicable
      *