Interpret variadic params as arrays

src/Psalm/Checker/FunctionLikeChecker.php

@@ -571,6 +571,18 @@ abstract class FunctionLikeChecker implements StatementsSource
                 }
 
                 $param_type = Type::parseString($param_type_string);
+
+                if ($param->variadic) {
+                    $param_type = new Type\Union([
+                        new Type\GenericArray(
+                            'array',
+                            [
+                                Type::getInt(),
+                                $param_type
+                            ]
+                        )
+                    ]);
+                }
             }
         }
 

tests/Php56Test.php

@@ -93,6 +93,25 @@ class Php56Test extends PHPUnit_Framework_TestCase
         $file_checker->check(true, true, $context);
     }
 
+    public function testVariadicArray()
+    {
+        $stmts = self::$_parser->parse('<?php
+        function f(int ...$a_list) {
+            return array_map(function (int $a) {
+                return $a + 1;
+            }, $a_list);
+        }
+
+        f(1);
+        f(1, 2);
+        f(1, 2, 3);
+        ');
+
+        $file_checker = new \Psalm\Checker\FileChecker('somefile.php', $stmts);
+        $context = new Context('somefile.php');
+        $file_checker->check(true, true, $context);
+    }
+
     public function testArgumentUnpacking()
     {
         $stmts = self::$_parser->parse('<?php