hphp/hack/test/typecheck/not_trivial_strict_eq.php

   1 <?hh
   2 /**
   3  * Copyright (c) 2014, Facebook, Inc.
   4  * All rights reserved.
   5  *
   6  * This source code is licensed under the BSD-style license found in the
   7  * LICENSE file in the "hack" directory of this source tree. An additional grant
   8  * of patent rights can be found in the PATENTS file in the same directory.
   9  *
  10  */
  11
  12 function f() {}
  13
  14 function getArr(): array<int> { return array(); }
  15
  16 function g(): void {
  17   $a = getArr();
  18   $b = array();
  19   $idx = f();
  20
  21   // not entirely sure why, but this if statement is needed to trigger an error
  22   // in a naive implementation of the trivial strict equality check
  23   if (true) {
  24   }
  25
  26   /* This is not a trivial strict equality check [4118]: $idx will be inferred
  27    * to be an int inside the if block, but right now it is still TAny. This
  28    * test verifies that we are doing the trivial strict equality test at the
  29    * right point */
  30   if ($idx !== false) {
  31     $b[] = $a[$idx];
  32   }
  33 }
  34
  35 function h(?int $a, ?string $b): bool {
  36   // Not a trivial comparison since both $a and $b can be null
  37   return $a === $b;
  38 }