hphp/hack/test/typecheck/typehole/T90668594.php

   1 <?hh
   2
   3 class :xhp {
   4   attribute string attr;
   5
   6   public function __construct(
   7     public darray<string,mixed> $attributes,
   8     varray<mixed> $_,
   9     string $_,
  10     int $_,
  11   ): void {}
  12
  13   public function getAttribute(string $attr, mixed $default = null): mixed {
  14     $this->attributes['attr'] = 42;
  15
  16     return $this->attributes[$attr];
  17   }
  18 }
  19
  20 function takes_string(string $_): void {}
  21
  22 <<__EntryPoint>>
  23 function oops(): void {
  24   $xhp = <xhp attr="hi" />;
  25   // Type refinement causes attribute to become an int
  26   if ($xhp->:attr is nonnull) {
  27     // The typechecker thinks the type of $xhp->attr is string
  28     takes_string($xhp->:attr); // Fatals
  29   }
  30 }