hphp/hack/src/typing/tast_check/foreach_collection_reactivity_check.ml

   1 (*
   2  * Copyright (c) 2018, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under the MIT license found in the
   6  * LICENSE file in the "hack" directory of this source tree.
   7  *
   8  *)
   9
  10 open Hh_prelude
  11 open Aast
  12 open Typing_defs
  13 module Env = Tast_env
  14 module MakeType = Typing_make_type
  15 module SN = Naming_special_names
  16
  17 let rxTraversableType =
  18   MakeType.class_type
  19     Reason.none
  20     SN.Rx.cTraversable
  21     [MakeType.mixed Reason.Rnone]
  22
  23 let rxAsyncIteratorType =
  24   MakeType.class_type
  25     Reason.none
  26     SN.Rx.cAsyncIterator
  27     [MakeType.mixed Reason.Rnone]
  28
  29 let check_foreach_collection env p ty =
  30   (* do nothing if unsafe_rx is set *)
  31   if TypecheckerOptions.unsafe_rx (Env.get_tcopt env) then
  32     ()
  33   else
  34     match Env.env_reactivity env with
  35     | r when not (any_reactive r) -> ()
  36     | _ ->
  37       let rec check ty =
  38         let (env, ty) = Env.expand_type env ty in
  39         match get_node ty with
  40         | Tunion l -> List.for_all l ~f:check
  41         | Tdynamic ->
  42           (* If it's a dynamic, we have no way of knowing whether or not it's
  43               valid. Let it fail at runtime *)
  44           true
  45         | _ ->
  46           (* collection type should be subtype or conditioned to Rx\Traversable *)
  47           if
  48             not
  49               ( Env.can_subtype env ty rxTraversableType
  50               || Env.can_subtype env ty rxAsyncIteratorType
  51               || Env.condition_type_matches
  52                    ~is_self:false
  53                    env
  54                    ty
  55                    rxTraversableType
  56               || Env.condition_type_matches
  57                    ~is_self:false
  58                    env
  59                    ty
  60                    rxAsyncIteratorType )
  61           then (
  62             Errors.invalid_traversable_in_rx p;
  63             false
  64           ) else
  65             true
  66       in
  67       ignore (check ty)
  68
  69 let handler =
  70   object
  71     inherit Tast_visitor.handler_base
  72
  73     method! at_stmt env x =
  74       match snd x with
  75       | Foreach (((p, ty), _), _, _) -> check_foreach_collection env p ty
  76       | _ -> ()
  77   end