Use a property AST node for mixed types

Reviewed By: avikchaudhuri

Differential Revision: D3979312

fbshipit-source-id: 1669566d2fb73c5cfa8f6fe44ade30649be6012e

Author: samwgoldman

src/parser/estree_translator.ml

@@ -918,6 +918,7 @@ end with type t = Impl.t) = struct
   and _type (loc, t) = Type.(
     match t with
     | Any -> any_type loc
+    | Mixed -> mixed_type loc
     | Void -> void_type loc
     | Null -> null_type loc
     | Number -> number_type loc
@@ -940,6 +941,8 @@ end with type t = Impl.t) = struct
 
   and any_type loc = node "AnyTypeAnnotation" loc [||]
 
+  and mixed_type loc = node "MixedTypeAnnotation" loc [||]
+
   and void_type loc = node "VoidTypeAnnotation" loc [||]
 
   and null_type loc = node "NullTypeAnnotation" loc [||]

src/parser/lexer_flow.mll

@@ -135,6 +135,7 @@ module Token = struct
     | T_JSX_TEXT of (Loc.t * string * string) (* loc, value, raw *)
     (* Type primitives *)
     | T_ANY_TYPE
+    | T_MIXED_TYPE
     | T_BOOLEAN_TYPE
     | T_NUMBER_TYPE
     | T_NUMBER_SINGLETON_TYPE of number_type * float
@@ -275,6 +276,7 @@ module Token = struct
     | T_JSX_TEXT _ -> "T_JSX_TEXT"
     (* Type primitives *)
     | T_ANY_TYPE -> "T_ANY_TYPE"
+    | T_MIXED_TYPE -> "T_MIXED_TYPE"
     | T_BOOLEAN_TYPE -> "T_BOOLEAN_TYPE"
     | T_NUMBER_TYPE -> "T_NUMBER_TYPE"
     | T_NUMBER_SINGLETON_TYPE _ -> "T_NUMBER_SINGLETON_TYPE"
@@ -725,6 +727,7 @@ end
       "static",  T_STATIC;
       "typeof",  T_TYPEOF;
       "any",     T_ANY_TYPE;
+      "mixed",   T_MIXED_TYPE;
       "bool",    T_BOOLEAN_TYPE;
       "boolean", T_BOOLEAN_TYPE;
       "true",    T_TRUE;

src/parser/parser_flow.ml

@@ -259,6 +259,7 @@ end = struct
 
     and primitive = function
       | T_ANY_TYPE     -> Some Type.Any
+      | T_MIXED_TYPE   -> Some Type.Mixed
       | T_BOOLEAN_TYPE -> Some Type.Boolean
       | T_NUMBER_TYPE  -> Some Type.Number
       | T_STRING_TYPE  -> Some Type.String

src/parser/spider_monkey_ast.ml

@@ -151,6 +151,7 @@ and Type : sig
    * should never be declared nullable, but that check can happen later *)
   and t' =
     | Any
+    | Mixed
     | Void
     | Null
     | Number

src/parser/test/hardcoded_tests.js

@@ -4234,7 +4234,7 @@ module.exports = {
               'params': [
                 {
                   'name.name': 'x',
-                  'typeAnnotation.type': 'GenericTypeAnnotation',
+                  'typeAnnotation.type': 'MixedTypeAnnotation',
                 }
               ],
               'returnType.type': 'BooleanTypeAnnotation'
@@ -4276,14 +4276,7 @@ module.exports = {
               'typeAnnotation':{
                 'type':'TypeAnnotation',
                 'typeAnnotation':{
-                  'type':'GenericTypeAnnotation',
-                  'id':{
-                    'type':'Identifier',
-                    'name':'mixed',
-                    'typeAnnotation':null,
-                    'optional':false
-                  },
-                  'typeParameters':null
+                  'type':'MixedTypeAnnotation',
                 }
               },
               'optional':false
@@ -4342,14 +4335,7 @@ module.exports = {
                     'typeAnnotation':{
                       'type':'TypeAnnotation',
                       'typeAnnotation':{
-                        'type':'GenericTypeAnnotation',
-                        'id':{
-                          'type':'Identifier',
-                          'name':'mixed',
-                          'typeAnnotation':null,
-                          'optional':false
-                        },
-                        'typeParameters':null
+                        'type':'MixedTypeAnnotation',
                       }
                     },
                     'optional':false

src/typing/type_annotation.ml

@@ -53,6 +53,8 @@ let rec convert cx tparams_map = Ast.Type.(function
 
 | loc, Any -> AnyT.at loc
 
+| loc, Mixed -> MixedT.at loc
+
 | loc, Void -> VoidT.at loc
 
 | loc, Null -> NullT.at loc
@@ -165,12 +167,6 @@ let rec convert cx tparams_map = Ast.Type.(function
 
   begin match name with
 
-  (* TODO Type.Mixed *)
-  | "mixed" ->
-    check_type_param_arity cx loc typeParameters 0 (fun () ->
-      MixedT.at loc
-    )
-
   (* Array<T> *)
   | "Array" ->
     check_type_param_arity cx loc typeParameters 1 (fun () ->