[autofix][insert-type] lift shadow properties to real properties

Summary: This reuses another piece of annotate exports to make valid type annotations when a field is cast but never initialized.

Reviewed By: panagosg7

Differential Revision: D16114811

fbshipit-source-id: 8756e140bf826432c73c670e071bd34f927d2279

src/services/type_info/insert_type.ml

@@ -195,22 +195,22 @@ let fail_when_ty_size_exceeds size_limit ty =
 
 
 (* Generate an equivalent Flow_ast.Type *)
-let serialize ?(imports_react=false) ty =
-  (new Utils.patch_up_react_mapper ~imports_react ())#on_t () ty
+let serialize ?(imports_react=false) loc ty =
+  (new Utils.patch_up_react_mapper ~imports_react ())#on_t loc ty
   |> Ty_utils.simplify_type ~simplify_empty:true
   |> Ty_serializer.type_
   |> function
   | Ok ast -> Utils.patch_up_type_ast ast
   | Error msg -> raise (unexpected (FailedToSerialize {ty; error_message=msg}))
 
-let remove_ambiguous_types ~ambiguity_strategy ty =
+let remove_ambiguous_types ~ambiguity_strategy ty loc =
   match ambiguity_strategy with
   | Fail ->
     begin try fail_on_ambiguity ty with
       | FoundAmbiguousType ->
         raise @@ expected @@ MulipleTypesPossibleAtPoint {
-          specialized=specialize_temporary_types ty |> serialize;
-          generalized=generalize_temporary_types ty |> serialize;
+          specialized=specialize_temporary_types ty |> serialize loc;
+          generalized=generalize_temporary_types ty |> serialize loc;
         }
     end
   | Temporary  -> allow_temporary_arr_and_obj_types ty
@@ -242,8 +242,8 @@ class mapper ?(size_limit=30) ~ambiguity_strategy
       | Utils.Fatal error -> raise @@ expected @@
           FailedToValidateType{error; error_message=Utils.serialize_validation_error error}
     end;
-    let ty = remove_ambiguous_types ~ambiguity_strategy ty in
-    (location, serialize ~imports_react:true ty)
+    let ty = remove_ambiguous_types ~ambiguity_strategy ty location in
+    (location, serialize ~imports_react:true location ty)
 
   method private synth_type_annotation_hint loc =
     Flow_ast.Type.Available (this#synth_type loc)

src/services/type_info/insert_type_utils.ml

@@ -25,6 +25,9 @@ let serialize_validation_error = function
   | Empty_SomeUnknownUpper u ->
     Utils_js.spf "Empty_SomeUnknownUpper (use: %s)" u
 
+let warn_shadow_prop ?(strip_root=None) name loc =
+    Hh_logger.warn "ShadowProp %s at %s" name (Reason.string_of_loc ?strip_root loc)
+
 exception Fatal of validation_error
 (* Raise an validation_error if there isn't a user facing type that is equivalent to the Ty *)
 class type_validator_visitor = object(_)
@@ -121,9 +124,9 @@ let is_react_loc loc =
   | _ -> false
 
 (* Apply stylistic changes to react types *)
-class ['A] patch_up_react_mapper ?(imports_react=false) () = object (this)
-  inherit ['A] Ty.endo_ty as super
-  method! on_t a t =
+class patch_up_react_mapper ?(imports_react=false) () = object (this)
+  inherit [_] Ty.endo_ty as super
+  method! on_t loc t =
     match t with
 
     (* If 'react' is not imported, then we treat the symbol as Remote, so that
@@ -139,12 +142,24 @@ class ['A] patch_up_react_mapper ?(imports_react=false) () = object (this)
         def_loc;
         _} as symbol, kind, args_opt)
       when is_react_loc def_loc ->
-      let args_opt = Flow_ast_mapper.map_opt (ListUtils.ident_map (this#on_t a)) args_opt in
+      let args_opt = Flow_ast_mapper.map_opt (ListUtils.ident_map (this#on_t loc)) args_opt in
       let symbol = if imports_react
         then { symbol with Ty.name = "React." ^ name }
         else { symbol with Ty.provenance = Ty.Remote { Ty.imported_as = None } } in
       Ty.Generic (symbol, kind, args_opt)
-    | _ -> super#on_t a t
+    | _ -> super#on_t loc t
+
+    method! on_prop loc prop =
+      let prop = match prop with
+        | Ty.NamedProp (name, named_prop)
+          when Reason.is_internal_name name ->
+          warn_shadow_prop name loc;
+          (* Shadow props appear as regular props *)
+          let name = String.sub name 1 (String.length name - 1) in
+          Ty.NamedProp (name, named_prop)
+        | prop -> prop
+      in
+      super#on_prop loc prop
 end
 
 (* Returns true if the location given a zero width location. *)

tests/autofix-empty-object/.flowconfig

@@ -0,0 +1,12 @@
+[ignore]
+
+[include]
+
+[libs]
+
+[lints]
+
+[options]
+experimental.well_formed_exports=true
+
+[strict]

tests/autofix-empty-object/.testconfig

@@ -0,0 +1 @@
+shell: test.sh

tests/autofix-empty-object/a.js

@@ -0,0 +1,3 @@
+// @flow
+
+module.exports = {};

tests/autofix-empty-object/autofix-empty-object.exp

@@ -0,0 +1,65 @@
+> insert-type a.js 3 18 3 20
+cat a.js
+// @flow
+
+module.exports = ({}: {});
+> insert-type b.js 3 23 3 25
+cat b.js
+// @flow
+
+module.exports = { f: ({}: {}) };
+> insert-type c.js 3 18 3 20
+cat c.js
+// @flow
+
+const obj = { f: ({}: {}) };
+
+obj.f = { x: 1 };
+obj.f = { x: "a" };
+
+module.exports = obj;
+> insert-type d.js 3 13 3 16
+cat d.js
+// @flow
+
+const obj: {f: {x: number}, g: {x: string}} = { };
+
+obj.f = { x: 1 };
+obj["g"] = { x: "a" };
+
+module.exports = obj;
+> insert-type e.js 3 13 3 15
+cat e.js
+// @flow
+
+const obj: {a: number} = {};
+declare function foo(x: { a: number }): void;
+foo(obj);
+module.exports = obj;
+> insert-type f.js 3 13 3 15
+cat f.js
+// @flow
+
+const obj: {f: number} = {};
+(obj.f: number);
+module.exports = obj;
+> insert-type g.js 5 13 5 15
+cat g.js
+// @flow
+
+declare function foo<X: { a: 1 }>(x: X): void;
+
+const obj: {a: 1} = {};
+foo(obj);
+module.exports = obj;
+> insert-type h.js 4 5 4 8
+cat h.js
+// @flow
+
+
+let obj: {x: number} = {};
+obj.x = 5;
+
+module.exports = obj;
+> flow status
+No errors!

tests/autofix-empty-object/b.js

@@ -0,0 +1,3 @@
+// @flow
+
+module.exports = { f: {} };

tests/autofix-empty-object/c.js

@@ -0,0 +1,8 @@
+// @flow
+
+const obj = { f: {} };
+
+obj.f = { x: 1 };
+obj.f = { x: "a" };
+
+module.exports = obj;

tests/autofix-empty-object/d.js

@@ -0,0 +1,8 @@
+// @flow
+
+const obj = { };
+
+obj.f = { x: 1 };
+obj["g"] = { x: "a" };
+
+module.exports = obj;

tests/autofix-empty-object/e.js

@@ -0,0 +1,6 @@
+// @flow
+
+const obj = {};
+declare function foo(x: { a: number }): void;
+foo(obj);
+module.exports = obj;

tests/autofix-empty-object/f.js

@@ -0,0 +1,5 @@
+// @flow
+
+const obj = {};
+(obj.f: number);
+module.exports = obj;

tests/autofix-empty-object/g.js

@@ -0,0 +1,7 @@
+// @flow
+
+declare function foo<X: { a: 1 }>(x: X): void;
+
+const obj = {};
+foo(obj);
+module.exports = obj;

tests/autofix-empty-object/h.js

@@ -0,0 +1,7 @@
+// @flow
+
+
+let obj = {};
+obj.x = 5;
+
+module.exports = obj;

tests/autofix-empty-object/test.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+update_in_place(){
+  local FILE=$1;
+  echo "> insert-type" "$@"
+  assert_ok "$FLOW" autofix insert-type --in-place "$@"
+  assert_ok "$FLOW" force-recheck "$FILE"
+  echo "cat $FILE"
+  cat "$FILE"
+}
+
+update_in_place a.js 3 18 3 20
+update_in_place b.js 3 23 3 25
+update_in_place c.js 3 18 3 20
+update_in_place d.js 3 13 3 16
+update_in_place e.js 3 13 3 15
+update_in_place f.js 3 13 3 15
+update_in_place g.js 5 13 5 15
+update_in_place h.js 4 5 4 8
+
+echo "> flow status"
+assert_ok "$FLOW" status --strip-root