[flow][get-def] Special case get-def for Pick with string literals in…

… the second targ

Summary: Changelog: [ide] For `Pick` utility type with string literals in the second type argument, go-to-definition on the string literal will jump to corresponding prop's location

Reviewed By: gkz

Differential Revision: D60403582

fbshipit-source-id: 48bbfc4371a7d163fcd8efdca51b0e07d5488212

src/services/get_def/getDef_js.ml

@@ -33,14 +33,11 @@ let extract_member_def ~loc_of_aloc ~cx ~file_sig ~typed_ast_opt ~force_instance
   | Some def_locs -> Ok (Nel.map loc_of_aloc def_locs, Some name)
   | None -> Error (Printf.sprintf "failed to find member %s in members map" name)
 
-let rec process_request ~loc_of_aloc ~cx ~is_legit_require ~ast ~typed_ast_opt ~file_sig :
-    (ALoc.t, ALoc.t * Type.t) Get_def_request.t -> (Loc.t Nel.t * string option, string) result =
+let rec process_request ~loc_of_aloc ~cx ~is_legit_require ~ast ~typed_ast_opt ~file_sig ~scope_info
+    : (ALoc.t, ALoc.t * Type.t) Get_def_request.t -> (Loc.t Nel.t * string option, string) result =
   function
   | Get_def_request.Identifier { name; loc = (aloc, type_) } ->
     let loc = loc_of_aloc aloc in
-    let scope_info =
-      Scope_builder.program ~enable_enums:(Context.enable_enums cx) ~with_types:true ast
-    in
     let all_uses = Scope_api.With_Loc.all_uses scope_info in
     let matching_uses = Loc_collections.LocSet.filter (fun use -> Loc.contains use loc) all_uses in
     (match Loc_collections.LocSet.elements matching_uses with
@@ -50,7 +47,15 @@ let rec process_request ~loc_of_aloc ~cx ~is_legit_require ~ast ~typed_ast_opt ~
       Ok (def_loc, Some name)
     | [] ->
       let req = Get_def_request.Type { annot = (aloc, type_); name = Some name } in
-      process_request ~loc_of_aloc ~cx ~is_legit_require ~ast ~typed_ast_opt ~file_sig req
+      process_request
+        ~loc_of_aloc
+        ~cx
+        ~is_legit_require
+        ~ast
+        ~typed_ast_opt
+        ~file_sig
+        ~scope_info
+        req
     | _ :: _ :: _ -> Error "Scope builder found multiple matching identifiers")
   | Get_def_request.(Member { prop_name = name; object_type = (_loc, t); force_instance }) ->
     extract_member_def ~loc_of_aloc ~cx ~file_sig ~typed_ast_opt ~force_instance t name
@@ -70,7 +75,7 @@ let rec process_request ~loc_of_aloc ~cx ~is_legit_require ~ast ~typed_ast_opt ~
         Member { prop_name = name; object_type = (loc, props_object); force_instance = false }
       )
     in
-    process_request ~loc_of_aloc ~cx ~is_legit_require ~ast ~typed_ast_opt ~file_sig req
+    process_request ~loc_of_aloc ~cx ~is_legit_require ~ast ~typed_ast_opt ~file_sig ~scope_info req
 
 module Depth = struct
   let limit = 100
@@ -121,11 +126,15 @@ end
 
 let get_def ~loc_of_aloc ~cx ~file_sig ~ast ~available_ast ~purpose requested_loc =
   let require_loc_map = File_sig.require_loc_map file_sig in
+  let scope_info =
+    Scope_builder.program ~enable_enums:(Context.enable_enums cx) ~with_types:true ast
+  in
+  let is_local_use aloc = Scope_api.With_Loc.is_local_use scope_info (loc_of_aloc aloc) in
   let is_legit_require source_aloc =
     let source_loc = loc_of_aloc source_aloc in
     SMap.exists (fun _ locs -> List.exists (fun loc -> loc = source_loc) locs) require_loc_map
   in
-  let rec loop ~depth req_loc loop_name =
+  let rec loop ~scope_info ~depth req_loc loop_name =
     match Depth.add req_loc depth with
     | Error error ->
       let trace_of_locs locs =
@@ -148,7 +157,9 @@ let get_def ~loc_of_aloc ~cx ~file_sig ~ast ~available_ast ~purpose requested_lo
     | Ok Depth.NoResult ->
       let open Get_def_process_location in
       let result =
-        match process_location cx ~is_legit_require ~available_ast ~purpose req_loc with
+        match
+          process_location cx ~is_local_use ~is_legit_require ~available_ast ~purpose req_loc
+        with
         | OwnDef (aloc, name) -> Def (LocSet.singleton (loc_of_aloc aloc), Some name)
         | Request request -> begin
           match
@@ -159,6 +170,7 @@ let get_def ~loc_of_aloc ~cx ~file_sig ~ast ~available_ast ~purpose requested_lo
               ~ast
               ~typed_ast_opt:(Typed_ast_utils.typed_ast_of_available_ast available_ast)
               ~file_sig
+              ~scope_info
               request
           with
           | Ok (res_locs, name) ->
@@ -172,7 +184,7 @@ let get_def ~loc_of_aloc ~cx ~file_sig ~ast ~available_ast ~purpose requested_lo
                    if Loc.equal req_loc res_loc || Loc.(res_loc.source <> requested_loc.source) then
                      Def (LocSet.singleton res_loc, name)
                    else
-                     match loop ~depth res_loc name with
+                     match loop ~scope_info ~depth res_loc name with
                      | Bad_loc _ -> Def (LocSet.singleton res_loc, name)
                      | Def_error msg -> Partial (LocSet.singleton res_loc, name, msg)
                      | (Def _ | Partial _) as res -> res
@@ -198,4 +210,4 @@ let get_def ~loc_of_aloc ~cx ~file_sig ~ast ~available_ast ~purpose requested_lo
       Depth.cache_result req_loc result depth;
       result
   in
-  loop ~depth:(Depth.empty ()) requested_loc None
+  loop ~depth:(Depth.empty ()) ~scope_info requested_loc None

src/services/get_def/get_def_process_location.ml

@@ -85,7 +85,7 @@ let annot_of_jsx_name =
   | MemberExpression (_, MemberExpression.{ property = (annot, _); _ }) ->
     annot
 
-class virtual ['T] searcher _cx ~is_legit_require ~covers_target ~purpose =
+class virtual ['T] searcher _cx ~is_local_use ~is_legit_require ~covers_target ~purpose =
   object (this)
     inherit [ALoc.t, 'T, ALoc.t, 'T] enclosing_node_mapper as super
 
@@ -238,6 +238,40 @@ class virtual ['T] searcher _cx ~is_legit_require ~covers_target ~purpose =
       end;
       super#member loc expr
 
+    method! generic_type expr =
+      let open Ast.Type.Generic in
+      let { id; targs; comments = _ } = expr in
+      begin
+        match (id, targs) with
+        | ( Identifier.Unqualified (pick_annot, { Ast.Identifier.name = "Pick"; comments = _ }),
+            Some (_, { Ast.Type.TypeArgs.arguments = [(obj_annot, _); keys]; _ })
+          )
+          when not (is_local_use (this#loc_of_annot pick_annot)) ->
+          let request annot prop_name =
+            if this#annot_covers_target annot then
+              let obj_annot =
+                (this#loc_of_annot obj_annot, this#type_from_enclosing_node obj_annot)
+              in
+              let result =
+                Get_def_request.(
+                  Member { prop_name; object_type = obj_annot; force_instance = false }
+                )
+              in
+              this#request result
+          in
+          (match keys with
+          | (annot, Ast.Type.StringLiteral { Ast.StringLiteral.value; _ }) -> request annot value
+          | (_, Ast.Type.Union { Ast.Type.Union.types = (t1, t2, ts); _ }) ->
+            Base.List.iter (t1 :: t2 :: ts) ~f:(function
+                | (annot, Ast.Type.StringLiteral { Ast.StringLiteral.value; _ }) ->
+                  request annot value
+                | _ -> ()
+                )
+          | _ -> ())
+        | _ -> ()
+      end;
+      super#generic_type expr
+
     method! indexed_access_type expr =
       let open Ast.Type.IndexedAccess in
       let { _object; index; comments = _ } = expr in
@@ -591,9 +625,9 @@ class virtual ['T] searcher _cx ~is_legit_require ~covers_target ~purpose =
         pn
   end
 
-class typed_ast_searcher _cx ~typed_ast:_ ~is_legit_require ~covers_target ~purpose =
+class typed_ast_searcher _cx ~typed_ast:_ ~is_local_use ~is_legit_require ~covers_target ~purpose =
   object
-    inherit [ALoc.t * Type.t] searcher _cx ~is_legit_require ~covers_target ~purpose
+    inherit [ALoc.t * Type.t] searcher _cx ~is_local_use ~is_legit_require ~covers_target ~purpose
 
     method private loc_of_annot (loc, _) = loc
 
@@ -653,9 +687,9 @@ let find_remote_name_def_loc_in_node loc node =
 
 exception Internal_error_exn of internal_error
 
-class on_demand_searcher cx ~is_legit_require ~covers_target ~purpose =
+class on_demand_searcher cx ~is_local_use ~is_legit_require ~covers_target ~purpose =
   object (this)
-    inherit [ALoc.t] searcher cx ~is_legit_require ~covers_target ~purpose
+    inherit [ALoc.t] searcher cx ~is_local_use ~is_legit_require ~covers_target ~purpose
 
     method on_type_annot x = x
 
@@ -713,13 +747,17 @@ let search ~searcher ast =
   | exception Internal_error_exn err -> InternalError err
   | _ -> searcher#found_loc
 
-let process_location cx ~available_ast ~is_legit_require ~purpose loc =
+let process_location cx ~available_ast ~is_local_use ~is_legit_require ~purpose loc =
   match available_ast with
   | Typed_ast_utils.Typed_ast typed_ast ->
     let covers_target test_loc = Reason.in_range loc (ALoc.to_loc_exn test_loc) in
-    let searcher = new typed_ast_searcher () ~typed_ast ~is_legit_require ~covers_target ~purpose in
+    let searcher =
+      new typed_ast_searcher () ~typed_ast ~is_local_use ~is_legit_require ~covers_target ~purpose
+    in
     search ~searcher typed_ast
   | Typed_ast_utils.ALoc_ast aloc_ast ->
     let covers_target test_loc = Reason.in_range loc (ALoc.to_loc_exn test_loc) in
-    let searcher = new on_demand_searcher cx ~is_legit_require ~covers_target ~purpose in
+    let searcher =
+      new on_demand_searcher cx ~is_local_use ~is_legit_require ~covers_target ~purpose
+    in
     search ~searcher aloc_ast

src/services/get_def/get_def_process_location.mli

@@ -25,6 +25,7 @@ type 'loc result =
  * `ALoc.t * Type.t` through an inferred constraint. *)
 class virtual ['T] searcher :
   'c
+  -> is_local_use:(ALoc.t -> bool)
   -> is_legit_require:(ALoc.t -> bool)
   -> covers_target:(ALoc.t -> bool)
   -> purpose:Get_def_types.Purpose.t
@@ -62,6 +63,7 @@ val process_type_request : Context.t -> Type.t -> (ALoc.t, string) Stdlib.result
 val process_location :
   Context.t ->
   available_ast:Typed_ast_utils.available_ast ->
+  is_local_use:(ALoc.t -> bool) ->
   is_legit_require:(ALoc.t -> bool) ->
   purpose:Get_def_types.Purpose.t ->
   Loc.t ->

tests/get_def2/get_def2.exp

@@ -208,6 +208,33 @@ constructor.js:14:6
 Flags:
 constructor.js:10:7,10:9
 
+pick.js:8:24
+Flags:
+
+pick.js:12:23
+Flags:
+pick.js:3:13,3:15
+
+pick.js:14:23
+Flags:
+pick.js:3:26,3:28
+
+pick.js:17:23
+Flags:
+pick.js:16:6,16:8
+
+pick.js:20:23
+Flags:
+pick.js:3:13,3:15
+
+pick.js:22:32
+Flags:
+pick.js:3:26,3:28
+
+pick.js:24:29
+Flags:
+pick.js:3:26,3:28
+
 utilities.js:7:10
 Flags:
 utilities.js:3:20,3:22

tests/get_def2/pick.js

@@ -0,0 +1,25 @@
+// @flow
+
+type Obj = {foo: string, bar: number};
+
+function locally_defined_pick() {
+  type Pick<A, B> = A;
+
+  type T = Pick<Obj, 'foo'>; // no result for locally defined pick
+//                     ^
+}
+
+type T1 = Pick<Obj, 'foo'>; // jump to foo prop
+//                    ^
+type T2 = Pick<Obj, 'bar'>; // jump to bar prop
+//                    ^
+type Foo = 'foo';
+type T3 = Pick<Obj, Foo>; // jump to type Foo, instead of jumping to foo prop
+//                    ^
+
+type T4 = Pick<Obj, 'foo' | 'bar'>;  // jump to foo prop
+//                    ^
+type T5 = Pick<Obj, 'foo' | 'bar'>;  // jump to bar prop
+//                             ^
+type T6 = Pick<Obj, Foo | 'bar'>;  // jump to bar prop
+//                          ^

tests/get_def2/test.sh

@@ -16,4 +16,5 @@ queries_in_file get-def "declare.js"
 queries_in_file get-def "private_name.js"
 queries_in_file get-def "static.js"
 queries_in_file get-def "constructor.js"
+queries_in_file get-def "pick.js"
 queries_in_file get-def "utilities.js"