Extract shape type to alias

Summary:
Add a new refactoring for creating a type alias from a shape hint.

This is distinct from the existing refactoring which creates a type alias from a shape *expression*.

https://pxl.cl/2SC6H

## Choice made

Despite the two refactors being different, I combined them in the same file because:
- this reduces the number of visitors and thereby save traversal cost
- this saves some boilerplate without (imo) too much readability impairment

Reviewed By: nt591

Differential Revision: D47188912

fbshipit-source-id: 1f7d8a6c659c5178263bc9b43b725ba8fb52c57c

Author: mheiber

hphp/hack/src/server/server_code_actions_services/extract_shape_type.ml

@@ -1,11 +1,21 @@
 open Hh_prelude
 
-type candidate = {
-  tast_env: Tast_env.t;
-  (* the function or class containing the shape expression *)
-  container_pos: Pos.t;
-  shape_ty: Typing_defs.locl_ty;
-}
+type candidate =
+  | Of_expr of {
+      tast_env: Tast_env.t;
+      (* the function or class containing the shape expression *)
+      expr_container_pos: Pos.t;
+      shape_ty: Typing_defs.locl_ty;
+    }
+  | Of_hint of {
+      hint_container_pos: Pos.t;
+      hint_pos: Pos.t;
+    }
+
+(** We use distinct titles so we can tell the refactors apart in analytics *)
+let title_of_candidate = function
+  | Of_expr _ -> "Extract shape type"
+  | Of_hint _ -> "Extract shape type to alias"
 
 type state =
   | Searching of (Pos.t * candidate) option
@@ -54,6 +64,13 @@ let find_candidate ~(selection : Pos.t) ~entry ctx : candidate option =
         ) else
           Searching None
 
+      method! on_type_hint_ env hint_ =
+        match Option.both hint_ !container_pos with
+        | Some ((hint_pos, Aast_defs.Hshape _), hint_container_pos)
+          when Pos.contains selection hint_pos ->
+          Searching (Some (hint_pos, Of_hint { hint_container_pos; hint_pos }))
+        | _ -> super#on_type_hint_ env hint_
+
       method! on_fun_def env fd =
         let pos = Aast_defs.(fd.fd_fun.f_span) in
         if Pos.contains pos selection then (
@@ -67,9 +84,12 @@ let find_candidate ~(selection : Pos.t) ~entry ctx : candidate option =
         if Pos.contains selection expr_pos then
           let ty_ = Typing_defs_core.get_node ty in
           match (ty_, !container_pos) with
-          | (Typing_defs_core.Tshape _, Some container_pos) ->
+          | (Typing_defs_core.Tshape _, Some expr_container_pos) ->
             Searching
-              (Some (expr_pos, { tast_env = env; container_pos; shape_ty = ty }))
+              (Some
+                 ( expr_pos,
+                   Of_expr { tast_env = env; expr_container_pos; shape_ty = ty }
+                 ))
           | _ -> Selected_non_shape_type expr_pos
         else
           super#on_expr env expr
@@ -81,24 +101,52 @@ let find_candidate ~(selection : Pos.t) ~entry ctx : candidate option =
   | Selected_non_shape_type _ ->
     None
 
-let edit_of_candidate ~path { shape_ty; container_pos; tast_env } :
-    Lsp.WorkspaceEdit.t =
-  let edit =
-    let pos = Pos.shrink_to_start container_pos in
-    let range =
-      Lsp_helpers.hack_pos_to_lsp_range ~equal:Relative_path.equal pos
-    in
-    let tenv = Tast_env.tast_env_as_typing_env tast_env in
-    let ty_text = Typing_print.full_strip_ns tenv shape_ty in
-    let text = Printf.sprintf "type T${0:placeholder_} = %s;\n\n" ty_text in
-    Lsp.TextEdit.{ range; newText = text }
+let snippet_for_decl_of : string -> string =
+  Printf.sprintf "type T${0:placeholder_} = %s;\n\n"
+
+let snippet_for_use = "T${0:placeholder_}"
+
+let range_of_container_pos container_pos : Lsp.range =
+  let pos = Pos.shrink_to_start container_pos in
+  Lsp_helpers.hack_pos_to_lsp_range ~equal:Relative_path.equal pos
+
+let edit_of_candidate source_text ~path candidate : Lsp.WorkspaceEdit.t =
+  let sub_of_pos = Full_fidelity_source_text.sub_of_pos source_text in
+  let edits =
+    match candidate with
+    | Of_expr { shape_ty; expr_container_pos; tast_env } ->
+      let range = range_of_container_pos expr_container_pos in
+      let text =
+        let ty_text =
+          let tenv = Tast_env.tast_env_as_typing_env tast_env in
+          Typing_print.full_strip_ns tenv shape_ty
+        in
+        snippet_for_decl_of ty_text
+      in
+      [Lsp.TextEdit.{ range; newText = text }]
+    | Of_hint { hint_container_pos; hint_pos } ->
+      let decl_edit =
+        let range = range_of_container_pos hint_container_pos in
+        let text =
+          let ty_text = sub_of_pos hint_pos in
+          snippet_for_decl_of ty_text
+        in
+        Lsp.TextEdit.{ range; newText = text }
+      in
+      let use_edit =
+        let range =
+          Lsp_helpers.hack_pos_to_lsp_range ~equal:Relative_path.equal hint_pos
+        in
+        Lsp.TextEdit.{ range; newText = snippet_for_use }
+      in
+      [decl_edit; use_edit]
   in
-  let changes = SMap.singleton (Relative_path.to_absolute path) [edit] in
+  let changes = SMap.singleton (Relative_path.to_absolute path) edits in
   Lsp.WorkspaceEdit.{ changes }
 
-let to_refactor ~path candidate =
-  let edit = lazy (edit_of_candidate ~path candidate) in
-  Code_action_types.Refactor.{ title = "Extract shape type"; edit }
+let to_refactor source_text ~path candidate =
+  let edit = lazy (edit_of_candidate source_text ~path candidate) in
+  Code_action_types.Refactor.{ title = title_of_candidate candidate; edit }
 
 let find ~entry ~(range : Lsp.range) ctx =
   let source_text = Ast_provider.compute_source_text ~entry in
@@ -108,5 +156,5 @@ let find ~entry ~(range : Lsp.range) ctx =
   let path = entry.Provider_context.path in
   let selection = Lsp_helpers.lsp_range_to_pos ~line_to_offset path range in
   find_candidate ~selection ~entry ctx
-  |> Option.map ~f:(to_refactor ~path)
+  |> Option.map ~f:(to_refactor source_text ~path)
   |> Option.to_list

hphp/hack/test/ide_code_actions/extract_shape_type_to_alias/HH_FLAGS

@@ -0,0 +1,22 @@
+(rule
+ (alias ide_code_actions_extract_shape_type_to_alias)
+ (deps
+  %{exe:../../../src/hh_single_type_check.exe}
+  %{project_root}/hack/test/verify.py
+  %{project_root}/hack/test/review.sh
+  (glob_files %{project_root}/hack/test/ide_code_actions/extract_shape_type_to_alias/HH_FLAGS)
+  (glob_files %{project_root}/hack/test/ide_code_actions/extract_shape_type_to_alias/*.php)
+  (glob_files %{project_root}/hack/test/ide_code_actions/extract_shape_type_to_alias/*.exp))
+ (action
+  (run
+   %{project_root}/hack/test/verify.py
+   %{project_root}/hack/test/ide_code_actions/extract_shape_type_to_alias
+   --program
+   %{exe:../../../src/hh_single_type_check.exe}
+   --flags
+   --ide-code-actions "Extract shape type")))
+
+(alias
+ (name runtest)
+ (deps
+  (alias ide_code_actions_extract_shape_type_to_alias)))

hphp/hack/test/ide_code_actions/extract_shape_type_to_alias/dune

@@ -0,0 +1,3 @@
+<?hh
+
+function foo(/*range-start*/shape('a' => int)/*range-end*/ $_): void {}

hphp/hack/test/ide_code_actions/extract_shape_type_to_alias/extract_shape_type_to_alias_1.php

@@ -0,0 +1,34 @@
+Code actions available:
+------------------------------------------
+Extract shape type to alias (CodeActionKind: refactor) SELECTED
+
+JSON for selected code action:
+------------------------------------------
+{
+  "diagnostics":[],
+  "edit":{
+    "changes":{
+      "FILE.php":[
+        {
+          "newText":"type T${0:placeholder_} = shape('a' => int);\n\n",
+          "range":{"end":{"character":0,"line":2},"start":{"character":0,"line":2}}
+        },
+        {
+          "newText":"T${0:placeholder_}",
+          "range":{"end":{"character":45,"line":2},"start":{"character":28,"line":2}}
+        }
+      ]
+    }
+  },
+  "kind":"refactor",
+  "title":"Extract shape type to alias"
+}
+
+Applied edit for code action:
+------------------------------------------
+<?hh
+
+type T${0:placeholder_} = shape('a' => int);
+
+function foo(/*range-start*/T${0:placeholder_}/*range-end*/ $_): void {}
+

hphp/hack/test/ide_code_actions/extract_shape_type_to_alias/extract_shape_type_to_alias_1.php.exp

@@ -0,0 +1,5 @@
+<?hh
+
+class A {
+  public function foo(/*range-start*/shape('a' => int, ...)/*range-end*/ $_): void {}
+}

hphp/hack/test/ide_code_actions/extract_shape_type_to_alias/extract_shape_type_to_alias_2.php

@@ -0,0 +1,36 @@
+Code actions available:
+------------------------------------------
+Extract shape type to alias (CodeActionKind: refactor) SELECTED
+
+JSON for selected code action:
+------------------------------------------
+{
+  "diagnostics":[],
+  "edit":{
+    "changes":{
+      "FILE.php":[
+        {
+          "newText":"type T${0:placeholder_} = shape('a' => int, ...);\n\n",
+          "range":{"end":{"character":0,"line":2},"start":{"character":0,"line":2}}
+        },
+        {
+          "newText":"T${0:placeholder_}",
+          "range":{"end":{"character":59,"line":3},"start":{"character":37,"line":3}}
+        }
+      ]
+    }
+  },
+  "kind":"refactor",
+  "title":"Extract shape type to alias"
+}
+
+Applied edit for code action:
+------------------------------------------
+<?hh
+
+type T${0:placeholder_} = shape('a' => int, ...);
+
+class A {
+  public function foo(/*range-start*/T${0:placeholder_}/*range-end*/ $_): void {}
+}
+

hphp/hack/test/ide_code_actions/extract_shape_type_to_alias/extract_shape_type_to_alias_2.php.exp

@@ -0,0 +1,8 @@
+<?hh
+
+type TShape = shape('a' => int);
+
+class A {
+  // we don't provide the refactoring unless a shape hint literal is selected
+  public function foo(/*range-start*/TShape/*range-end*/ $_): void {}
+}

hphp/hack/test/ide_code_actions/extract_shape_type_to_alias/extract_shape_type_to_alias_3.php

@@ -0,0 +1 @@
+No commands or actions found

hphp/hack/test/ide_code_actions/extract_shape_type_to_alias/extract_shape_type_to_alias_3.php.exp

@@ -0,0 +1,5 @@
+<?hh
+
+class A {
+  public function foo(shape('a' => /*range-start*/shape('inner' => int)/*range-end*/) $_): void {}
+}