Update codeActionProvider type to support CodeActionOptions

Summary:
LSP now has the ability to tell the client upon intialization which code actions we support: see [ServerCapabilities.codeActionProvider](https://microsoft.github.io/language-server-protocol/specifications/specification-current/#initialize) and [CodeActionOptions](https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_codeAction). This diff updates `lsp.ml` to reflect this.

Relevant LSP commits:
- [Adding CodeActionOptions to the `codeActionProvider` server capability](microsoft/language-server-protocol@9ae6daa)
- [renaming `CodeActionOptions.providedCodeActionKinds` to `CodeActionOptions.codeActionKinds`](microsoft/language-server-protocol@7aed39b)

Reviewed By: nmote

Differential Revision: D20007191

fbshipit-source-id: e5c7e5b51710eaf8c9f9b51d4d09ba2a1cec4e39

src/hack_forked/utils/lsp/lsp.ml

@@ -444,7 +444,7 @@ module Initialize = struct
     (* ie. document outline *)
     workspaceSymbolProvider: bool;
     (* ie. find-symbol-in-project *)
-    codeActionProvider: bool;
+    codeActionProvider: codeActionOptions;
     codeLensProvider: codeLensOptions option;
     documentFormattingProvider: bool;
     documentRangeFormattingProvider: bool;
@@ -468,6 +468,10 @@ module Initialize = struct
     sighelp_triggerCharacters: string list; (* wire "triggerCharacters" *)
   }
 
+  and codeActionOptions =
+    | CodeActionBool of bool
+    | CodeActionOptions of { codeActionKinds: CodeActionKind.t list }
+
   and codeLensOptions = { codelens_resolveProvider: bool (* wire "resolveProvider" *) }
 
   and documentOnTypeFormattingOptions = {

src/hack_forked/utils/lsp/lsp.mli

@@ -281,7 +281,7 @@ module Initialize : sig
     documentHighlightProvider: bool;
     documentSymbolProvider: bool;
     workspaceSymbolProvider: bool;
-    codeActionProvider: bool;
+    codeActionProvider: codeActionOptions;
     codeLensProvider: codeLensOptions option;
     documentFormattingProvider: bool;
     documentRangeFormattingProvider: bool;
@@ -301,6 +301,10 @@ module Initialize : sig
 
   and signatureHelpOptions = { sighelp_triggerCharacters: string list }
 
+  and codeActionOptions =
+    | CodeActionBool of bool
+    | CodeActionOptions of { codeActionKinds: CodeActionKind.t list }
+
   and codeLensOptions = { codelens_resolveProvider: bool }
 
   and documentOnTypeFormattingOptions = {

src/hack_forked/utils/lsp/lsp_fmt.ml

@@ -969,7 +969,19 @@ let print_initialize (r : Initialize.result) : json =
               ("documentHighlightProvider", Some (JSON_Bool cap.documentHighlightProvider));
               ("documentSymbolProvider", Some (JSON_Bool cap.documentSymbolProvider));
               ("workspaceSymbolProvider", Some (JSON_Bool cap.workspaceSymbolProvider));
-              ("codeActionProvider", Some (JSON_Bool cap.codeActionProvider));
+              ( "codeActionProvider",
+                Some
+                  (match cap.codeActionProvider with
+                  | CodeActionBool b -> JSON_Bool b
+                  | CodeActionOptions { codeActionKinds } ->
+                    JSON_Object
+                      [
+                        ( "codeActionKinds",
+                          JSON_Array
+                            (List.map
+                               ~f:(fun k -> JSON_String (CodeActionKind.string_of_kind k))
+                               codeActionKinds) );
+                      ]) );
               ( "codeLensProvider",
                 Base.Option.map cap.codeLensProvider ~f:(fun codelens ->
                     JSON_Object [("resolveProvider", JSON_Bool codelens.codelens_resolveProvider)])

src/lsp/flowLsp.ml

@@ -472,7 +472,7 @@ let send_lsp_to_server (cenv : connected_env) (metadata : LspProt.metadata) (mes
 (************************************************************************)
 
 let do_initialize flowconfig : Initialize.result =
-  let code_action_provider = FlowConfig.autofix_exports flowconfig in
+  let code_action_provider = Initialize.CodeActionBool (FlowConfig.autofix_exports flowconfig) in
   Initialize.
     {
       server_capabilities =