Investigate heuristics in jump to location.

There are a number of heuristics when getting a loc item from a text position.
These heuristics are related to the behaviours of the JSX ppx and internal compiler behaviours that leak into the position of elements.

Author: cristianoc

analysis/src/Cli.ml

@@ -72,18 +72,22 @@ let main () =
       ~pos:(int_of_string line, int_of_string col)
       ~currentFile
   | [_; "definition"; path; line; col] ->
-    Commands.definition ~path ~line:(int_of_string line)
-      ~col:(int_of_string col)
+    Commands.definition ~path
+      ~pos:(int_of_string line, int_of_string col)
+      ~debug:false
   | [_; "typeDefinition"; path; line; col] ->
-    Commands.typeDefinition ~path ~line:(int_of_string line)
-      ~col:(int_of_string col)
+    Commands.typeDefinition ~path
+      ~pos:(int_of_string line, int_of_string col)
+      ~debug:false
   | [_; "documentSymbol"; path] -> DocumentSymbol.command ~path
   | [_; "hover"; path; line; col; currentFile] ->
-    Commands.hover ~path ~line:(int_of_string line) ~col:(int_of_string col)
+    Commands.hover ~path
+      ~pos:(int_of_string line, int_of_string col)
       ~currentFile ~debug:false
   | [_; "codeAction"; path; line; col; currentFile] ->
-    Commands.codeAction ~path ~line:(int_of_string line)
-      ~col:(int_of_string col) ~currentFile
+    Commands.codeAction ~path
+      ~pos:(int_of_string line, int_of_string col)
+      ~currentFile ~debug:false
   | _ :: "reanalyze" :: _ ->
     let len = Array.length Sys.argv in
     for i = 1 to len - 2 do
@@ -92,11 +96,13 @@ let main () =
     Sys.argv.(len - 1) <- "";
     Reanalyze.cli ()
   | [_; "references"; path; line; col] ->
-    Commands.references ~path ~line:(int_of_string line)
-      ~col:(int_of_string col)
+    Commands.references ~path
+      ~pos:(int_of_string line, int_of_string col)
+      ~debug:false
   | [_; "rename"; path; line; col; newName] ->
-    Commands.rename ~path ~line:(int_of_string line) ~col:(int_of_string col)
-      ~newName
+    Commands.rename ~path
+      ~pos:(int_of_string line, int_of_string col)
+      ~newName ~debug:false
   | [_; "semanticTokens"; currentFile] ->
     SemanticTokens.semanticTokens ~currentFile
   | [_; "createInterface"; path; cmiFile] ->

analysis/src/Commands.ml

@@ -28,19 +28,18 @@ let completion ~debug ~path ~pos ~currentFile =
     |> List.map Protocol.stringifyCompletionItem
     |> Protocol.array)
 
-let hover ~path ~line ~col ~currentFile ~debug =
+let hover ~path ~pos ~currentFile ~debug =
   let result =
     match Cmt.fullFromPath ~path with
     | None -> Protocol.null
     | Some full -> (
-      match References.getLocItem ~full ~line ~col with
+      match References.getLocItem ~full ~pos ~debug with
       | None -> (
         if debug then
           Printf.printf
             "Nothing at that position. Now trying to use completion.\n";
         let completions =
-          getCompletions ~debug ~path ~pos:(line, col) ~currentFile
-            ~forHover:true
+          getCompletions ~debug ~path ~pos ~currentFile ~forHover:true
         in
         match completions with
         | {kind = Label typString; docstring} :: _ ->
@@ -81,16 +80,16 @@ let hover ~path ~line ~col ~currentFile ~debug =
   in
   print_endline result
 
-let codeAction ~path ~line ~col ~currentFile =
-  Xform.extractCodeActions ~path ~pos:(line, col) ~currentFile
+let codeAction ~path ~pos ~currentFile ~debug =
+  Xform.extractCodeActions ~path ~pos ~currentFile ~debug
   |> CodeActions.stringifyCodeActions |> print_endline
 
-let definition ~path ~line ~col =
+let definition ~path ~pos ~debug =
   let locationOpt =
     match Cmt.fullFromPath ~path with
     | None -> None
     | Some full -> (
-      match References.getLocItem ~full ~line ~col with
+      match References.getLocItem ~full ~pos ~debug with
       | None -> None
       | Some locItem -> (
         match References.definitionForLocItem ~full locItem with
@@ -123,12 +122,12 @@ let definition ~path ~line ~col =
     | None -> Protocol.null
     | Some location -> location |> Protocol.stringifyLocation)
 
-let typeDefinition ~path ~line ~col =
+let typeDefinition ~path ~pos ~debug =
   let maybeLocation =
     match Cmt.fullFromPath ~path with
     | None -> None
     | Some full -> (
-      match References.getLocItem ~full ~line ~col with
+      match References.getLocItem ~full ~pos ~debug with
       | None -> None
       | Some locItem -> (
         match References.typeDefinitionForLocItem ~full locItem with
@@ -143,12 +142,12 @@ let typeDefinition ~path ~line ~col =
     | None -> Protocol.null
     | Some location -> location |> Protocol.stringifyLocation)
 
-let references ~path ~line ~col =
+let references ~path ~pos ~debug =
   let allLocs =
     match Cmt.fullFromPath ~path with
     | None -> []
     | Some full -> (
-      match References.getLocItem ~full ~line ~col with
+      match References.getLocItem ~full ~pos ~debug with
       | None -> []
       | Some locItem ->
         let allReferences = References.allReferencesForLocItem ~full locItem in
@@ -169,12 +168,12 @@ let references ~path ~line ~col =
     (if allLocs = [] then Protocol.null
     else "[\n" ^ (allLocs |> String.concat ",\n") ^ "\n]")
 
-let rename ~path ~line ~col ~newName =
+let rename ~path ~pos ~newName ~debug =
   let result =
     match Cmt.fullFromPath ~path with
     | None -> Protocol.null
     | Some full -> (
-      match References.getLocItem ~full ~line ~col with
+      match References.getLocItem ~full ~pos ~debug with
       | None -> Protocol.null
       | Some locItem ->
         let allReferences = References.allReferencesForLocItem ~full locItem in
@@ -305,24 +304,24 @@ let test ~path =
             print_endline
               ("Definition " ^ path ^ " " ^ string_of_int line ^ ":"
              ^ string_of_int col);
-            definition ~path ~line ~col
+            definition ~path ~pos:(line, col) ~debug:true
           | "typ" ->
             print_endline
               ("TypeDefinition " ^ path ^ " " ^ string_of_int line ^ ":"
              ^ string_of_int col);
-            typeDefinition ~path ~line ~col
+            typeDefinition ~path ~pos:(line, col) ~debug:true
           | "hov" ->
             print_endline
               ("Hover " ^ path ^ " " ^ string_of_int line ^ ":"
              ^ string_of_int col);
             let currentFile = createCurrentFile () in
-            hover ~path ~line ~col ~currentFile ~debug:true;
+            hover ~path ~pos:(line, col) ~currentFile ~debug:true;
             Sys.remove currentFile
           | "ref" ->
             print_endline
               ("References " ^ path ^ " " ^ string_of_int line ^ ":"
              ^ string_of_int col);
-            references ~path ~line ~col
+            references ~path ~pos:(line, col) ~debug:true
           | "doc" ->
             print_endline ("DocumentSymbol " ^ path);
             DocumentSymbol.command ~path
@@ -333,7 +332,7 @@ let test ~path =
                 ("Rename " ^ path ^ " " ^ string_of_int line ^ ":"
                ^ string_of_int col ^ " " ^ newName)
             in
-            rename ~path ~line ~col ~newName
+            rename ~path ~pos:(line, col) ~newName ~debug:true
           | "com" ->
             print_endline
               ("Complete " ^ path ^ " " ^ string_of_int line ^ ":"
@@ -362,6 +361,7 @@ let test ~path =
              ^ string_of_int col);
             let codeActions =
               Xform.extractCodeActions ~path ~pos:(line, col) ~currentFile:path
+                ~debug:true
             in
             codeActions
             |> List.iter (fun {Protocol.title; edit = {documentChanges}} ->

analysis/src/References.ml

@@ -1,6 +1,7 @@
 open SharedTypes
 
 let debugReferences = ref true
+
 let maybeLog m = if !debugReferences then Log.log ("[ref] " ^ m)
 
 let checkPos (line, char)
@@ -16,10 +17,11 @@ let checkPos (line, char)
 let locItemsForPos ~extra pos =
   extra.locItems |> List.filter (fun {loc; locType = _} -> checkPos pos loc)
 
-let lineColToCmtLoc ~line ~col = (line + 1, col)
+let lineColToCmtLoc ~pos:(line, col) = (line + 1, col)
 
-let getLocItem ~full ~line ~col =
-  let pos = lineColToCmtLoc ~line ~col in
+let getLocItem ~full ~pos ~debug =
+  let log n msg = if debug then Printf.printf "getLocItem #%d: %s\n" n msg in
+  let pos = lineColToCmtLoc ~pos in
   let locItems = locItemsForPos ~extra:full.extra pos in
   if !Log.verbose then
     print_endline
@@ -28,30 +30,33 @@ let getLocItem ~full ~line ~col =
   match locItems with
   | _ :: _ :: _ :: ({locType = Typed ("makeProps", _, _)} as li) :: _
     when full.file.uri |> Uri2.isInterface ->
-    (* heuristic for makeProps in interface files *)
+    log 1 "heuristic for makeProps in interface files";
     Some li
   | [
    {locType = Typed ("fragment", _, _)};
    {locType = Typed ("createElement", _, _)};
   ] ->
-    (* heuristic for </Comp> within a fragment *)
+    log 2 "heuristic for </Comp> within a fragment";
     None
   | [
    {locType = Constant _};
    ({locType = Typed ("createDOMElementVariadic", _, _)} as li2);
   ] ->
-    (* heuristic for <div> *)
+    log 3 "heuristic for <div>";
     Some li2
   | {locType = Typed ("makeProps", _, _)}
     :: ({locType = Typed ("make", _, _)} as li2) :: _ ->
-    (* heuristic for </Comp> within fragments: take make as makeProps does not work
-       the type is not greatl but jump to definition works *)
+    log 4
+      "heuristic for </Comp> within fragments: take make as makeProps does not \
+       work\n\
+       the type is not great but jump to definition works";
     Some li2
   | [({locType = Typed (_, _, LocalReference _)} as li1); li3]
     when li1.loc = li3.loc ->
-    (* JSX and compiler combined:
-       ~x becomes Props#x
-       heuristic for: [Props, x], give loc of `x` *)
+    log 5
+      "heuristic for JSX and compiler combined:\n\
+       ~x becomes Props#x\n\
+       heuristic for: [Props, x], give loc of `x`";
     Some li3
   | [
    ({locType = Typed (_, _, LocalReference _)} as li1);
@@ -61,28 +66,33 @@ let getLocItem ~full ~line ~col =
   ]
   (* For older compiler 9.0 or earlier *)
     when li1.loc = li2.loc && li2.loc = li3.loc ->
-    (* JSX and compiler combined:
-       ~x becomes Js_OO.unsafe_downgrade(Props)#x
-       heuristic for: [Props, unsafe_downgrade, x], give loc of `x` *)
+    log 6
+      "heuristic for JSX and compiler combined:\n\
+       ~x becomes Js_OO.unsafe_downgrade(Props)#x\n\
+       heuristic for: [Props, unsafe_downgrade, x], give loc of `x`";
     Some li3
   | [
    {locType = Typed (_, _, LocalReference (_, Value))};
    ({locType = Typed (_, _, Definition (_, Value))} as li2);
   ] ->
-    (* JSX on type-annotated labeled (~arg:t):
-       (~arg:t) becomes Props#arg
-       Props has the location range of arg:t
-       arg has the location range of arg
-       heuristic for: [Props, arg], give loc of `arg` *)
+    log 7
+      "heuristic for JSX on type-annotated labeled (~arg:t):\n\
+       (~arg:t) becomes Props#arg\n\
+       Props has the location range of arg:t\n\
+       arg has the location range of arg\n\
+       heuristic for: [Props, arg], give loc of `arg`";
     Some li2
   | [li1; li2; li3] when li1.loc = li2.loc && li2.loc = li3.loc ->
-    (* JSX with at most one child
-       heuristic for: [makeProps, make, createElement], give the loc of `make` *)
+    log 8
+      "heuristic for JSX with at most one child\n\
+       heuristic for: [makeProps, make, createElement], give the loc of `make` ";
     Some li2
   | [li1; li2; li3; li4]
     when li1.loc = li2.loc && li2.loc = li3.loc && li3.loc = li4.loc ->
-    (* JSX variadic, e.g. <C> {x} {y} </C>
-       heuristic for: [makeProps  , React.null, make, createElementVariadic], give the loc of `make` *)
+    log 9
+      "heuristic for JSX variadic, e.g. <C> {x} {y} </C>\n\
+       heuristic for: [makeProps  , React.null, make, createElementVariadic], \
+       give the loc of `make`";
     Some li3
   | {locType = Typed (_, {desc = Tconstr (path, _, _)}, _)} :: li :: _
     when Utils.isUncurriedInternal path ->

analysis/src/Xform.ml

@@ -223,16 +223,14 @@ module AddTypeAnnotation = struct
     in
     {Ast_iterator.default_iterator with structure_item}
 
-  let xform ~path ~pos ~full ~structure ~codeActions =
-    let line, col = pos in
-
+  let xform ~path ~pos ~full ~structure ~codeActions ~debug =
     let result = ref None in
     let iterator = mkIterator ~pos ~result in
     iterator.structure iterator structure;
     match !result with
     | None -> ()
     | Some annotation -> (
-      match References.getLocItem ~full ~line ~col with
+      match References.getLocItem ~full ~pos ~debug with
       | None -> ()
       | Some locItem -> (
         match locItem.locType with
@@ -297,14 +295,14 @@ let parse ~filename =
   in
   (structure, printExpr, printStructureItem)
 
-let extractCodeActions ~path ~pos ~currentFile =
+let extractCodeActions ~path ~pos ~currentFile ~debug =
   match Cmt.fullFromPath ~path with
   | Some full when Filename.check_suffix currentFile ".res" ->
     let structure, printExpr, printStructureItem =
       parse ~filename:currentFile
     in
     let codeActions = ref [] in
-    AddTypeAnnotation.xform ~path ~pos ~full ~structure ~codeActions;
+    AddTypeAnnotation.xform ~path ~pos ~full ~structure ~codeActions ~debug;
     IfThenElse.xform ~pos ~codeActions ~printExpr ~path structure;
     AddBracesToFn.xform ~pos ~codeActions ~path ~printStructureItem structure;
     !codeActions

analysis/tests/src/expected/Div.res.txt

@@ -1,4 +1,5 @@
 Hover src/Div.res 0:10
+getLocItem #3: heuristic for <div>
 {"contents": "```rescript\n(\n  string,\n  ~props: ReactDOMRe.domProps=?,\n  array<React.element>,\n) => React.element\n```"}
 
 Complete src/Div.res 3:17

analysis/tests/src/expected/Fragment.res.txt

@@ -1,7 +1,10 @@
 Hover src/Fragment.res 6:19
+getLocItem #4: heuristic for </Comp> within fragments: take make as makeProps does not work
+the type is not great but jump to definition works
 {"contents": "```rescript\nReact.component<{\"children\": React.element}>\n```\n\n```rescript\ntype component<'props> = componentLike<'props, element>\n```"}
 
 Hover src/Fragment.res 9:56
+getLocItem #2: heuristic for </Comp> within a fragment
 Nothing at that position. Now trying to use completion.
 posCursor:[9:56] posNoWhite:[9:55] Found expr:[9:10->9:67]
 Pexp_construct :::[9:13->9:67] [9:13->9:67]

analysis/tests/src/expected/Hover.res.txt

@@ -20,9 +20,17 @@ Hover src/Hover.res 33:4
 {"contents": "```rescript\nunit => int\n```\n\nDoc comment for functionWithTypeAnnotation"}
 
 Hover src/Hover.res 37:13
+getLocItem #5: SX and compiler combined:
+~x becomes Props#x
+heuristic for: [Props, x], give loc of `x`
 {"contents": "```rescript\nstring\n```"}
 
 Hover src/Hover.res 41:13
+getLocItem #7: JSX on type-annotated labeled (~arg:t):
+(~arg:t) becomes Props#arg
+Props has the location range of arg:t
+arg has the location range of arg
+heuristic for: [Props, arg], give loc of `arg`
 {"contents": "```rescript\nstring\n```"}
 
 Hover src/Hover.res 44:10
@@ -47,9 +55,13 @@ Hover src/Hover.res 75:7
 {"contents": "```rescript\nmodule A = {\n  let x: int\n}\n```"}
 
 Hover src/Hover.res 85:10
+getLocItem #9: JSX variadic, e.g. <C> {x} {y} </C>
+heuristic for: [makeProps  , React.null, make, createElementVariadic], give the loc of `make`
 {"contents": "```rescript\nReact.component<{\"children\": React.element}>\n```\n\n```rescript\ntype component<'props> = componentLike<'props, element>\n```"}
 
 Hover src/Hover.res 88:10
+getLocItem #9: JSX variadic, e.g. <C> {x} {y} </C>
+heuristic for: [makeProps  , React.null, make, createElementVariadic], give the loc of `make`
 {"contents": "```rescript\nReact.component<{\"children\": React.element}>\n```\n\n```rescript\ntype component<'props> = componentLike<'props, element>\n```"}
 
 Hover src/Hover.res 93:25

analysis/tests/src/expected/Jsx.res.txt

@@ -1,4 +1,6 @@
 Definition src/Jsx.res 5:9
+getLocItem #4: heuristic for </Comp> within fragments: take make as makeProps does not work
+the type is not great but jump to definition works
 {"uri": "Jsx.res", "range": {"start": {"line": 2, "character": 6}, "end": {"line": 2, "character": 10}}}
 
 Complete src/Jsx.res 8:15
@@ -196,6 +198,8 @@ Completable: Cjsx([M], k, [prop, k])
   }]
 
 Definition src/Jsx.res 58:11
+getLocItem #4: heuristic for </Comp> within fragments: take make as makeProps does not work
+the type is not great but jump to definition works
 {"uri": "Component.res", "range": {"start": {"line": 1, "character": 4}, "end": {"line": 1, "character": 8}}}
 
 Complete src/Jsx.res 68:10