Complete lowercase JSX labels from the domProps type

CHANGELOG.md

@@ -15,6 +15,7 @@
 - Better error recovery when analysis fails. https://github.com/rescript-lang/rescript-vscode/pull/880
 - Expand type aliases in hovers. https://github.com/rescript-lang/rescript-vscode/pull/881
 - Include fields when completing a braced expr that's an ID, where it the path likely starts with a module. https://github.com/rescript-lang/rescript-vscode/pull/882
+- Complete domProps for lowercase JSX components from `ReactDOM.domProps` if possible. https://github.com/rescript-lang/rescript-vscode/pull/883
 
 ## 1.32.0
 

analysis/src/CompletionBackEnd.ml

@@ -548,6 +548,24 @@ let getCompletionsForPath ~debug ~package ~opens ~full ~pos ~exact ~scope
       findAllCompletions ~env ~prefix ~exact ~namesUsed ~completionContext
     | None -> [])
 
+let rec digToRecordFieldsForCompletion ~debug ~package ~opens ~full ~pos ~env
+    ~scope path =
+  match
+    path
+    |> getCompletionsForPath ~debug ~completionContext:Type ~exact:true ~package
+         ~opens ~full ~pos ~env ~scope
+  with
+  | {kind = Type {kind = Abstract (Some (p, _))}} :: _ ->
+    (* This case happens when what we're looking for is a type alias.
+       This is the case in newer rescript-react versions where
+       ReactDOM.domProps is an alias for JsxEvent.t. *)
+    let pathRev = p |> Utils.expandPath in
+    pathRev |> List.rev
+    |> digToRecordFieldsForCompletion ~debug ~package ~opens ~full ~pos ~env
+         ~scope
+  | {kind = Type {kind = Record fields}} :: _ -> Some fields
+  | _ -> None
+
 let mkItem ~name ~kind ~detail ~deprecated ~docstring =
   let docContent =
     (match deprecated with
@@ -571,7 +589,7 @@ let mkItem ~name ~kind ~detail ~deprecated ~docstring =
       detail;
       documentation =
         (if docContent = "" then None
-        else Some {kind = "markdown"; value = docContent});
+         else Some {kind = "markdown"; value = docContent});
       sortText = None;
       insertText = None;
       insertTextFormat = None;
@@ -1043,25 +1061,16 @@ and getCompletionsForContextPath ~debug ~full ~opens ~rawOpens ~pos ~env ~exact
     in
     let targetLabel =
       if lowercaseComponent then
-        let rec digToTypeForCompletion path =
-          match
-            path
-            |> getCompletionsForPath ~debug ~completionContext:Type ~exact:true
-                 ~package ~opens ~full ~pos ~env ~scope
-          with
-          | {kind = Type {kind = Abstract (Some (p, _))}} :: _ ->
-            (* This case happens when what we're looking for is a type alias.
-               This is the case in newer rescript-react versions where
-               ReactDOM.domProps is an alias for JsxEvent.t. *)
-            let pathRev = p |> Utils.expandPath in
-            pathRev |> List.rev |> digToTypeForCompletion
-          | {kind = Type {kind = Record fields}} :: _ -> (
-            match fields |> List.find_opt (fun f -> f.fname.txt = propName) with
-            | None -> None
-            | Some f -> Some (f.fname.txt, f.typ, env))
-          | _ -> None
-        in
-        ["ReactDOM"; "domProps"] |> digToTypeForCompletion
+        match
+          ["ReactDOM"; "domProps"]
+          |> digToRecordFieldsForCompletion ~debug ~package ~opens ~full ~pos
+               ~env ~scope
+        with
+        | None -> None
+        | Some fields -> (
+          match fields |> List.find_opt (fun f -> f.fname.txt = propName) with
+          | None -> None
+          | Some f -> Some (f.fname.txt, f.typ, env))
       else
         CompletionJsx.getJsxLabels ~componentPath:pathToComponent
           ~findTypeOfValue ~package
@@ -1541,20 +1550,49 @@ let rec processCompletable ~debug ~full ~scope ~env ~pos ~forHover completable =
     contextPath
     |> getCompletionsForContextPath ~debug ~full ~opens ~rawOpens ~pos ~env
          ~exact:forHover ~scope
-  | Cjsx ([id], prefix, identsSeen) when String.uncapitalize_ascii id = id ->
+  | Cjsx ([id], prefix, identsSeen) when String.uncapitalize_ascii id = id -> (
     (* Lowercase JSX tag means builtin *)
     let mkLabel (name, typString) =
       Completion.create name ~kind:(Label typString) ~env
     in
     let keyLabels =
       if Utils.startsWith "key" prefix then [mkLabel ("key", "string")] else []
     in
-    (CompletionJsx.domLabels
-    |> List.filter (fun (name, _t) ->
-           Utils.startsWith name prefix
-           && (forHover || not (List.mem name identsSeen)))
-    |> List.map mkLabel)
-    @ keyLabels
+    (* We always try to look up completion from the actual domProps type first.
+       This works in JSXv4. For JSXv3, we have a backup hardcoded list of dom
+       labels we can use for completion. *)
+    let fromDomProps =
+      match
+        ["ReactDOM"; "domProps"]
+        |> digToRecordFieldsForCompletion ~debug ~package ~opens ~full ~pos ~env
+             ~scope
+      with
+      | None -> None
+      | Some fields ->
+        Some
+          (fields
+          |> List.filter_map (fun (f : field) ->
+                 if
+                   Utils.startsWith f.fname.txt prefix
+                   && (forHover || not (List.mem f.fname.txt identsSeen))
+                 then
+                   Some
+                     ( f.fname.txt,
+                       Shared.typeToString (Utils.unwrapIfOption f.typ) )
+                 else None)
+          |> List.map mkLabel)
+    in
+    match fromDomProps with
+    | Some domProps -> domProps
+    | None ->
+      if debug then
+        Printf.printf "Could not find ReactDOM.domProps to complete from.\n";
+      (CompletionJsx.domLabels
+      |> List.filter (fun (name, _t) ->
+             Utils.startsWith name prefix
+             && (forHover || not (List.mem name identsSeen)))
+      |> List.map mkLabel)
+      @ keyLabels)
   | Cjsx (componentPath, prefix, identsSeen) ->
     let labels =
       CompletionJsx.getJsxLabels ~componentPath ~findTypeOfValue ~package

analysis/tests/src/CompletionJsx.res

@@ -48,3 +48,6 @@ module CompWithoutJsxPpx = {
 
 // <SomeComponent someProp=>
 //                         ^com
+
+// <h1 hidd
+//         ^com

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

@@ -1684,6 +1684,8 @@ Completable: Cjsx([div], name, [name])
 Raw opens: 2 Shadow.B.place holder ... Shadow.A.place holder
 Package opens Pervasives.JsxModules.place holder
 Resolved opens 3 pervasives Completion.res Completion.res
+Path ReactDOM.domProps
+Path Pervasives.JsxDOM.domProps
 {"contents": {"kind": "markdown", "value": "```rescript\nstring\n```"}}
 
 Hover src/Completion.res 349:17

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

@@ -492,3 +492,19 @@ Path SomeComponent.make
     "insertTextFormat": 2
   }]
 
+Complete src/CompletionJsx.res 51:11
+posCursor:[51:11] posNoWhite:[51:10] Found expr:[51:4->51:11]
+JSX <h1:[51:4->51:6] hidd[51:7->51:11]=...[51:7->51:11]> _children:None
+Completable: Cjsx([h1], hidd, [hidd])
+Package opens Pervasives.JsxModules.place holder
+Resolved opens 1 pervasives
+Path ReactDOM.domProps
+Path Pervasives.JsxDOM.domProps
+[{
+    "label": "hidden",
+    "kind": 4,
+    "tags": [],
+    "detail": "bool",
+    "documentation": null
+  }]
+

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

@@ -8,6 +8,8 @@ JSX <div:[3:4->3:7] dangerous[3:8->3:17]=...[3:8->3:17]> _children:None
 Completable: Cjsx([div], dangerous, [dangerous])
 Package opens Pervasives.JsxModules.place holder
 Resolved opens 1 pervasives
+Path ReactDOM.domProps
+Path Pervasives.JsxDOM.domProps
 [{
     "label": "dangerouslySetInnerHTML",
     "kind": 4,