Add support for prop completion for JSX V4

rescript-lang/rescript#5406

Author: cristianoc

Diff for: CHANGELOG.md

@@ -12,6 +12,10 @@
 
 ## master
 
+#### :rocket: New Feature
+
+- Add support for prop completion for JSX V4
+
 ## v1.6.0
 
 #### :rocket: New Feature

Diff for: analysis/src/CompletionBackEnd.ml

@@ -1427,16 +1427,39 @@ let processCompletable ~debug ~package ~scope ~env ~pos ~forHover
   | Cjsx (componentPath, prefix, identsSeen) ->
     let labels =
       match componentPath @ ["make"] |> findTypeOfValue with
-      | Some (typ, _env) ->
-        let rec getFields (texp : Types.type_expr) =
+      | Some (typ, make_env) ->
+        let rec getFieldsV3 (texp : Types.type_expr) =
           match texp.desc with
           | Tfield (name, _, t1, t2) ->
-            let fields = t2 |> getFields in
+            let fields = t2 |> getFieldsV3 in
             if name = "children" then fields else (name, t1) :: fields
-          | Tlink te | Tsubst te | Tpoly (te, []) -> te |> getFields
+          | Tlink te | Tsubst te | Tpoly (te, []) -> te |> getFieldsV3
           | Tvar None -> []
           | _ -> []
         in
+        let getFieldsV4 ~path ~typeArgs =
+          match References.digConstructor ~env:make_env ~package path with
+          | Some
+              ( _env,
+                {
+                  item =
+                    {
+                      decl =
+                        {
+                          type_kind = Type_record (labelDecls, _repr);
+                          type_params = typeParams;
+                        };
+                    };
+                } ) ->
+            labelDecls
+            |> List.map (fun (ld : Types.label_declaration) ->
+                   let name = Ident.name ld.ld_id in
+                   let t =
+                     ld.ld_type |> instantiateType ~typeParams ~typeArgs
+                   in
+                   (name, t))
+          | _ -> []
+        in
         let rec getLabels (t : Types.type_expr) =
           match t.desc with
           | Tlink t1 | Tsubst t1 | Tpoly (t1, []) -> getLabels t1
@@ -1449,9 +1472,14 @@ let processCompletable ~debug ~package ~scope ~env ~pos ~forHover
                 },
                 _,
                 _ ) ->
-            getFields tObj
+            (* JSX V3 *)
+            getFieldsV3 tObj
+          | Tarrow (Nolabel, {desc = Tconstr (path, typeArgs, _)}, _, _)
+            when Path.last path = "props" ->
+            (* JSX V4 *)
+            getFieldsV4 ~path ~typeArgs
           | Tconstr
-              ( path,
+              ( clPath,
                 [
                   {
                     desc =
@@ -1461,8 +1489,14 @@ let processCompletable ~debug ~package ~scope ~env ~pos ~forHover
                   _;
                 ],
                 _ )
-            when Path.name path = "React.componentLike" ->
-            getFields tObj
+            when Path.name clPath = "React.componentLike" ->
+            (* JSX V3 external or interface *)
+            getFieldsV3 tObj
+          | Tconstr (clPath, [{desc = Tconstr (path, typeArgs, _)}; _], _)
+            when Path.name clPath = "React.componentLike"
+                 && Path.last path = "props" ->
+            (* JSX V4 external or interface *)
+            getFieldsV4 ~path ~typeArgs
           | _ -> []
         in
         typ |> getLabels
@@ -1480,6 +1514,7 @@ let processCompletable ~debug ~package ~scope ~env ~pos ~forHover
       (labels
       |> List.filter (fun (name, _t) ->
              Utils.startsWith name prefix
+             && name <> "key"
              && (forHover || not (List.mem name identsSeen)))
       |> List.map mkLabel)
       @ keyLabels

Diff for: analysis/tests/src/JsxV4.res

@@ -0,0 +1,12 @@
+@@jsxConfig({version: 4})
+
+module M4 = {
+  @react.component
+  let make = (~first, ~fun="", ~second="") => React.string(first ++ fun ++ second)
+}
+
+let _ = <M4 first="abc" />
+//       ^def
+
+// <M4 first="abc" f
+//                  ^com

Diff for: analysis/tests/src/expected/JsxV4.res.txt

@@ -0,0 +1,18 @@
+Definition src/JsxV4.res 7:9
+getLocItem #9: heuristic for JSX variadic, e.g. <C> {x} {y} </C>
+heuristic for: [React.null, makeProps, make, createElementVariadic], give the loc of `make`
+n1:() n2:makeProps n3:make n4:createElement
+{"uri": "JsxV4.res", "range": {"start": {"line": 4, "character": 6}, "end": {"line": 4, "character": 10}}}
+
+Complete src/JsxV4.res 10:20
+posCursor:[10:20] posNoWhite:[10:19] Found expr:[10:4->10:20]
+JSX <M4:[10:4->10:6] first[10:7->10:12]=...[10:13->10:18] f[10:19->10:20]=...[10:19->10:20]> _children:None
+Completable: Cjsx([M4], f, [first, f])
+[{
+    "label": "fun",
+    "kind": 4,
+    "tags": [],
+    "detail": "option<string>",
+    "documentation": null
+  }]
+