handle options with annotations

Author: zth

analysis/src/CompletionBackEnd.ml

@@ -630,6 +630,19 @@ let rec getCompletionsForContextPath ~full ~opens ~rawOpens ~allFiles ~pos ~env
           (Completion.Value
              (Ctype.newconstr (Path.Pident (Ident.create "array")) []));
     ]
+  | CPOption cp -> (
+    match
+      cp
+      |> getCompletionsForContextPath ~full ~opens ~rawOpens ~allFiles ~pos ~env
+           ~exact:true ~scope
+      |> completionsGetCompletionType ~full
+    with
+    | None -> []
+    | Some (typ, env) ->
+      [
+        Completion.create "dummy" ~env
+          ~kind:(Completion.ExtractedType (Toption (env, typ), `Type));
+      ])
   | CPId (path, completionContext) ->
     path
     |> getCompletionsForPath ~package ~opens ~allFiles ~pos ~exact

analysis/src/SharedTypes.ml

@@ -589,6 +589,7 @@ module Completable = struct
     | CPArray
     | CPInt
     | CPFloat
+    | CPOption of contextPath
     | CPApply of contextPath * Asttypes.arg_label list
     | CPId of string list * completionContext
     | CPField of contextPath * string
@@ -662,6 +663,7 @@ module Completable = struct
       | CPString -> "string"
       | CPInt -> "int"
       | CPFloat -> "float"
+      | CPOption ctxPath -> "option<" ^ contextPathToString ctxPath ^ ">"
       | CPApply (cp, labels) ->
         contextPathToString cp ^ "("
         ^ (labels

analysis/src/TypeUtils.ml

@@ -379,10 +379,13 @@ let typeIsUnit (typ : Types.type_expr) =
     true
   | _ -> false
 
-let contextPathFromCoreType (coreType : Parsetree.core_type) =
+let rec contextPathFromCoreType (coreType : Parsetree.core_type) =
   match coreType.ptyp_desc with
-  | Ptyp_constr (lid, []) ->
-    Some (Completable.CPId (lid.txt |> Utils.flattenLongIdent, Type))
+  | Ptyp_constr ({txt = Lident "option"}, [innerTyp]) ->
+    innerTyp |> contextPathFromCoreType
+    |> Option.map (fun innerTyp -> Completable.CPOption innerTyp)
+  | Ptyp_constr (lid, _) ->
+    Some (CPId (lid.txt |> Utils.flattenLongIdent, Type))
   | _ -> None
 
 let printRecordFromFields ?name (fields : field list) =

analysis/tests/src/CompletionTypeAnnotation.res

@@ -37,3 +37,6 @@ type someTuple = (bool, option<bool>)
 
 // let x: someTuple = (true, )
 //                          ^com
+
+// let x: option<someVariant> =
+//                             ^com

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

@@ -168,3 +168,38 @@ Completable: Cexpression Type[someTuple]->tuple($1)
     "documentation": null
   }]
 
+Complete src/CompletionTypeAnnotation.res 40:31
+XXX Not found!
+Completable: Cexpression option<Type[someVariant]>
+[{
+    "label": "None",
+    "kind": 4,
+    "tags": [],
+    "detail": "type someVariant = One | Two(bool)",
+    "documentation": null
+  }, {
+    "label": "Some(_)",
+    "kind": 4,
+    "tags": [],
+    "detail": "type someVariant = One | Two(bool)",
+    "documentation": null,
+    "insertText": "Some(${1:_})",
+    "insertTextFormat": 2
+  }, {
+    "label": "Some(One)",
+    "kind": 4,
+    "tags": [],
+    "detail": "One\n\ntype someVariant = One | Two(bool)",
+    "documentation": null,
+    "insertText": "Some(One)",
+    "insertTextFormat": 2
+  }, {
+    "label": "Some(Two(_))",
+    "kind": 4,
+    "tags": [],
+    "detail": "Two(bool)\n\ntype someVariant = One | Two(bool)",
+    "documentation": null,
+    "insertText": "Some(Two(${1:_}))",
+    "insertTextFormat": 2
+  }]
+