more sustainable fix, that also covers completions for all stdlib modules

Author: zth

analysis/src/TypeUtils.ml

@@ -1265,4 +1265,9 @@ let completionPathFromMaybeBuiltin path =
   | Some ("result", _) -> Some ["Stdlib"; "Result"]
   | Some ("dict", _) -> Some ["Stdlib"; "Dict"]
   | Some ("char", _) -> Some ["Stdlib"; "Char"]
-  | _ -> None
+  | _ -> (
+    match path |> Utils.expandPath |> List.rev with
+    | [mainModule; "t"] when String.starts_with ~prefix:"Stdlib_" mainModule ->
+      (* Route Stdlib_X to Stdlib.X for proper completions without the Stdlib_ prefix *)
+      Some (String.split_on_char '_' mainModule)
+    | _ -> None)

compiler/frontend/ast_literal.ml

@@ -71,7 +71,7 @@ module Lid = struct
   let js_null_undefined : t = Ldot (Lident "Js", "null_undefined")
 
   (* FIXME: Use primitive module *)
-  let js_re_id : t = Ldot (Lident "RegExp", "t")
+  let js_re_id : t = Ldot (Lident "Stdlib_RegExp", "t")
 end
 
 module No_loc = struct

tests/analysis_tests/tests/src/expected/CompletionRegexp.res.txt

@@ -6,7 +6,6 @@ Resolved opens 1 Stdlib
 ContextPath Value[emailPattern]->
 ContextPath Value[emailPattern]
 Path emailPattern
-CPPipe pathFromEnv:Stdlib.RegExp found:false
 Path Stdlib.RegExp.
 [{
     "label": "RegExp.lastIndex",