Make pipe completion work reliably across submodules.

CHANGELOG.md

@@ -20,6 +20,7 @@
 - Accept both `@ns.doc` and the new `@res.doc` for the internal representation of doc comments. And both `@ns.optional` and `@res.optional` for the optional fields. https://github.com/rescript-lang/rescript-vscode/pull/642
 - Make pipe completion work more reliably after function calls. https://github.com/rescript-lang/rescript-vscode/pull/656
 - Make pipe completion work in pipe chains, not just on the first pipe. https://github.com/rescript-lang/rescript-vscode/pull/656
+- Make pipe completion work reliably when the path resolution needs to traverse submodules https://github.com/rescript-lang/rescript-vscode/pull/663
 
 #### :bug: Bug Fix
 

analysis/src/CompletionBackEnd.ml

@@ -1371,21 +1371,21 @@ let rec getCompletionsForContextPath ~full ~opens ~rawOpens ~allFiles ~pos ~env
           | Some path -> Some path
           | None -> (
             match expandPath typePath with
-            | _ :: rest when rest <> [] ->
-              (* Assume a non-empty type path is coming from the compiler and
-                 can be used as-is. *)
-              Some (List.rev rest)
-            | _ ->
-              (* Get the path from the comletion environment *)
-              let path = envFromCompletionItem.path in
-              if path = [] then None
+            | _ :: pathRev ->
+              (* type path is relative to the completion environment
+                 express it from the root of the file *)
+              let pathFromEnv_ =
+                QueryEnv.pathFromEnv envFromCompletionItem (List.rev pathRev)
+              in
+              if pathFromEnv_ = [] then None
               else
                 let pathFromEnv =
                   if env.file.moduleName = envFromCompletionItem.file.moduleName
-                  then path
-                  else envFromCompletionItem.file.moduleName :: path
+                  then pathFromEnv_
+                  else envFromCompletionItem.file.moduleName :: pathFromEnv_
                 in
-                Some pathFromEnv))
+                Some pathFromEnv
+            | _ -> None))
         | None -> None
       in
       match completionPath with

analysis/src/SharedTypes.ml

@@ -238,15 +238,45 @@ module File = struct
 end
 
 module QueryEnv : sig
-  type t = private {file: File.t; exported: Exported.t; path: path}
+  type t = private {
+    file: File.t;
+    exported: Exported.t;
+    pathRev: path;
+    parent: t option;
+  }
   val fromFile : File.t -> t
   val enterStructure : t -> Module.structure -> t
+
+  (* Express a path starting from the module represented by the env.
+     E.g. the env is at A.B.C and the path is D.
+     The result is A.B.C.D if D is inside C.
+     Or A.B.D or A.D or D if it's in one of its parents. *)
+  val pathFromEnv : t -> path -> path
 end = struct
-  type t = {file: File.t; exported: Exported.t; path: path}
+  type t = {file: File.t; exported: Exported.t; pathRev: path; parent: t option}
+
+  let fromFile (file : File.t) =
+    {file; exported = file.structure.exported; pathRev = []; parent = None}
+
+  (* Prune a path and find a parent environment that contains the module name *)
+  let rec prunePath pathRev env name =
+    if Exported.find env.exported Module name <> None then pathRev
+    else
+      match (pathRev, env.parent) with
+      | _ :: rest, Some env -> prunePath rest env name
+      | _ -> []
+
+  let pathFromEnv env path =
+    match path with
+    | [] -> env.pathRev |> List.rev
+    | name :: _ ->
+      let prunedPathRev = prunePath env.pathRev env name in
+      List.rev_append prunedPathRev path
 
-  let fromFile file = {file; exported = file.structure.exported; path = []}
   let enterStructure env (structure : Module.structure) =
-    {env with exported = structure.exported; path = structure.name :: env.path}
+    let name = structure.name in
+    let pathRev = name :: prunePath env.pathRev env name in
+    {env with exported = structure.exported; pathRev; parent = Some env}
 end
 
 module Completion = struct

analysis/tests/src/CompletionPipeSubmodules.res

@@ -0,0 +1,45 @@
+module A = {
+  module B1 = {
+    type b1 = B1
+    let xx = B1
+  }
+  module B2 = {
+    let yy = 20
+  }
+  type t = {v: B1.b1}
+  let x = {v: B1.B1}
+}
+
+// let _ = A.B1.xx->
+//                  ^com
+// b1 seen from B1 is A.B1.b1
+
+// let _ = A.x.v->
+//                ^com
+// B1.b1 seen from A  is A.B1.b1
+
+module C = {
+  type t = C
+}
+
+module D = {
+  module C2 = {
+    type t2 = C2
+  }
+
+  type d = {v: C.t, v2: C2.t2}
+  let d = {v: C.C, v2: C2.C2}
+}
+
+module E = {
+  type e = {v: D.d}
+  let e = {v: D.d}
+}
+
+// let _ = E.e.v.v->
+//                  ^com
+// C.t seen from D is C.t
+
+// let _ = E.e.v.v2->
+//                   ^com
+// C2.t2 seen from D is D.C2.t2

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

@@ -0,0 +1,56 @@
+Complete src/CompletionPipeSubmodules.res 12:20
+posCursor:[12:20] posNoWhite:[12:19] Found expr:[12:11->20:8]
+Completable: Cpath Value[A, B1, xx]->
+[{
+    "label": "A.B1.xx",
+    "kind": 12,
+    "tags": [],
+    "detail": "b1",
+    "documentation": null
+  }, {
+    "label": "A.B1.B1",
+    "kind": 4,
+    "tags": [],
+    "detail": "B1\n\ntype b1 = B1",
+    "documentation": null
+  }]
+
+Complete src/CompletionPipeSubmodules.res 16:18
+posCursor:[16:18] posNoWhite:[16:17] Found expr:[16:11->20:8]
+Completable: Cpath Value[A, x].v->
+[{
+    "label": "A.B1.xx",
+    "kind": 12,
+    "tags": [],
+    "detail": "b1",
+    "documentation": null
+  }, {
+    "label": "A.B1.B1",
+    "kind": 4,
+    "tags": [],
+    "detail": "B1\n\ntype b1 = B1",
+    "documentation": null
+  }]
+
+Complete src/CompletionPipeSubmodules.res 38:20
+posCursor:[38:20] posNoWhite:[38:19] Found expr:[38:11->0:-1]
+Completable: Cpath Value[E, e].v.v->
+[{
+    "label": "C.C",
+    "kind": 4,
+    "tags": [],
+    "detail": "C\n\ntype t = C",
+    "documentation": null
+  }]
+
+Complete src/CompletionPipeSubmodules.res 42:21
+posCursor:[42:21] posNoWhite:[42:20] Found expr:[42:11->0:-1]
+Completable: Cpath Value[E, e].v.v2->
+[{
+    "label": "D.C2.C2",
+    "kind": 4,
+    "tags": [],
+    "detail": "C2\n\ntype t2 = C2",
+    "documentation": null
+  }]
+