Use the env (and cmis) to traverse module aliases

Co-authored-by: Leo White <leo@lpw25.net>

Author: voodoos

src/analysis/locate.ml

@@ -310,6 +310,16 @@ let load_cmt ~config comp_unit ml_or_mli =
       Ok (source_file, cmt_infos)
   | None -> Error ()
 
+let find_declaration_uid ~env ~decl_uid path =
+  let rec non_alias_declaration_uid path =
+    let md = Env.find_module path env in
+    match md.md_type with
+    | Mty_ident _ | Mty_signature _ | Mty_functor _ | Mty_for_hole -> md.md_uid
+    | Mty_alias path -> non_alias_declaration_uid path
+  in
+  try non_alias_declaration_uid path
+with Not_found -> decl_uid
+
 let uid_of_path ~config ~env ~ml_or_mli ~decl_uid path ns =
   let module Shape_reduce =
     Shape.Make_reduce (struct
@@ -333,7 +343,7 @@ let uid_of_path ~config ~env ~ml_or_mli ~decl_uid path ns =
     end)
   in
   match ml_or_mli with
-  | `MLI -> Some decl_uid
+  | `MLI -> Some (find_declaration_uid ~decl_uid ~env path)
   | `ML ->
     let shape = Env.shape_of_path ~namespace:ns env path in
     log ~title:"shape_of_path" "initial: %a"

tests/test-dirs/locate/module-aliases.t/run.t

@@ -65,12 +65,11 @@ Jump to an aliased module `A|.f`:
   }
 
 Jump to the declaration of an aliased module `A|.f`.
-With the new shape implementation it is expected that we jump to the 
-declaration of the alias and not to the aliased module itself.
+The alias is traversed.
   $ $MERLIN single locate -look-for mli -position 5:2 \
   > -filename ./main.ml < ./main.ml | jq '.value'
   {
-    "file": "$TESTCASE_ROOT/main.ml",
+    "file": "$TESTCASE_ROOT/anothermod.mli",
     "pos": {
       "line": 1,
       "col": 0
@@ -168,12 +167,11 @@ Jump to an aliased module `A|.f`:
   }
 
 Jump to the declaration of an aliased module `A|.f`:
-With the new shape implementation it is expected that we jump to the
-declaration of the alias and not to the aliased module itself.
+The alias is traversed.
   $ $MERLIN single locate -look-for mli -position 5:2 \
   > -filename ./main.ml < ./main.ml | jq '.value'
   {
-    "file": "$TESTCASE_ROOT/main.ml",
+    "file": "$TESTCASE_ROOT/anothermod.mli",
     "pos": {
       "line": 1,
       "col": 0

tests/test-dirs/locate/module-decl-aliases.t

@@ -29,14 +29,13 @@
     }
   }
 
-FIXME: it would be more useful to traverse the alias and jump to 2:2
   $ $MERLIN single locate -look-for mli -position 11:10 \
   > -filename ./main.ml < ./main.ml | jq '.value'
   {
     "file": "$TESTCASE_ROOT/main.ml",
     "pos": {
-      "line": 10,
-      "col": 0
+      "line": 2,
+      "col": 2
     }
   }
   $ $MERLIN single locate -look-for ml -position 2:10 \
@@ -49,13 +48,12 @@ FIXME: it would be more useful to traverse the alias and jump to 2:2
     }
   }
 
-FIXME: it would be more useful to traverse the alias and jump to main 2:2
   $ $MERLIN single locate -look-for mli -position 2:10 \
   > -filename ./other.ml < ./other.ml | jq '.value'
   {
-    "file": "$TESTCASE_ROOT/other.ml",
+    "file": "$TESTCASE_ROOT/main.ml",
     "pos": {
-      "line": 1,
-      "col": 0
+      "line": 2,
+      "col": 2
     }
   }