Improve type-enclosing for record labels

CHANGES.md

@@ -4,6 +4,8 @@ unreleased
 
   + merlin binary
     - Update internal typer to match OCaml 4.14.1 release. (#1557)
+    - Improve type-enclosing behaviour when used on records' labels (#1565,
+      fixes #1564)
 
 merlin 4.7
 ==========

src/analysis/type_enclosing.ml

@@ -102,6 +102,11 @@ let from_reconstructed ~nodes ~cursor ~verbosity exprs =
         let ppf, to_string = Format.to_string () in
         Type_utils.print_constr ~verbosity env ppf cd;
         Some (loc, String (to_string ()), `No)
+      | Some (Context.Label { lbl_name; lbl_arg; _ }) ->
+        log ~title:"from_reconstructed" "ctx: label %s" lbl_name;
+        let ppf, to_string = Format.to_string () in
+        Type_utils.print_type_with_decl ~verbosity env ppf lbl_arg;
+        Some (loc, String (to_string ()), `No)
       | Some Context.Constant -> None
       | _ ->
         let context = Option.value ~default:Context.Expr context in

tests/test-dirs/type-enclosing/issue1564.t

@@ -0,0 +1,53 @@
+  $ cat >main.ml <<EOF
+  > module Kind = struct
+  >   type t =
+  >     | A
+  >     | B
+  > end
+  > type t = { kind : Kind.t }
+  > let x = { kind = A }
+  > let y = x.kind
+  > let z = { kind = B }.kind
+  > EOF
+
+On `let |y = x.kind`
+Verbosity 0 stops at Kind.t
+  $ $MERLIN single type-enclosing -position 8:4 -verbosity 0 \
+  > -filename ./main.ml < ./main.ml | tr '\r\n' ' ' | jq ".value[0].type"
+  "Kind.t"
+
+On `let |y = x.kind`
+Verbosity 1 shows the actual type definition of Kind.t
+  $ $MERLIN single type-enclosing -position 8:4 -verbosity 1 \
+  > -filename ./main.ml < ./main.ml | tr '\r\n' ' ' | jq ".value[0].type"
+  "type t = A | B"
+
+On `let y = x.k|ind`
+  $ $MERLIN single type-enclosing -position 8:11 -verbosity 0 \
+  > -filename ./main.ml < ./main.ml | tr '\r\n' ' ' | jq ".value[0].type"
+  "Kind.t"
+
+On `let y = x.k|ind`
+  $ $MERLIN single type-enclosing -position 8:11 -verbosity 1 \
+  > -filename ./main.ml < ./main.ml | tr '\r\n' ' ' | jq ".value[0].type"
+  "type t = A | B"
+
+On `let z = { kind = B }.k|ind`
+  $ $MERLIN single type-enclosing -position 9:22 -verbosity 0 \
+  > -filename ./main.ml < ./main.ml | tr '\r\n' ' ' | jq ".value[0].type"
+  "Kind.t"
+
+On `let z = { kind = B }.k|ind`
+  $ $MERLIN single type-enclosing -position 9:22 -verbosity 1 \
+  > -filename ./main.ml < ./main.ml | tr '\r\n' ' ' | jq ".value[0].type"
+  "type t = A | B"
+
+On `let x = { k|ind = A }`
+  $ $MERLIN single type-enclosing -position 7:12 -verbosity 0 \
+  > -filename ./main.ml < ./main.ml | tr '\r\n' ' ' | jq ".value[0].type"
+  "Kind.t"
+
+On `let x = { k|ind = A }`
+  $ $MERLIN single type-enclosing -position 7:12 -verbosity 1 \
+  > -filename ./main.ml < ./main.ml | tr '\r\n' ' ' | jq ".value[0].type"
+  "type t = A | B"

tests/test-dirs/type-enclosing/record.t/run.t

@@ -231,7 +231,7 @@ FIXME: The following results are not entirely satisfying (`foo.Bar -> foo` could
         "line": 12,
         "col": 18
       },
-      "type": "unit",
+      "type": "type unit = ()",
       "tail": "no"
     },
     {