Decode package fields consistently (#12625)

* refactor: Use [Stanza_pkg].field_opt consistently

Signed-off-by: Rudi Grinberg <[email protected]>

Author: rgrinberg

src/dune_lang/stanza_pkg.ml

@@ -89,30 +89,7 @@ let resolve (project : Dune_project.t) mask (loc, name) =
                   (Package.Name.Map.keys packages |> List.map ~f:Package.Name.to_string)))
 ;;
 
-let decode =
-  let open Decoder in
-  let+ p = Dune_project.get_exn ()
-  and+ mask = Package_mask.decode ()
-  and+ loc, name = located Package.Name.decode in
-  match resolve p mask (loc, name) with
-  | Ok x -> x
-  | Error e -> raise (User_error.E e)
-;;
-
-let field ~stanza =
-  let open Decoder in
-  let* mask = Package_mask.decode () in
-  map_validate
-    (let+ p = Dune_project.get_exn ()
-     and+ pkg = field_o "package" (located Package.Name.decode) in
-     p, pkg)
-    ~f:(fun (p, pkg) ->
-      match pkg with
-      | None -> default p stanza
-      | Some name -> resolve p mask name)
-;;
-
-let field_opt ?check () =
+let field_opt ?check project =
   let open Decoder in
   let decode =
     let decode = Package.Name.decode in
@@ -122,11 +99,24 @@ let field_opt ?check () =
   in
   let* mask = Package_mask.decode () in
   map_validate
-    (let+ p = Dune_project.get_exn ()
-     and+ pkg = field_o "package" (located decode) in
-     p, pkg)
-    ~f:(fun (p, pkg) ->
+    (field_o "package" (located decode))
+    ~f:(fun pkg ->
       match pkg with
       | None -> Ok None
-      | Some name -> resolve p mask name |> Result.map ~f:Option.some)
+      | Some ((loc, _name) as name) ->
+        resolve project mask name |> Result.map ~f:(fun p -> Some (loc, p)))
+;;
+
+let field ~stanza =
+  let open Decoder in
+  let* project = Dune_project.get_exn () in
+  map_validate (field_opt project) ~f:(function
+    | None -> default project stanza
+    | Some (_, p) -> Ok p)
+;;
+
+let field_opt ?check () =
+  let open Decoder in
+  let* project = Dune_project.get_exn () in
+  field_opt ?check project
 ;;

src/dune_lang/stanza_pkg.mli

@@ -1,13 +1,16 @@
 open Import
 
-val decode : Package.t Decoder.t
-
 val resolve
   :  Dune_project.t
   -> Package_mask.t
   -> Loc.t * Package.Name.t
   -> (Package.t, User_message.t) Result.t
 
 val field : stanza:string -> Package.t Decoder.fields_parser
-val field_opt : ?check:unit Decoder.t -> unit -> Package.t option Decoder.fields_parser
+
+val field_opt
+  :  ?check:unit Decoder.t
+  -> unit
+  -> (Loc.t * Package.t) option Decoder.fields_parser
+
 val default_exn : loc:Loc.t -> Dune_project.t -> string -> Package.t

src/dune_lang/stanzas/alias_conf.ml

@@ -23,7 +23,7 @@ let decode =
      String_with_vars.add_user_vars_to_decoding_env
        (Bindings.var_names deps)
        (let+ name = field "name" Alias.decode
-        and+ package = field_o "package" Stanza_pkg.decode
+        and+ package = Stanza_pkg.field_opt () >>| Option.map ~f:snd
         and+ action =
           field_o
             "action"

src/dune_rules/coq/coq_stanza.ml

@@ -240,7 +240,7 @@ module Theory = struct
   let decode =
     fields
       (let+ name = field "name" Coq_lib_name.decode
-       and+ package = field_o "package" Stanza_pkg.decode
+       and+ package = Stanza_pkg.field_opt () >>| Option.map ~f:snd
        and+ project = Dune_project.get_exn ()
        and+ public = coq_public_decode
        and+ synopsis = field_o "synopsis" string

src/dune_rules/cram/cram_stanza.ml

@@ -79,6 +79,7 @@ let decode =
      and+ locks = Locks.field ~check:(Dune_lang.Syntax.since Stanza.syntax (2, 9)) ()
      and+ package =
        Stanza_pkg.field_opt ~check:(Dune_lang.Syntax.since Stanza.syntax (2, 8)) ()
+       >>| Option.map ~f:snd
      and+ runtest_alias =
        field_o
          "runtest_alias"

src/dune_rules/mdx.ml

@@ -237,6 +237,7 @@ let decode =
      and+ enabled_if = Enabled_if.decode ~allowed_vars:Any ~since:(Some (2, 9)) ()
      and+ package =
        Stanza_pkg.field_opt () ~check:(Dune_lang.Syntax.since Stanza.syntax (2, 9))
+       >>| Option.map ~f:snd
      and+ packages =
        field
          ~default:[]

src/dune_rules/melange/melange_stanzas.ml

@@ -112,7 +112,7 @@ module Emit = struct
          field "module_systems" module_systems ~default:[ Melange.Module_system.default ]
        and+ libraries =
          field "libraries" (Lib_dep.L.decode ~allow_re_export:false) ~default:[]
-       and+ package = field_o "package" Stanza_pkg.decode
+       and+ package = Stanza_pkg.field_opt () >>| Option.map ~f:snd
        and+ runtime_deps =
          field
            "runtime_deps"

src/dune_rules/stanzas/executables.ml

@@ -81,12 +81,7 @@ end = struct
     let+ names = if multi then multi_fields else single_fields
     and+ loc = loc
     and+ dune_syntax = Dune_lang.Syntax.get_exn Stanza.syntax
-    and+ package =
-      field_o
-        "package"
-        (let+ loc = loc
-         and+ pkg = Stanza_pkg.decode in
-         loc, pkg)
+    and+ package = Stanza_pkg.field_opt ()
     and+ project = Dune_project.get_exn () in
     let names, public_names = names in
     let names =

src/dune_rules/stanzas/library.ml

@@ -213,9 +213,7 @@ let decode =
          (Dune_lang.Syntax.since Stanza.syntax (2, 7)
           >>> fields (field "ppx" (located Lib_name.decode)))
      and+ package =
-       field_o
-         "package"
-         (Dune_lang.Syntax.since Stanza.syntax (2, 8) >>> located Stanza_pkg.decode)
+       Stanza_pkg.field_opt ~check:(Dune_lang.Syntax.since Stanza.syntax (2, 8)) ()
      and+ melange_runtime_deps =
        field
          "melange.runtime_deps"

src/dune_rules/stanzas/parameter.ml

@@ -83,7 +83,7 @@ let decode =
        }
      and+ name = field_o "name" Lib_name.Local.decode_loc
      and+ public = field_o "public_name" (Public_lib.decode ~allow_deprecated_names:false)
-     and+ package = field_o "package" (located Stanza_pkg.decode)
+     and+ package = Stanza_pkg.field_opt ()
      and+ enabled_if = Enabled_if.decode ~allowed_vars:Any ~since:None ()
      and+ synopsis = field_o "synopsis" string
      and+ optional = field_b "optional" in