Implement support for OPAM files in opam/ folder

CHANGES.md

@@ -3,6 +3,8 @@
 ### Added
 
 - Adopt the OCaml Code of Conduct (#473, @rikusilvola)
+- Added support for projects that have their OPAM files in the `opam/`
+  subdirectory. (#466, @Leonidas-from-XIV)
 
 ### Changed
 

dune-project

@@ -25,6 +25,11 @@ with [Dune](https://github.com/ocaml/dune) and hosted on
 [GitHub](https://github.com).")
  (depends
   (ocaml (>= 4.08.0))
+  ;; two dependencies on dune to work around
+  ;; https://github.com/ocaml/dune/issues/3431
+  dune
+  ;; the tests require dune 3.8
+  (dune (and (>= 3.8) :with-test))
   (curly (>= 0.3.0))
   (fmt (>= 0.8.7))
   (fpath (>= 0.7.3))

dune-release.opam

@@ -18,8 +18,9 @@ license: "ISC"
 homepage: "https://github.com/tarides/dune-release"
 bug-reports: "https://github.com/tarides/dune-release/issues"
 depends: [
-  "dune" {>= "2.7"}
   "ocaml" {>= "4.08.0"}
+  "dune" {>= "2.7"}
+  "dune" {>= "3.8" & with-test}
   "curly" {>= "0.3.0"}
   "fmt" {>= "0.8.7"}
   "fpath" {>= "0.7.3"}

lib/pkg.ml

@@ -91,7 +91,13 @@ let readme p =
 let opam p =
   match p.opam with
   | Some f -> Ok f
-  | None -> name p >>| fun name -> Fpath.v (name ^ ".opam")
+  | None ->
+      name p >>= fun name ->
+      let filename = name |> Fpath.v |> Fpath.add_ext ".opam" in
+      let opam_subdir = Fpath.v "opam" in
+      let in_opam_subdir = Fpath.append opam_subdir filename in
+      OS.File.exists in_opam_subdir
+      |> Result.map (function true -> in_opam_subdir | false -> filename)
 
 let opam_descr p =
   let descr_file_for_opam opam =
@@ -263,16 +269,26 @@ let dune_project_name dir =
 
 let infer_pkg_names dir = function
   | [] ->
-      Bos.OS.Dir.contents ~dotfiles:false ~rel:false dir >>= fun files ->
-      let files = List.fast_sort Fpath.compare files |> List.rev in
-      let opam_files =
-        List.filter
-          (fun p -> String.is_suffix ~affix:".opam" Fpath.(to_string p))
-          files
+      let remove_extension =
+        List.map (fun p -> Fpath.(basename @@ rem_ext p))
+      in
+      let collect dir =
+        Bos.OS.Dir.contents ~dotfiles:false ~rel:false dir >>= fun files ->
+        let files = List.fast_sort Fpath.compare files |> List.rev in
+        let opam_files =
+          List.filter
+            (fun p -> String.is_suffix ~affix:".opam" Fpath.(to_string p))
+            files
+        in
+        Ok (remove_extension opam_files)
       in
-      if opam_files = [] then
-        Rresult.R.error_msg "no <package>.opam files found."
-      else Ok (List.map (fun p -> Fpath.(basename @@ rem_ext p)) opam_files)
+      Result.bind (collect dir) (function
+        | [] ->
+            let opam_subdir = Fpath.(dir / "opam") in
+            Result.bind (collect opam_subdir) (function
+              | [] -> Rresult.R.error_msg "no <package>.opam files found."
+              | opam_files -> Ok opam_files)
+        | opam_files -> Ok opam_files)
   | x -> Ok x
 
 let infer_from_opam_files dir =
@@ -403,11 +419,24 @@ let prepare_opam_for_distrib ~version ~content =
   let without_version = List.filter is_not_version_field content in
   Fmt.str "version: \"%a\"" Version.pp version :: without_version
 
+let opam_file_contents name =
+  let filename = name |> Fpath.v |> Fpath.add_ext ".opam" in
+  let location =
+    OS.File.exists filename >>= function
+    | true -> Ok filename
+    | false -> (
+        let filename = Fpath.append (Fpath.v "opam") filename in
+        OS.File.exists filename >>= function
+        | true -> Ok filename
+        | false -> Rresult.R.error_msgf "Can't open %a" Fpath.pp filename)
+  in
+  location >>= fun filename ->
+  OS.File.read_lines filename >>| fun content -> (filename, content)
+
 let distrib_version_opam_files ~dry_run ~version =
   infer_pkg_names Fpath.(v ".") [] >>= fun names ->
   Stdext.Result.List.iter names ~f:(fun name ->
-      let file = Fpath.(v name + "opam") in
-      OS.File.read_lines file >>= fun content ->
+      opam_file_contents name >>= fun (file, content) ->
       let content = prepare_opam_for_distrib ~version ~content in
       Sos.write_file ~dry_run file (String.concat ~sep:"\n" content))
 

tests/bin/opam-file-locations/dune

@@ -0,0 +1,8 @@
+(env
+ (_
+  (binaries
+   (../helpers/make_dune_release_deterministic.exe as
+     make_dune_release_deterministic))))
+
+(cram
+ (deps %{bin:dune-release} %{bin:make_dune_release_deterministic}))

tests/bin/opam-file-locations/run.t

@@ -0,0 +1,102 @@
+Set up a project with an `.opam` file in the toplevel folder:
+
+  $ cat > CHANGES.md << EOF
+  > ## 0.1.0
+  > 
+  > - Initial release
+  > 
+  > EOF
+  $ cat > dune-project << EOF
+  > (lang dune 3.8)
+  > (name myproject)
+  > EOF
+  $ cat > myproject.opam << EOF
+  > opam-version: "2.0"
+  > EOF
+  $ git init 2> /dev/null . > /dev/null
+  $ touch README LICENSE
+  $ cat > .gitignore << EOF
+  > _build
+  > .bin
+  > /dune
+  > run.t
+  > EOF
+  $ git add CHANGES.md README LICENSE *.opam dune-project .gitignore
+  $ git commit -m 'Initial commit' > /dev/null
+
+Tagging should work
+
+  $ dune-release tag -y
+  [-] Extracting tag from first entry in CHANGES.md
+  [-] Using tag "0.1.0"
+  [+] Tagged HEAD with version 0.1.0
+
+`dune-release distrib` should work.
+
+  $ dune-release distrib --skip-lint | make_dune_release_deterministic
+  [-] Building source archive
+  [+] Wrote archive _build/myproject-0.1.0.tbz
+
+  [-] Building package in _build/myproject-0.1.0
+  [ OK ] package(s) build
+
+  [-] Running package tests in _build/myproject-0.1.0
+  [ OK ] package(s) pass the tests
+
+  [+] Distribution for myproject 0.1.0
+  [+] Commit <deterministic>
+  [+] Archive _build/myproject-0.1.0.tbz
+
+Now let's move the `.opam` file to the `opam/` subfolder. OPAM supports `.opam`
+files in the `opam/` subfolder, but for dune to pick it up we need to tell it
+to look in that folder.
+
+Importantly, dune requires the packages in the `opam/` folder to be declared in
+`dune-project` as `package`.
+
+  $ cat  > CHANGES.md << EOF
+  > ## 0.2.0
+  > 
+  > - Use dune to generate opam file in opam subfolder
+  > 
+  > EOF
+  $ cat >> dune-project << EOF
+  > (package
+  >   (name myproject)
+  >   (allow_empty))
+  > (generate_opam_files true)
+  > (opam_file_location inside_opam_directory)
+  > EOF
+  $ git rm myproject.opam
+  rm 'myproject.opam'
+  $ dune build opam/myproject.opam
+  $ git add opam/myproject.opam CHANGES.md dune-project
+  $ git commit -m 'Opam file in subfolder' > /dev/null
+
+Now we should still be able to tag:
+
+  $ dune-release tag -y
+  [-] Extracting tag from first entry in CHANGES.md
+  [-] Using tag "0.2.0"
+  [+] Tagged HEAD with version 0.2.0
+
+And as well have a release tarball
+
+  $ dune-release distrib --skip-lint | make_dune_release_deterministic
+  [-] Building source archive
+  [+] Wrote archive _build/myproject-0.2.0.tbz
+
+  [-] Building package in _build/myproject-0.2.0
+  [ OK ] package(s) build
+
+  [-] Running package tests in _build/myproject-0.2.0
+  [ OK ] package(s) pass the tests
+
+  [+] Distribution for myproject 0.2.0
+  [+] Commit <deterministic>
+  [+] Archive _build/myproject-0.2.0.tbz
+
+Which contains the `.opam` file in the right location:
+
+  $ tar tf _build/myproject-0.2.0.tbz | grep \\.opam
+  myproject-0.2.0/opam/myproject.opam