Add lint for the x-reason-for-archiving field

opam-ci-check/lib/lint.ml

@@ -360,8 +360,25 @@ module Checks = struct
       )
       []
 
-  let check_x_reason_for_archival ~pkg:_ _opam =
-    [] (* TODO *)
+  let check_x_reason_for_archival ~pkg opam =
+    let is_valid_reason (item : OpamParserTypes.FullPos.value) =
+      match item.pelem with
+      | String reason -> List.mem reason x_reason_for_archiving_valid_reasons
+      | _ -> false (* Must be a string *)
+    in
+    opam
+    |> OpamFile.OPAM.extensions
+    |> OpamStd.String.Map.find_opt x_reason_for_archiving_field
+    |> function
+    | None ->
+      [(pkg, InvalidReasonForArchiving)] (* Field must be present *)
+    | Some field ->
+      match field.pelem with
+      (* Must be a non-empty list of valid reasons *)
+      | List {pelem = (_::_ as reasons); _} when List.for_all is_valid_reason reasons -> []
+      | _ -> [(pkg, InvalidReasonForArchiving)]
+
+
   let x_opam_repository_commit_hash_at_time_of_archival ~pkg:_ _opam  =
     [] (* TODO *)
 

opam-ci-check/lib/lint_error.ml

@@ -37,9 +37,15 @@ type error =
   | PrefixConflictClassMismatch of prefix_conflict_class_mismatch
   | DefaultTagsPresent of string list
   | MissingUpperBound of string
+  | InvalidReasonForArchiving
 
 (**/**)
 
+let x_reason_for_archiving_field = "x-reason-for-archiving"
+(* Used in the opam repo archive *)
+let x_reason_for_archiving_valid_reasons =
+  ["ocaml-version"; "source-unavailable"; "maintenance-intent"; "uninstallable" ]
+
 let msg_of_prefix_conflict_class_mismatch ~pkg = function
   | WrongPrefix { conflict_class; required_prefix } ->
       Printf.sprintf
@@ -168,3 +174,9 @@ let msg_of_error (package, (err : error)) =
       Printf.sprintf
         "Error in %s: An upper bound constraint is missing on dependency '%s'"
         pkg dep_name
+  | InvalidReasonForArchiving ->
+      Printf.sprintf
+        "Error in %s: The field '%s' must be present and hold a nonempty list \
+         of one or more of the valid reasons %s"
+        pkg x_reason_for_archiving_field
+        (String.concat ", " x_reason_for_archiving_valid_reasons)

opam-ci-check/test/lint.t

@@ -356,14 +356,36 @@ passes linting:
 
 # Opam Archive linting tests
 
-  $ git reset -q --hard initial-state
+These linting checks automate enforcement of the opam archiving policy found at
+https://github.com/ocaml/opam-repository/blob/master/governance/policies/archiving.md#archiving-a-package
 
-Test that we do not report an error when a wellformed package has no deps:
+  $ git reset -q --hard initial-state
 
+Test that we do not report an error on a minimal well-formed package:
+
+  $ echo 'x-reason-for-archiving: [ "source-unavailable" ]' >> packages/a-1/a-1.0.0.1/opam
+  $ cat packages/a-1/a-1.0.0.1/opam
+  opam-version: "2.0"
+  synopsis: "Synopsis"
+  description: "Description"
+  maintainer: "Maintainer <me@example.com>"
+  author: "Author"
+  license: "Apache-2.0"
+  homepage: "https://github.com/ocurrent/opam-repo-ci"
+  bug-reports: "https://github.com/ocurrent/opam-repo-ci/issues"
+  dev-repo: "git+https://github.com/ocurrent/opam-repo-ci.git"
+  doc: "https://ocurrent.github.io/ocurrent/"
+  build: []
+  depends: []
+  x-reason-for-archiving: [ "source-unavailable" ]
   $ opam-ci-check lint -r . --check=archive-repo a-1.0.0.1
   Linting opam-repository at $TESTCASE_ROOT/. ...
   No errors
 
+## Upper bounds checks
+
+All dependencies
+
 Test that we report errors when a package has dependandies without an upper bound:
 
   $ sed \
@@ -387,7 +409,7 @@ Test that we do NOT report errors when all a packages dependandies have an upper
   Linting opam-repository at $TESTCASE_ROOT/. ...
   No errors
 
-Test that we do NOT report errors when the ocaml dependency has no upper bound:
+Test that we do NOT report errors when the compiler dependency has no upper bound:
 
   $ sed \
   > -e 's/depends.*/depends: ["ocaml"]/' \
@@ -396,3 +418,46 @@ Test that we do NOT report errors when the ocaml dependency has no upper bound:
   $ opam-ci-check lint -r . --check=archive-repo a-1.0.0.1
   Linting opam-repository at $TESTCASE_ROOT/. ...
   No errors
+
+## x-reason-for-archiving checks
+
+Test we report an error when the x-reason-for-archiving is missing:
+
+  $ sed \
+  > -e '/x-reason-for-archiving/d' \
+  > packages/a-1/a-1.0.0.1/opam > opam.new
+  $ mv opam.new packages/a-1/a-1.0.0.1/opam
+  $ opam-ci-check lint -r . --check=archive-repo a-1.0.0.1
+  Linting opam-repository at $TESTCASE_ROOT/. ...
+  Error in a-1.0.0.1: The field 'x-reason-for-archiving' must be present and hold a nonempty list of one or more of the valid reasons ocaml-version, source-unavailable, maintenance-intent, uninstallable
+  [1]
+
+Test we report an error when the x-reason-for-archiving has an invalid value:
+
+  $ echo 'x-reason-for-archiving: "not a list"' >> packages/a-1/a-1.0.0.1/opam
+  $ opam-ci-check lint -r . --check=archive-repo a-1.0.0.1
+  Linting opam-repository at $TESTCASE_ROOT/. ...
+  Error in a-1.0.0.1: The field 'x-reason-for-archiving' must be present and hold a nonempty list of one or more of the valid reasons ocaml-version, source-unavailable, maintenance-intent, uninstallable
+  [1]
+
+Test we report an error when the x-reason-for-archiving has an empty list:
+
+  $ sed \
+  > -e 's/x-reason-for-archiving:.*/x-reason-for-archiving: []/' \
+  > packages/a-1/a-1.0.0.1/opam > opam.new
+  $ mv opam.new packages/a-1/a-1.0.0.1/opam
+  $ opam-ci-check lint -r . --check=archive-repo a-1.0.0.1
+  Linting opam-repository at $TESTCASE_ROOT/. ...
+  Error in a-1.0.0.1: The field 'x-reason-for-archiving' must be present and hold a nonempty list of one or more of the valid reasons ocaml-version, source-unavailable, maintenance-intent, uninstallable
+  [1]
+
+Test we report an error when the x-reason-for-archiving has an invalid reason:
+
+  $ sed \
+  > -e 's/x-reason-for-archiving:.*/x-reason-for-archiving: ["an indalid reason"]/' \
+  > packages/a-1/a-1.0.0.1/opam > opam.new
+  $ mv opam.new packages/a-1/a-1.0.0.1/opam
+  $ opam-ci-check lint -r . --check=archive-repo a-1.0.0.1
+  Linting opam-repository at $TESTCASE_ROOT/. ...
+  Error in a-1.0.0.1: The field 'x-reason-for-archiving' must be present and hold a nonempty list of one or more of the valid reasons ocaml-version, source-unavailable, maintenance-intent, uninstallable
+  [1]