1 files changed, 62 insertions, 0 deletions
diff --git a/test/test_config.ml b/test/test_config.ml
new file mode 100644
index 0000000..9100380
--- /dev/null
+++ b/test/test_config.ml
@@ -0,0 +1,62 @@
+module C = Colitur_naming.Config
+
+let ok = function Ok x -> x | Error e -> Alcotest.failf "parse: %s" e
+
+let sample =
+  "[defaults]\n\
+   lang = pl\n\
+   overlay = ~/a.ini\n\
+   overlay = ~/b.ini\n\
+   template = ~/my-ordo.tex\n\
+   format = json\n"
+
+let test_reads_defaults () =
+  let c = ok (C.of_string sample) in
+  Alcotest.(check (option string)) "lang" (Some "pl") (C.lang c);
+  Alcotest.(check (option string)) "template" (Some "~/my-ordo.tex") (C.template c);
+  Alcotest.(check (option string)) "format" (Some "json") (C.format c)
+
+(* Repeated keys accumulate for overlay -- a user has more than one. The INI
+   reader keeps every line, so this asserts we do not silently take the last. *)
+let test_overlays_accumulate () =
+  let c = ok (C.of_string sample) in
+  Alcotest.(check (list string)) "both overlays" [ "~/a.ini"; "~/b.ini" ] (C.overlays c)
+
+let test_empty_config_is_all_none () =
+  Alcotest.(check (option string)) "lang" None (C.lang C.empty);
+  Alcotest.(check (list string)) "overlays" [] (C.overlays C.empty)
+
+(* THE precedence rule: flag > config > default, and the SOURCE is reported,
+   because a setting that silently comes from a file the user forgot about is
+   worse than no setting at all. *)
+let test_precedence_and_provenance () =
+  let check ~flag ~config ~default (ev, es) =
+    let v, s = C.resolve ~flag ~config ~default in
+    Alcotest.(check string) "value" ev v;
+    Alcotest.(check string) "source" es s
+  in
+  check ~flag:(Some "en") ~config:(Some "pl") ~default:"la" ("en", "flag");
+  check ~flag:None ~config:(Some "pl") ~default:"la" ("pl", "config");
+  check ~flag:None ~config:None ~default:"la" ("la", "default")
+
+let test_malformed_is_error_not_crash () =
+  match C.of_string "[defaults\nbroken" with
+  | Error _ -> ()
+  | Ok _ -> Alcotest.fail "a malformed config must be an Error, never accepted"
+
+(* An unknown key is a WARNING case, not a hard error: a config written for a
+   newer colitur must still work on an older one. But it must be reportable, so
+   it is not silently dropped either. *)
+let test_unknown_key_is_reported_not_fatal () =
+  match C.of_string "[defaults]\nlang = la\nnonsense = 1\n" with
+  | Error _ -> Alcotest.fail "an unknown key must not be fatal"
+  | Ok c -> Alcotest.(check (option string)) "known key still read" (Some "la") (C.lang c)
+
+let suite =
+  ( "Config",
+    [ Alcotest.test_case "reads defaults" `Quick test_reads_defaults;
+      Alcotest.test_case "overlays accumulate" `Quick test_overlays_accumulate;
+      Alcotest.test_case "empty is all none" `Quick test_empty_config_is_all_none;
+      Alcotest.test_case "precedence and provenance" `Quick test_precedence_and_provenance;
+      Alcotest.test_case "malformed is error" `Quick test_malformed_is_error_not_crash;
+      Alcotest.test_case "unknown key not fatal" `Quick test_unknown_key_is_reported_not_fatal ] )