1 files changed, 75 insertions, 0 deletions
diff --git a/ocaml/test/test_state.ml b/ocaml/test/test_state.ml
new file mode 100644
index 0000000..b5c9803
--- /dev/null
+++ b/ocaml/test/test_state.ml
@@ -0,0 +1,75 @@
+open Nock_lib
+module State = Nock_lib.State
+open Noun
+
+let atom_int n = atom (Z.of_int n)
+
+let make_test_kernel ~effects ~new_core =
+  let gate_result = cell effects new_core in
+  let gate_battery = cell (atom_int 1) gate_result in
+  let gate_payload = cell (atom_int 0) (atom_int 0) in
+  let gate = cell gate_battery gate_payload in
+  let formula = cell (atom_int 0) (atom (Z.of_int 6)) in
+  let battery =
+    cell (atom_int 0)
+      (cell (atom_int 0)
+        (cell (atom_int 0) formula))
+  in
+  let payload = cell gate (atom_int 0) in
+  cell battery payload
+
+let test_boot_and_event_counter () =
+  let state = State.create () in
+  Alcotest.(check int64) "initial eve" 0L (State.event_number state);
+  let kernel = atom_int 99 in
+  State.boot state kernel;
+  Alcotest.(check bool) "kernel after boot" true (equal kernel (State.arvo_core state));
+  Alcotest.(check int64) "eve reset" 0L (State.event_number state)
+
+let test_boot_with_explicit_eve () =
+  let state = State.create () in
+  let kernel = atom_int 7 in
+  State.boot ~events_played:3L state kernel;
+  Alcotest.(check bool) "kernel after boot" true (equal kernel (State.arvo_core state));
+  Alcotest.(check int64) "eve preset" 3L (State.event_number state)
+
+let test_poke_updates_core_and_counter () =
+  let effects = atom_int 0 in
+  let new_core = atom_int 123 in
+  let kernel = make_test_kernel ~effects ~new_core in
+  Alcotest.(check bool) "axis 23" true
+    (equal (Noun.slot (Z.of_int 23) kernel) (cell (atom_int 0) (atom (Z.of_int 6))));
+  let state = State.create ~initial:kernel () in
+  let event = atom_int 42 in
+  let returned = State.poke state event in
+  Alcotest.(check bool) "effects" true (equal returned effects);
+  Alcotest.(check bool) "new core" true (equal new_core (State.arvo_core state));
+  Alcotest.(check int64) "eve increment" 1L (State.event_number state)
+
+let test_peek () =
+  let kernel = cell (atom_int 1) (atom_int 2) in
+  let state = State.create ~initial:kernel () in
+  let path = atom_int 0 in
+  match State.peek state path with
+  | Some result ->
+      Alcotest.(check bool) "peek subject" true (equal result (cell path kernel))
+  | None -> Alcotest.fail "peek should succeed"
+
+let test_snapshot_roundtrip () =
+  let kernel = cell (atom_int 5) (atom_int 6) in
+  let state = State.create ~initial:kernel () in
+  let jammed, eve = State.snapshot state in
+  Alcotest.(check int64) "snapshot eve" 0L eve;
+  let state' = State.create () in
+  State.load_snapshot state' jammed eve;
+  Alcotest.(check bool) "core restored" true (equal (State.arvo_core state') kernel)
+
+let tests = [
+  "boot", `Quick, test_boot_and_event_counter;
+  "boot preset eve", `Quick, test_boot_with_explicit_eve;
+  "poke", `Quick, test_poke_updates_core_and_counter;
+  "peek", `Quick, test_peek;
+  "snapshot", `Quick, test_snapshot_roundtrip;
+]
+
+let () = Alcotest.run "state" [ "state", tests ]