unikernel/duniverse/ocaml-caqti/caqti/test/test_switch.ml

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+(* Copyright (C) 2023  Petter A. Urkedal <paurkedal@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version, with the LGPL-3.0 Linking Exception.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * and the LGPL-3.0 Linking Exception along with this library.  If not, see
+ * <http://www.gnu.org/licenses/> and <https://spdx.org>, respectively.
+ *)
+
+module A = Alcotest.V1
+
+module Switch = Caqti_platform.Switch.Make (struct
+  type 'a t = 'a
+  let return = Fun.id
+  module Infix = struct
+    let (>>=) m f = f m
+  end
+  let finally f h = try let y = f () in h (); y with exn -> h (); raise exn
+end)
+
+let test_switch sw =
+  Switch.check sw;
+  let state = ref 0 in
+  let transit i j () = A.(check int) "transit" i !state; state := j in
+  let _ = Switch.on_release_cancellable sw (transit 2 3) in
+  let hook1 = Switch.on_release_cancellable sw (fun () -> A.fail "removed") in
+  let _ = Switch.on_release_cancellable sw (transit 1 2) in
+  let hook2 = Switch.on_release_cancellable sw (fun () -> A.fail "removed") in
+  let _ = Switch.on_release_cancellable sw (transit 0 1) in
+  Switch.remove_hook hook1;
+  Switch.remove_hook hook2;
+  Switch.check sw
+
+let test_eternal () =
+  let sw = Switch.eternal in
+  let _ = Switch.on_release_cancellable sw (fun () -> A.fail "on eternal") in
+  let hook = Switch.on_release_cancellable sw (fun () -> A.fail "on eternal") in
+  Switch.remove_hook hook
+
+let test_create () =
+  let sw = Switch.create () in
+  test_switch sw;
+  Switch.release sw;
+  A.check_raises "released switch" Switch.Off (fun () -> Switch.check sw)
+
+let test_run () =
+  let sw' = ref None in
+  Switch.run begin fun sw ->
+    sw' := Some sw;
+    test_switch sw
+  end;
+  A.check_raises "outside run"
+    Switch.Off (fun () -> Option.iter Switch.check !sw')
+
+let test_cases = [
+  A.test_case "eternal" `Quick test_eternal;
+  A.test_case "create" `Quick test_create;
+  A.test_case "run" `Quick test_run;
+]