Issue #385: Increase test coverage for Lwt_result

tests/core/main.ml

@@ -25,4 +25,5 @@ Test.run "core" [
   Test_lwt_list.suite;
   Test_lwt_switch.suite;
   Test_lwt_mutex.suite;
+  Test_lwt_result.suite;
 ]

tests/core/test_lwt_result.ml

@@ -0,0 +1,147 @@
+(* OCaml promise library
+ * http://www.ocsigen.org/lwt
+ *
+ * This program 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, with linking exceptions;
+ * either version 2.1 of the License, or (at your option) any later
+ * version. See COPYING file for details.
+ *
+ * This program 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 along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *)
+
+open Test
+open Lwt
+
+exception Dummy_error
+
+let suite =
+  suite "lwt_result" [
+    test "maps"
+      (fun () ->
+         let x = Lwt_result.return 0 in
+         let correct = Lwt_result.return 1 in
+         return (Lwt_result.map ((+) 1) x = correct)
+      );
+
+    test ">|= is a variant of map"
+      (fun () ->
+         let x = Lwt_result.return 0 in
+         let correct = Lwt_result.return 1 in
+         return (Lwt_result.(>|=) x ((+) 1) = correct)
+      );
+
+    test "map, error case"
+      (fun () ->
+         let x = Lwt_result.fail 0 in
+         return (Lwt_result.map ((+) 1) x = x)
+      );
+
+    test "map_err"
+      (fun () ->
+         let x = Lwt_result.return 0 in
+         return (Lwt_result.map_err ((+) 1) x = x)
+      );
+
+    test "map_err, error case"
+      (fun () ->
+         let x = Lwt_result.fail 0 in
+         let correct = Lwt_result.fail 1 in
+         return (Lwt_result.map_err ((+) 1) x = correct)
+      );
+
+    test "bind"
+      (fun () ->
+         let x = Lwt_result.return 0 in
+         let correct = Lwt_result.return 1 in
+         let actual = Lwt_result.bind x (fun y -> Lwt_result.return (y + 1)) in
+         return (actual = correct)
+      );
+
+    test "bind, error case"
+      (fun () ->
+         let x = Lwt_result.fail 0 in
+         let actual = Lwt_result.bind x (fun y -> Lwt_result.return (y + 1)) in
+         return (actual = x)
+      );
+
+    test "ok"
+      (fun () ->
+         let x = Lwt.return 0 in
+         return (Lwt_result.ok x = Lwt_result.return 0)
+      );
+
+    test "catch"
+      (fun () ->
+         let x = Lwt.return 0 in
+         return (Lwt_result.catch x = Lwt_result.return 0)
+      );
+
+    test "catch, error case"
+      (fun () ->
+         let x = Lwt.fail Dummy_error in
+         return (Lwt_result.catch x = Lwt_result.fail Dummy_error)
+      );
+
+    test "get_exn"
+      (fun () ->
+         let x = Lwt_result.return 0 in
+         return (Lwt_result.get_exn x = Lwt.return 0)
+      );
+
+    test "get_exn, error case"
+      (fun () ->
+         let x = Lwt_result.fail Dummy_error in
+         return (Lwt_result.get_exn x = Lwt.fail Dummy_error)
+      );
+
+    test "bind_lwt"
+      (fun () ->
+         let x = Lwt_result.return 0 in
+         let f y = Lwt.return (y + 1) in
+         return (Lwt_result.bind_lwt x f = Lwt_result.return 1)
+      );
+
+    test "bind_lwt, error case"
+      (fun () ->
+         let x = Lwt_result.fail 0 in
+         let f y = Lwt.return (y + 1) in
+         return (Lwt_result.bind_lwt x f = Lwt_result.fail 0)
+      );
+
+    test "bind_lwt_err"
+      (fun () ->
+         let x = Lwt_result.return 0 in
+         let f y = Lwt.return (y + 1) in
+         return (Lwt_result.bind_lwt_err x f = Lwt_result.return 0)
+      );
+
+    test "bind_lwt_err, error case"
+      (fun () ->
+         let x = Lwt_result.fail 0 in
+         let f y = Lwt.return (y + 1) in
+         return (Lwt_result.bind_lwt_err x f = Lwt_result.fail 1)
+      );
+
+    test "bind_result"
+      (fun () ->
+         let x = Lwt_result.return 0 in
+         let f y = Result.Ok (y + 1) in
+         return (Lwt_result.bind_result x f = Lwt_result.return 1)
+      );
+
+    test "bind_result, error case"
+      (fun () ->
+         let x = Lwt_result.fail 0 in
+         let f y = Result.Ok (y + 1) in
+         return (Lwt_result.bind_result x f = Lwt_result.fail 0)
+      );
+  ]