Fix mem3 tests (#1285)

The changes listener started in setup of mem3_shards test
was crashing when tried to register on unstarted couch_event
server, so the test was either fast enough to do assertions
before of that or failed on dead listener process.

This change removes dependency on mocking and uses
a standard test_util's star and stop of couch. Module start
moved into the test body to avoid masking potential failure
in a setup.

Also the tests mem3_sync_security_test and mem3_util_test
been modified to avoid setup and teardown side effects.

4 files changed, 36 insertions, 93 deletions

diff --git a/src/mem3/src/mem3_shards.erl b/src/mem3/src/mem3_shards.erl
index 0975d2f8f..c84b87397 100644
--- a/src/mem3/src/mem3_shards.erl
+++ b/src/mem3/src/mem3_shards.erl
@@ -724,42 +724,25 @@ spawn_link_mock_writer(Db, Shards, Timeout) ->
 
 
 mem3_shards_changes_test_() -> {
-    "Test mem3_shards changes listener", {
-        foreach,
-        fun setup_changes/0, fun teardown_changes/1,
+    "Test mem3_shards changes listener",
+    {
+        setup,
+        fun test_util:start_couch/0, fun test_util:stop_couch/1,
         [
-            fun should_kill_changes_listener_on_shutdown/1
+            fun should_kill_changes_listener_on_shutdown/0
         ]
     }
 }.
 
 
-setup_changes() ->
-    RespDb = test_util:fake_db([{name, <<"dbs">>}, {update_seq, 0}]),
-    ok = meck:expect(mem3_util, ensure_exists, ['_'], {ok, RespDb}),
-    ok = meck:expect(couch_db, close, ['_'], ok),
-    ok = application:start(config),
+should_kill_changes_listener_on_shutdown() ->
     {ok, Pid} = ?MODULE:start_link(),
+    {ok, ChangesPid} = get_changes_pid(),
+    ?assert(is_process_alive(ChangesPid)),
     true = erlang:unlink(Pid),
-    Pid.
-
-
-teardown_changes(Pid) ->
-    true = exit(Pid, shutdown),
-    ok = application:stop(config),
-    meck:unload().
-
-
-should_kill_changes_listener_on_shutdown(Pid) ->
-    ?_test(begin
-        ?assert(is_process_alive(Pid)),
-        {ok, ChangesPid} = get_changes_pid(),
-        ?assert(is_process_alive(ChangesPid)),
-        true = test_util:stop_sync_throw(
-            ChangesPid, fun() -> exit(Pid, shutdown) end, wait_timeout),
-        ?assertNot(is_process_alive(ChangesPid)),
-        ok
-    end).
-
+    true = test_util:stop_sync_throw(
+        ChangesPid, fun() -> exit(Pid, shutdown) end, wait_timeout),
+    ?assertNot(is_process_alive(ChangesPid)),
+    exit(Pid, shutdown).
 
 -endif.
diff --git a/src/mem3/test/01-config-default.ini b/src/mem3/test/01-config-default.ini
deleted file mode 100644
index dde92ce2d..000000000
--- a/src/mem3/test/01-config-default.ini
+++ /dev/null
@@ -1,14 +0,0 @@
-# Licensed under the Apache License, Version 2.0 (the "License"); you may not
-# use this file except in compliance with the License. You may obtain a copy of
-# the License at
-#
-#   http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations under
-# the License.
-
-[cluster]
-n=3
diff --git a/src/mem3/test/mem3_sync_security_test.erl b/src/mem3/test/mem3_sync_security_test.erl
index 8b6af3c0f..4e06dd807 100644
--- a/src/mem3/test/mem3_sync_security_test.erl
+++ b/src/mem3/test/mem3_sync_security_test.erl
@@ -19,11 +19,14 @@
 
 go_test() ->
     Ctx = test_util:start_couch([fabric, mem3]),
-    ok = meck:new(fabric, [passthrough]),
-    meck:expect(fabric, all_dbs, fun() ->
-        {ok, [<<"NoExistDb1">>, <<"NoExistDb2">>]}
-    end),
-    Result = mem3_sync_security:go(),
-    meck:unload(fabric),
-    test_util:stop_couch(Ctx),
-    ?assertEqual(ok, Result).
+    try
+        ok = meck:new(fabric, [passthrough]),
+        meck:expect(fabric, all_dbs, fun() ->
+            {ok, [<<"NoExistDb1">>, <<"NoExistDb2">>]}
+        end),
+        Result = mem3_sync_security:go(),
+        ?assertEqual(ok, Result)
+    after
+        meck:unload(),
+        test_util:stop_couch(Ctx)
+    end.
diff --git a/src/mem3/test/mem3_util_test.erl b/src/mem3/test/mem3_util_test.erl
index 163580cc2..214217ec4 100644
--- a/src/mem3/test/mem3_util_test.erl
+++ b/src/mem3/test/mem3_util_test.erl
@@ -121,47 +121,18 @@ build_shards_test() ->
 %% n_val tests
 
 nval_test_() ->
-    {"n_val tests explicit",
-     [
-      {setup,
-       fun () ->
-               meck:new([couch_log]),
-               meck:expect(couch_log, error, fun(_, _) -> ok end),
-               ok
-       end,
-       fun (_) -> meck:unload([couch_log]) end,
-       [
-        ?_assertEqual(2, mem3_util:n_val(2,4)),
-        ?_assertEqual(1, mem3_util:n_val(-1,4)),
-        ?_assertEqual(4, mem3_util:n_val(6,4))
+    {
+        setup,
+        fun() ->
+            meck:new([config, couch_log]),
+            meck:expect(couch_log, error, 2, ok),
+            meck:expect(config, get, 3, "5")
+        end,
+        fun(_) -> meck:unload() end,
+        [
+            ?_assertEqual(2, mem3_util:n_val(2, 4)),
+            ?_assertEqual(1, mem3_util:n_val(-1, 4)),
+            ?_assertEqual(4, mem3_util:n_val(6, 4)),
+            ?_assertEqual(5, mem3_util:n_val(undefined, 6))
         ]
-       }
-     ]
     }.
-
-
-config_01_setup() ->
-    Ini = filename:join([code:lib_dir(mem3, test), "01-config-default.ini"]),
-    {ok, Pid} = config:start_link([Ini]),
-    Pid.
-
-config_teardown(Pid) ->
-    test_util:stop_config(Pid).
-
-
-n_val_test_() ->
-    {"n_val tests with config",
-     [
-      {setup,
-       fun config_01_setup/0,
-       fun config_teardown/1,
-       fun(Pid) ->
-           {with, Pid, [
-               fun n_val_1/1
-            ]}
-       end}
-     ]
-    }.
-
-n_val_1(_Pid) ->
-    ?assertEqual(3, mem3_util:n_val(undefined, 4)).