khepri_machine: Use initial tree to list sprocs triggered by deletions

src/khepri_machine.erl

@@ -2253,9 +2253,10 @@ add_trigger_side_effects(InitialState, NewState, Changes, SideEffects) ->
         false ->
             EmittedTriggers = get_emitted_triggers(InitialState),
             #config{store_id = StoreId} = get_config(NewState),
-            Tree = get_tree(NewState),
+            InitialTree = get_tree(InitialState),
+            NewTree = get_tree(NewState),
             TriggeredStoredProcs = list_triggered_sprocs(
-                                     Tree, Changes, Triggers),
+                                     InitialTree, NewTree, Changes, Triggers),
 
             %% We record the list of triggered stored procedures in the state
             %% machine's state. This is used to guaranty at-least-once
@@ -2278,11 +2279,17 @@ add_trigger_side_effects(InitialState, NewState, Changes, SideEffects) ->
             {NewState1, [SideEffect | SideEffects]}
     end.
 
-list_triggered_sprocs(Tree, Changes, Triggers) ->
+list_triggered_sprocs(InitialTree, NewTree, Changes, Triggers) ->
     TriggeredStoredProcs =
     maps:fold(
       fun(Path, Change, TSP) ->
               % For each change, we evaluate each trigger.
+              Tree = case Change of
+                         delete ->
+                             InitialTree;
+                         _ ->
+                             NewTree
+                     end,
               maps:fold(
                 fun(TriggerId, TriggerProps, TSP1) ->
                         evaluate_trigger(

test/triggers.erl

@@ -442,6 +442,59 @@ filter_on_change_type_test_() ->
          ?_assertEqual(executed, receive_sproc_msg(DeletedKey))}]
       }]}.
 
+filter_on_pattern_test_() ->
+    Path = [foo, bar],
+    EventFilter = khepri_evf:tree([foo, #if_has_data{}]),
+    StoredProcPath = [sproc],
+    Key = ?FUNCTION_NAME,
+    {setup,
+     fun() -> test_ra_server_helpers:setup(?FUNCTION_NAME) end,
+     fun(Priv) -> test_ra_server_helpers:cleanup(Priv) end,
+     [{inorder,
+       [{"Storing a procedure",
+         ?_assertMatch(
+            ok,
+            khepri:put(
+              ?FUNCTION_NAME, StoredProcPath,
+              make_sproc(self(), Key)))},
+
+        {"Registering a trigger",
+         ?_assertEqual(
+            ok,
+            khepri:register_trigger(
+              ?FUNCTION_NAME,
+              ?FUNCTION_NAME,
+              EventFilter,
+              StoredProcPath))},
+
+        {"Creating a node; should trigger the procedure",
+         ?_assertMatch(
+            ok,
+            khepri:put(
+              ?FUNCTION_NAME, Path, value1))},
+
+        {"Checking the procedure was executed on create",
+         ?_assertEqual(executed, receive_sproc_msg(?FUNCTION_NAME))},
+
+        {"Updating a node; should trigger the procedure",
+         ?_assertMatch(
+            ok,
+            khepri:put(
+              ?FUNCTION_NAME, Path, value2))},
+
+        {"Checking the procedure was executed on update",
+         ?_assertEqual(executed, receive_sproc_msg(?FUNCTION_NAME))},
+
+        {"Deleting a node; should trigger the procedure",
+         ?_assertMatch(
+            ok,
+            khepri:delete(
+              ?FUNCTION_NAME, Path))},
+
+        {"Checking the procedure was executed on delete",
+         ?_assertEqual(executed, receive_sproc_msg(?FUNCTION_NAME))}]
+      }]}.
+
 a_buggy_sproc_does_not_crash_state_machine_test_() ->
     EventFilter = khepri_evf:tree([foo]),
     StoredProcPath = [sproc],