From a5045390974b5efd913f3568a35fc607ee3fc1ee Mon Sep 17 00:00:00 2001
From: Zaiming Shi <zmstone@gmail.com>
Date: Tue, 10 Nov 2020 16:38:01 +0100
Subject: [PATCH] fix(emqx_rule_registry): Dialyzer warning

---
 apps/emqx_rule_engine/src/emqx_rule_metrics.erl  |  2 +-
 apps/emqx_rule_engine/src/emqx_rule_registry.erl | 11 ++++++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/apps/emqx_rule_engine/src/emqx_rule_metrics.erl b/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
index c24954f94..48058eed2 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_metrics.erl
@@ -99,7 +99,7 @@
 
 -record(state, {
             metric_ids = sets:new(),
-            rule_speeds :: #{rule_id() => #rule_speed{}},
+            rule_speeds :: undefined | #{rule_id() => #rule_speed{}},
             overall_rule_speed :: #rule_speed{}
         }).
 
diff --git a/apps/emqx_rule_engine/src/emqx_rule_registry.erl b/apps/emqx_rule_engine/src/emqx_rule_registry.erl
index 9681f8daa..395e13eff 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_registry.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_registry.erl
@@ -166,6 +166,10 @@ start_link() ->
 get_rules() ->
     get_all_records(?RULE_TAB).
 
+%% TODO: emqx_rule_utils:can_topic_match_oneof(Topic::any(), For::atom())
+%% will never return since it differs in the 2nd argument from the success
+%% typing arguments: (any(), [binary() | ['' | '#' | '+' | binary()]])
+-dialyzer([{nowarn_function, get_rules_for/1}]).
 -spec(get_rules_for(Topic :: binary()) -> list(emqx_rule_engine:rule())).
 get_rules_for(Topic) ->
     [Rule || Rule = #rule{for = For} <- get_rules(),
@@ -329,9 +333,10 @@ remove_resource_params(ResId) ->
 
 %% @private
 delete_resource(ResId) ->
-    [[ResId =:= ResId1 andalso throw({dependency_exists, {rule, Id}})
-        || #action_instance{args = #{<<"$resource">> := ResId1}} <- Actions]
-            || #rule{id = Id, actions = Actions} <- get_rules()],
+    %% TODO, change to foreache:s
+    _ = [[ResId =:= ResId1 andalso throw({dependency_exists, {rule, Id}})
+            || #action_instance{args = #{<<"$resource">> := ResId1}} <- Actions]
+                || #rule{id = Id, actions = Actions} <- get_rules()],
     mnesia:delete(?RES_TAB, ResId, write).
 
 %% @private