fix: rule engine different behavior for div and mod

Previously, the div operation could only be used as an infix operation
while mod could only be used as a function call. After this commit, one
can use both div and mod using function call syntax and infix syntax.

Fixes: https://emqx.atlassian.net/browse/EMQX-10216

apps/emqx_rule_engine/include/rule_engine.hrl

@@ -149,7 +149,8 @@
                        Op =:= '-' orelse
                        Op =:= '*' orelse
                        Op =:= '/' orelse
-                       Op =:= 'div')).
+                       Op =:= 'div' orelse
+                       Op =:= 'mod')).
 
 %% Compare operators
 -define(is_comp(Op), (Op =:= '=' orelse

apps/emqx_rule_engine/test/emqx_rulesql_SUITE.erl

@@ -57,6 +57,7 @@ groups() ->
       , t_sqlselect_00
       , t_sqlselect_01
       , t_sqlselect_02
+      , t_sqlselect_04
       , t_sqlselect_1
       , t_sqlselect_2
       ]},
@@ -423,6 +424,39 @@ t_sqlselect_03(_Config) ->
     emqtt:stop(Client),
     emqx_rule_registry:remove_rule(TopicRule1).
 
+t_sqlselect_04(_Config) ->
+    %% Verify that div and mod works as expected
+    ok = emqx_rule_engine:load_providers(),
+    SQL = ""
+        "select 2 mod 2   as mod1,\n"
+        "       mod(3, 2) as mod2,\n"
+        "       4 div 2   as div1,\n"
+        "       div(7, 2) as div2\n"
+        "from \"t2\" "
+        "",
+    TopicRule1 = create_simple_repub_rule(
+                    <<"t1">>,
+                    SQL,
+                    <<"{\"mod1\": ${mod1},\"mod2\": ${mod2},\"div1\": ${div1},\"div2\": ${div2}}">>
+        ),
+    {ok, Client} = emqtt:start_link([{username, <<"emqx">>}]),
+    {ok, _} = emqtt:connect(Client),
+    {ok, _, _} = emqtt:subscribe(Client, <<"t1">>, 0),
+    emqtt:publish(Client, <<"t2">>, <<"">>, 0),
+    receive {publish, #{payload := Payload}} ->
+        ?assertMatch(#{
+            <<"mod1">> := 0,
+            <<"mod2">> := 1,
+            <<"div1">> := 2,
+            <<"div2">> := 3
+        }, emqx_json:decode(Payload, [return_maps]))
+    after 1000 ->
+        ct:fail(wait_for_t1)
+    end,
+    emqtt:stop(Client),
+    emqx_rule_registry:remove_rule(TopicRule1).
+
+
 t_sqlselect_1(_Config) ->
     ok = emqx_rule_engine:load_providers(),
     TopicRule = create_simple_repub_rule(

changes/v4.4.19-en.md

@@ -46,3 +46,5 @@
 - Fixed an issue where the WebHook plugin failed to execute the `on_client_connack` hook [#10710](https://github.com/emqx/emqx/pull/10710).
 
   See https://github.com/emqx/emqx/issues/10628 for more details.
+
+- Addressed an inconsistency in the usage of 'div' and 'mod' operations within the rule engine. Previously, the 'div' operation was only usable as an infix operation and 'mod' could only be applied through a function call. With this change, both 'div' and 'mod' can be used via function call syntax and infix syntax.

rebar.config

@@ -57,7 +57,7 @@
     , {replayq, {git, "https://github.com/emqx/replayq", {tag, "0.3.5"}}}
     , {pbkdf2, {git, "https://github.com/emqx/erlang-pbkdf2.git", {branch, "2.0.4"}}}
     , {emqtt, {git, "https://github.com/emqx/emqtt", {tag, "1.2.3.2"}}}
-    , {rulesql, {git, "https://github.com/emqx/rulesql", {tag, "0.1.5"}}}
+    , {rulesql, {git, "https://github.com/emqx/rulesql", {tag, "0.1.7"}}}
     , {recon, {git, "https://github.com/ferd/recon", {tag, "2.5.1"}}}
     , {observer_cli, "1.6.1"} % NOTE: depends on recon 2.5.1
     , {getopt, "1.0.1"}