From e15c0c325e3d4c742b99e8169a07977e9ac70ed0 Mon Sep 17 00:00:00 2001
From: Shawn <506895667@qq.com>
Date: Fri, 18 Dec 2020 18:19:35 +0800
Subject: [PATCH] fix(rule_engine): nested_get value from binary was supported
 in 4.1

---
 apps/emqx_rule_engine/src/emqx_rule_maps.erl    | 17 ++++++++---------
 .../test/emqx_rule_engine_SUITE.erl             | 14 +++++++++++++-
 .../test/emqx_rule_maps_SUITE.erl               |  5 +++++
 3 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/apps/emqx_rule_engine/src/emqx_rule_maps.erl b/apps/emqx_rule_engine/src/emqx_rule_maps.erl
index 7ccd16c0c..e826d108b 100644
--- a/apps/emqx_rule_engine/src/emqx_rule_maps.erl
+++ b/apps/emqx_rule_engine/src/emqx_rule_maps.erl
@@ -30,15 +30,8 @@ nested_get(Key, Data) ->
 
 nested_get({var, Key}, Data, Default) ->
     general_map_get({key, Key}, Data, Data, Default);
-nested_get({path, Path}, Data, Default) when is_map(Data) orelse is_list(Data),
-                                             is_list(Path) ->
-    do_nested_get(Path, Data, Data, Default);
-nested_get(Key, Data, Default) when not is_map(Data) ->
-    try emqx_json:decode(Data, [return_maps]) of
-        Json -> nested_get(Key, Json, Default)
-    catch
-        _:_ -> Default
-    end.
+nested_get({path, Path}, Data, Default) when is_list(Path) ->
+    do_nested_get(Path, Data, Data, Default).
 
 do_nested_get([Key|More], Data, OrgData, Default) ->
     case general_map_get(Key, Data, OrgData, undefined) of
@@ -81,6 +74,12 @@ general_map_put(Key, Val, Map, OrgData) ->
             (_) -> do_put(Key, Val, Map, OrgData)
         end).
 
+general_find(KeyOrIndex, Data, OrgData, Handler) when is_binary(Data) ->
+    try emqx_json:decode(Data, [return_maps]) of
+        Json -> general_find(KeyOrIndex, Json, OrgData, Handler)
+    catch
+        _:_ -> Handler(not_found)
+    end;
 general_find({key, Key}, Map, _OrgData, Handler) when is_map(Map) ->
     case maps:find(Key, Map) of
         {ok, Val} -> Handler({found, {{key, Key}, Val}});
diff --git a/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl b/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl
index 99a89ac32..49b1d2ea1 100644
--- a/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl
+++ b/apps/emqx_rule_engine/test/emqx_rule_engine_SUITE.erl
@@ -125,7 +125,8 @@ groups() ->
       [t_events
       ]},
      {bugs, [],
-      [t_sqlparse_payload_as
+      [t_sqlparse_payload_as,
+       t_sqlparse_nested_get
       ]},
      {multi_actions, [],
       [t_sqlselect_multi_actoins_1,
@@ -2008,6 +2009,17 @@ t_sqlparse_payload_as(_Config) ->
         }
     }, Res02).
 
+t_sqlparse_nested_get(_Config) ->
+    Sql = "select payload as p, p.a.b as c "
+          "from \"t/#\" ",
+    ?assertMatch({ok,#{<<"c">> := 0}},
+        emqx_rule_sqltester:test(
+        #{<<"rawsql">> => Sql,
+          <<"ctx">> => #{
+              <<"topic">> => <<"t/1">>,
+              <<"payload">> => <<"{\"a\": {\"b\": 0}}">>
+          }})).
+
 %%------------------------------------------------------------------------------
 %% Internal helpers
 %%------------------------------------------------------------------------------
diff --git a/apps/emqx_rule_engine/test/emqx_rule_maps_SUITE.erl b/apps/emqx_rule_engine/test/emqx_rule_maps_SUITE.erl
index 2a7ccb9f6..3d4adb364 100644
--- a/apps/emqx_rule_engine/test/emqx_rule_maps_SUITE.erl
+++ b/apps/emqx_rule_engine/test/emqx_rule_maps_SUITE.erl
@@ -101,6 +101,11 @@ t_nested_get_map(_) ->
     ?assertEqual(v1, nested_get(?path([<<"p">>,<<"x">>]), #{p => #{x => v1}})),
     ?assertEqual(c, nested_get(?path([a,b,c]), #{a => #{b => #{c => c}}})).
 
+t_nested_get_map_1(_) ->
+    ?assertEqual(1, nested_get(?path([a]), <<"{\"a\": 1}">>)),
+    ?assertEqual(<<"{\"b\": 1}">>, nested_get(?path([a]), #{a => <<"{\"b\": 1}">>})),
+    ?assertEqual(1, nested_get(?path([a,b]), #{a => <<"{\"b\": 1}">>})).
+
 t_nested_get_index(_) ->
     %% single index get
     ?assertEqual(1, nested_get(?path([{ic,1}]), [1,2,3])),