fix: handle badmap inside `emqx_placeholder:proc_tmpl`

apps/emqx_utils/src/emqx_placeholder.erl

@@ -277,20 +277,29 @@ lookup_var([Prop | Rest], Data0) ->
     end.
 
 lookup(Prop, Data) when is_binary(Prop) ->
-    case maps:get(Prop, Data, undefined) of
+    case do_one_lookup(Prop, Data) of
-        undefined ->
+        {error, undefined} ->
-            try
+            try binary_to_existing_atom(Prop, utf8) of
-                {ok, maps:get(binary_to_existing_atom(Prop, utf8), Data)}
+                AtomKey ->
+                    do_one_lookup(AtomKey, Data)
             catch
-                error:{badkey, _} ->
-                    {error, undefined};
                 error:badarg ->
                     {error, undefined}
             end;
-        Value ->
+        {ok, Value} ->
             {ok, Value}
     end.
 
+do_one_lookup(Key, Data) ->
+    try
+        {ok, maps:get(Key, Data)}
+    catch
+        error:{badkey, _} ->
+            {error, undefined};
+        error:{badmap, _} ->
+            {error, undefined}
+    end.
+
 %%------------------------------------------------------------------------------
 %% Internal functions
 %%------------------------------------------------------------------------------

apps/emqx_utils/src/emqx_utils.app.src

@@ -2,7 +2,7 @@
 {application, emqx_utils, [
     {description, "Miscellaneous utilities for EMQX apps"},
     % strict semver, bump manually!
-    {vsn, "5.0.7"},
+    {vsn, "5.0.8"},
     {modules, [
         emqx_utils,
         emqx_utils_api,

apps/emqx_utils/test/emqx_placeholder_SUITE.erl

@@ -256,3 +256,25 @@ t_proc_tmpl_arbitrary_var_name_double_quote(_) ->
         <<"a:1,a:1-1,b:1,b:2,c:1.0,d:oo,d1:hi}">>,
         emqx_placeholder:proc_tmpl(Tks, Selected)
     ).
+
+t_proc_tmpl_badmap(_Config) ->
+    ThisTks = emqx_placeholder:preproc_tmpl(<<"${.}">>),
+    Tks = emqx_placeholder:preproc_tmpl(<<"${.a.b.c}">>),
+    BadMap = <<"not-a-map">>,
+    ?assertEqual(
+        <<"not-a-map">>,
+        emqx_placeholder:proc_tmpl(ThisTks, BadMap)
+    ),
+    ?assertEqual(
+        <<"undefined">>,
+        emqx_placeholder:proc_tmpl(Tks, #{<<"a">> => #{<<"b">> => BadMap}})
+    ),
+    ?assertEqual(
+        <<"undefined">>,
+        emqx_placeholder:proc_tmpl(Tks, #{<<"a">> => BadMap})
+    ),
+    ?assertEqual(
+        <<"undefined">>,
+        emqx_placeholder:proc_tmpl(Tks, BadMap)
+    ),
+    ok.