Merge pull request #13147 from kjellwinblad/kjell/fix_function_clause_when_decoding_protobuf/EMQX-12453

fix: make protobuf schema decode error reported to user less cryptic

apps/emqx_schema_registry/src/emqx_schema_registry.app.src

@@ -1,6 +1,6 @@
 {application, emqx_schema_registry, [
     {description, "EMQX Schema Registry"},
-    {vsn, "0.3.0"},
+    {vsn, "0.3.1"},
     {registered, [emqx_schema_registry_sup]},
     {mod, {emqx_schema_registry_app, []}},
     {included_applications, [

apps/emqx_schema_registry/src/emqx_schema_registry_serde.erl

@@ -64,7 +64,21 @@ handle_rule_function(sparkplug_encode, [Term | MoreArgs]) ->
         [?EMQX_SCHEMA_REGISTRY_SPARKPLUGB_SCHEMA_NAME, Term | MoreArgs]
     );
 handle_rule_function(schema_decode, [SchemaId, Data | MoreArgs]) ->
-    decode(SchemaId, Data, MoreArgs);
+    try
+        decode(SchemaId, Data, MoreArgs)
+    catch
+        error:{gpb_error, {decoding_failure, {_Data, _Schema, {error, function_clause, _Stack}}}} ->
+            throw(
+                {schema_decode_error, #{
+                    error_type => decoding_failure,
+                    schema_id => SchemaId,
+                    data => Data,
+                    more_args => MoreArgs,
+                    explain =>
+                        <<"The given data could not be decoded. Please check the input data and the schema.">>
+                }}
+            )
+    end;
 handle_rule_function(schema_decode, Args) ->
     error({args_count_error, {schema_decode, Args}});
 handle_rule_function(schema_encode, [SchemaId, Term | MoreArgs]) ->

apps/emqx_schema_registry/test/emqx_schema_registry_SUITE.erl

@@ -44,7 +44,8 @@ sparkplug_tests() ->
         t_sparkplug_decode,
         t_sparkplug_encode,
         t_sparkplug_decode_encode_with_message_name,
-        t_sparkplug_encode_float_to_uint64_key
+        t_sparkplug_encode_float_to_uint64_key,
+        t_decode_fail
     ].
 
 init_per_suite(Config) ->
@@ -532,6 +533,23 @@ t_encode(Config) ->
     end,
     ok.
 
+t_decode_fail(_Config) ->
+    SerdeName = my_serde,
+    SerdeType = protobuf,
+    ok = create_serde(SerdeType, SerdeName),
+    Payload = <<"ss">>,
+    ?assertThrow(
+        {schema_decode_error, #{
+            data := <<"ss">>,
+            error_type := decoding_failure,
+            explain := _,
+            more_args := [<<"Person">>],
+            schema_id := <<"my_serde">>
+        }},
+        emqx_rule_funcs:schema_decode(<<"my_serde">>, Payload, <<"Person">>)
+    ),
+    ok.
+
 t_decode(Config) ->
     SerdeType = ?config(serde_type, Config),
     SerdeName = my_serde,

changes/ee/fix-13147.en.md

@@ -0,0 +1 @@
+Error messages for decoding failures in the rule engine protobuf decode functions have been improved by adding a clear descriptions to indicate what went wrong when message decoding fails.