Crash compiling Yojson use of empty messages
Closed this issue · 3 comments
vphantom commented
Hi! Thank you for your work. 😄 When compiling the use of an empty message, i.e.:
message Empty {} // This line is fine
message Test {
Empty empty = 1; // This crashes
}…I get a crash in Yojson mode:
$ ocaml-protoc -binary -yojson -ml_out . test.proto
Generating ./test_types.mli
Generating ./test_types.ml
File "src/compilerlib/pb_codegen_decode_yojson.ml", line 31, characters 18-24: Assertion failed
Indeed, that's https://github.com/mransan/ocaml-protoc/blob/master/src/compilerlib/pb_codegen_decode_yojson.ml#L31
I know that the JSON representation should be an empty object (i.e. `Assoc []) but not to the point of knowing how to contribute this. 😕
Lupus commented
message Empty {} also seems to omit the type from generated files with types, so support for empty protobuf messages is not really present in the library...
c-cube commented
If I remember correctly, such empty messages become `unit` when compiled. For json it's probably a bug, and a PR would be very helpful.