Expose trailingMetadata
Closed this issue · 7 comments
Support for GRPCStatusAndMetadata - https://github.com/grpc/grpc-swift/blob/main/Sources/GRPC/GRPCStatusAndMetadata.swift would be awesome.
Currently on GRPCStatus is exposed - https://github.com/vyshane/grpc-swift-combine/blob/master/Sources/CombineGRPC/Client/GRPCExecutor.swift#L93
Do you need access to the trailing metadata only on failure, or do you also need it on success?
On error @vyshane — The Go backend adds additional error details when an error occurs - I’m trying do get them using the method described here - grpc/grpc-swift#759 (comment)
Okay, if we're only talking about supporting trailing metadata for the error use case, then the call APIs can be changed to:
| RPC Style | Input and Output Types |
|---|---|
| Unary | Request -> AnyPublisher<Response, GRPCError> |
| Server streaming | Request -> AnyPublisher<Response, GRPCError> |
| Client streaming | AnyPublisher<Request, Error> -> AnyPublisher<Response, GRPCError> |
| Bidirectional streaming | AnyPublisher<Request, Error> -> AnyPublisher<Response, GRPCError> |
Where the new GRPCError type is a struct with status and trailingMetadata fields. We can't use the upstream GRPCStatusAndMetadata type because it does not extend Error.
This will be a major breaking change for all call methods.
Cool - this would make the library even more transparent 😉 - looking forward to this addition
I have just merged a PR that adds trailing metadata support to client calls and server handlers. I called the wrapper type RPCError. Swift gRPC already has a type called GRPCError. Can you give master branch a go and let me know if that works for your use case?
This introduced breaking API changes for call and handle functions, as well as RetryPolicy.