send exception message instead of "Server error"

[BlackZork]

When RPC methods raises an exception there is always the same reply returned:

INFO jsonrpcclient.client.response: {"jsonrpc": "2.0", "error": {"code": -32000, "message": "Server error"}, "id": 2}

It would be great if 'message' could contain str(exception) that was thrown by called method.

[bcb]

You can pass debug=True to dispatch to include more info in the response message.

[BlackZork]

Is it ok to use debug=True in production code?

[bcb]

Generally you wouldn't want the client seeing your exception messages, for security reasons, but it depends on your situation.

[BlackZork]

I could decorate my rpc methods, catch exceptions and send my own messages like { result: False, data: }, but this is creating a protocol inside protocol.

You are right that passing str(exception) as message is not a good idea, but maybe jsonrpcserver should have a way to provide error message from client code when exception is raised.
For me it would be great if I could register my own exception handler that will return a string that will be later sent in json reply.

[bcb]

We could give the option to disable exception handling, so the user could handle them

try:
    response = dispatch(request, handle_exceptions=False)
except Exception exc:
    response = ExceptionResponse(str(exc))

[seidlmic]

As I am looking in code, is it true that before ver. 4.0 I can not easily implement my own exceptions with application specific return codes. In other words I have to use protocol inside protocol mentioned above? Am I right? Is there plan to update 3.x version.

[bcb]

Yes we can update the 3.x version if needed.

Can you show me what the response message would look like?

[seidlmic]

I would like to implement application defined errors with specific code, message and data (https://www.jsonrpc.org/specification#response_object). So something like
{"jsonrpc": "2.0", "error": {"code": -32800, "message": "Invalid input geometry", "data": {"index": 33, "coordinates": [1135.124, -25689]}}, "id": "1"}
I would like to raise application defined exception in rpc method that I would handle in the way shown above. I am working with geo data that are not always perfect.

[okke-formsma]

I have the same issue as @seidlmic.

One approach would be to raise a ExceptionResponse from inside the method. This way, all 'specially handled' exceptions will get the proper response, and 'normal' exceptions get the generic jsonrpc exception handling.

To make this happen, we only have to adjust the handle_exceptions call to catch ExceptionResponses and rethrow them.

Also could you reopen this issue? It took me a while to find this.

[ixje]

Same! Was about to open an issue to request this feature. It's the only reason I had to pass on from using this (for now). The rest looked really convenient to use.

I like the idea of @okke-formsma as that keeps the custom exception formatting close to the source

[st31ny]

Is there already work in progress on this matter? If not, I'd like to volunteer as I am also really interested in this feature.