proposal: x/tools/internal/jsonrpc2_v2: export wireError

[kortschak]

Proposal Details

This may not require a proposal since the package is internal. If a formal proposal is needed, I will flesh this out.

Problem

Currently the jsonrpc2.wireError does not provide access to the Data field within a handler. This makes it impossible for a handler to add data to a JSON RPC2.0 error in a way that will result in the caller receiving it due to the way that errors are handled by the response marshalling code path.

Proposal

I propose that the wireError type be exported. This will enable handlers to add values to the Data field and callers to be able to inspect the returned error data.

A less appealing alternative would be to add a new error creation function that adds the data field (additional API function surface) or alter the existing NewError (a relatively invasive and backward incompatible change, though note that the package is internal). Both of these changes would also require the addition an accessor for callers to be able to inspect the Data field.

Compatibility

The proposal is fully backward compatible because it exposes a previously unexported type. The package is currently internal.

Cost/Benefit

The package is currently internal and no internal user appears to have a need for this functionality. I make use of the package as a mechanically extracted non-internal package. If the proposal is rejected, I can work around this by making the change in the extracted package, but I'd like to see whether this is needed before I make that change.

[adonovan]

This doesn't need a proposal as it doesn't change the public API. Feel free to send us a CL and we can discuss it there.

[gopherbot]

Change https://go.dev/cl/562515 mentions this issue: internal/jsonrpc2: export WireError type

[gopherbot]

Change https://go.dev/cl/562575 mentions this issue: internal/jsonrpc2: export WireError type

[gopherbot]

Change https://go.dev/cl/562575 mentions this issue: internal/jsonrpc2_v2: export WireError type