The 'result' key MUST be unset according when the error key is set.
This is not what is happening right now. When the error is set,
"result":null is returned in the response payload. This patch is fixing
the issue by adding omitempty for the result field.
NOTE: This is a breaking change to the expected contract of Handler. Please update your implementation to use AsyncHandler if needs be.
We have strict ordering requirements of how we handle FileSystem requests in
LSP. As such relying on the ordering the goroutine scheduler runs requests in
leads to potential out of order mutations to the FS. As such we update the
jsonrpc2 implementation to by default block until Handle returns (note it can
still respond to the request at a later stage). For more simple use cases we
provide the AsyncHandler which will work like the previous implementation.
* Ensure handle is blocking
Running various applications that use jsonrpc2 with the Go race detector shows that there is a race condition where `WriteObject` can be called from concurrent goroutines (e.g., 1 sending a request, 1 writing a response).
This makes the MarshalJSON/UnmarshalJSON methods centralize the logic, instead of requiring callers to occasionally munge responses to make them valid to later JSON-marshal.
Previously, we incorrectly interpreted these as neither a request nor a response, and we printed an error for them. This is incorrect behavior per JSON-RPC 2.0 spec; responses can have a null result.
simplify API by using interface{}, rename from transport -> stream
add WebSocket transport in websocket subpackage
do not buffer in ReadObject, rename GetObjectReader/ReadObject -> NextObjectReader
use xtest (jsonrpc2_test) package to allow us to test subpackages that depend on us (in a future change)
factor out vscode-specific transport code and allow pluggable transports
remove Server (unused) and Serve (unnecessary):
The Serve func had nothing specific to JSON-RPC; it was just a loop
around (net.Listener).Accept. It added no value.
Audited all calls for Printf. Noticed the following in some logs
```
jsonrpc2 handler: sending response {1 %!d(string=) %!d(bool=false)}: jsonrpc2: connection is closed
```
I accidentally made this change in the main repo, instead of here.
This ensures that the server can tell the difference between a response and a request. The old method (resp == nil) didn't work because we use interfaces here, and the interfaces would often have types, but not values.
