are all errors returned by gRPC wrapped by status.Status?

[xiang90]

Can I assume that all errors returned by gRPC are https://godoc.org/google.golang.org/grpc/status#Status type?

If so, why ErrClientConnClosing is public? And there are other error types defined in https://godoc.org/google.golang.org/grpc/transport.

[xiang90]

/cc @gyuho

[gyuho]

Note: currently we are using grpc v1.6.0. And plan to upgrade to v.1.7.0.

[menghanl]

Status is to represent RPC status (the error code, message and details).
All errors returned by RPCs should be type Status.

Errors returned by other function like Dial are not type Status.

[xiang90]

@menghanl

Great! That matches my expectation.

Can we document this somewhere? (Or if this is already documented, can you point me to the doc?)

[menghanl]

It's not explicitly documented now.
In the doc for status package, there's this line that conveys the same message:

gRPC service handlers should return an error created by this package, and 
gRPC clients should expect a corresponding error to be returned from the RPC call

We will see if there's a better place to document this behavior.