Remove `grpc` dependency

[mic-max]

Hard code the NOT_FOUND status code from the grpc library (deprecated).

The enum grpc.status has not been changed in 5 years from viewing the git blame and IMO likely won't. Further, when people download this package from NPM they could see a warning in the console saying that a package has been deprecated since grpc-health-check relies on grpc.

---

Actually, can't fully remove the grpc dependency from the package.json since the https://github.com/grpc/grpc-node/blob/master/packages/grpc-health-check/v1/health_grpc_pb.js uses it for the makeGenericClientConstructor function - which doesn't look like it would be a simple copy to this repository if that would even be desirable.

[murgatroid99]

This is something I've been meaning to address for a while but I haven't had the chance. I think the right way to do this is to entirely remove the grpc dependency by removing the Client export. However, this has knock-on effects. The service export also comes from health_grpc_pb.js, and we want to keep the service export. So, I think the simplest solution is to switch protobuf implementations to @grpc/proto-loader, which would require rewriting some of the implementation code. That would also result in removing the messages export.

[mic-max]

This is something I've been meaning to address for a while but I haven't had the chance. I think the right way to do this is to entirely remove the grpc dependency by removing the Client export. However, this has knock-on effects. The service export also comes from health_grpc_pb.js, and we want to keep the service export. So, I think the simplest solution is to switch protobuf implementations to @grpc/proto-loader, which would require rewriting some of the implementation code. That would also result in removing the messages export.

Removing the Client export would require a major version bump I guess right? It's not something that my program uses at all so I'd be fine with that change 😅

switch protobuf implementations to @grpc/proto-loader

Would this mean the ./v1/ directory be deleted and the .proto parsing and code generation would be done at application startup? Also, how would I test/compile this project - I might work on this improvement and would want the next PR update to be working - this one I just did by hand on GitHub.com 😅

[murgatroid99]

Removing the Client export would require a major version bump I guess right? It's not something that my program uses at all so I'd be fine with that change 😅

Yes, the change I suggest would need to be a major version bump. Practically speaking, it's just one line in either gRPC implementation to create the Client class from the service.

Would this mean the ./v1/ directory be deleted and the .proto parsing and code generation would be done at application startup?

Yes, that's what I would do.

Also, how would I test/compile this project - I might work on this improvement and would want the next PR update to be working - this one I just did by hand on GitHub.com 😅

The existing test setup will also have to be updated to handle not having the grpc dependency. I would add a dev dependency "@grpc/grpc-js": "../grpc-js" and change the import. The test code also uses proto messages, so that code will also need to be updated to handle the new code generation.