No blockers, but I have some questions

Reviewed 9 of 9 files at r1, all commit messages.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @coryan)

google/cloud/storage/internal/grpc_client.cc, line 270 at r1 (raw file):

  // extra prefix to ApplyQueryParameters sends the right filtering instructions
  // to the gRPC API.
  ApplyQueryParameters(*context, request, "resource");

I guess I don't understand why this is the only call that has the "resource" prefix.

e.g. the proto for QueryWriteStatusResponse has an Object resource.

google/cloud/storage/internal/grpc_configure_client_context.h, line 39 at r1 (raw file):

template <typename Request>
void ApplyQueryParameters(grpc::ClientContext& context, Request const& request,
                          std::string const& prefix = std::string{}) {

is the prefix ever anything other than "" or "resource"? Not saying we should, but it could be something like bool use_resource = false

google/cloud/storage/internal/grpc_configure_client_context.h, line 57 at r1 (raw file):

  if (request.template HasOption<Fields>()) {
    auto field_mask = request.template GetOption<Fields>().value();
    if (!prefix.empty()) field_mask = prefix + "(" + field_mask + ")";

This looks nicer, but absl::StrCat() is possible.

google/cloud/storage/internal/grpc_configure_client_context_test.cc, line 1 at r1 (raw file):

// Copyright 2019 Google LLC

2021

PTAL.

Reviewable status: 5 of 10 files reviewed, all discussions resolved (waiting on @dbolduc)

google/cloud/storage/internal/grpc_client.cc, line 270 at r1 (raw file):

Good question, fixed here and elsewhere. Actually I had to create a few additional PRs to fix this for REST too.

google/cloud/storage/internal/grpc_configure_client_context.h, line 39 at r1 (raw file):

For now that is it, but I expect that might change as we implement more APIs over gRPC.

google/cloud/storage/internal/grpc_configure_client_context.h, line 57 at r1 (raw file):

I am leaving as-is, it is readable enough for me.

google/cloud/storage/internal/grpc_configure_client_context_test.cc, line 1 at r1 (raw file):

Fixed.