[VOL-2235] Mocks and interfaces for rw-core

This update consists of mocks that are used by the rw-core
during unit testing.  It also includes interfaces used for unit
tests.

Change-Id: I20ca1455c358113c3aa897acc6355e0ddbc614b7
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto_errors.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto_errors.go
new file mode 100644
index 0000000..ca76324
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/proto_errors.go
@@ -0,0 +1,106 @@
+package runtime
+
+import (
+	"context"
+	"io"
+	"net/http"
+
+	"github.com/golang/protobuf/ptypes/any"
+	"github.com/grpc-ecosystem/grpc-gateway/internal"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/status"
+)
+
+// StreamErrorHandlerFunc accepts an error as a gRPC error generated via status package and translates it into a
+// a proto struct used to represent error at the end of a stream.
+type StreamErrorHandlerFunc func(context.Context, error) *StreamError
+
+// StreamError is the payload for the final message in a server stream in the event that the server returns an
+// error after a response message has already been sent.
+type StreamError internal.StreamError
+
+// ProtoErrorHandlerFunc handles the error as a gRPC error generated via status package and replies to the request.
+type ProtoErrorHandlerFunc func(context.Context, *ServeMux, Marshaler, http.ResponseWriter, *http.Request, error)
+
+var _ ProtoErrorHandlerFunc = DefaultHTTPProtoErrorHandler
+
+// DefaultHTTPProtoErrorHandler is an implementation of HTTPError.
+// If "err" is an error from gRPC system, the function replies with the status code mapped by HTTPStatusFromCode.
+// If otherwise, it replies with http.StatusInternalServerError.
+//
+// The response body returned by this function is a Status message marshaled by a Marshaler.
+//
+// Do not set this function to HTTPError variable directly, use WithProtoErrorHandler option instead.
+func DefaultHTTPProtoErrorHandler(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, _ *http.Request, err error) {
+	// return Internal when Marshal failed
+	const fallback = `{"code": 13, "message": "failed to marshal error message"}`
+
+	s, ok := status.FromError(err)
+	if !ok {
+		s = status.New(codes.Unknown, err.Error())
+	}
+
+	w.Header().Del("Trailer")
+
+	contentType := marshaler.ContentType()
+	// Check marshaler on run time in order to keep backwards compatability
+	// An interface param needs to be added to the ContentType() function on
+	// the Marshal interface to be able to remove this check
+	if httpBodyMarshaler, ok := marshaler.(*HTTPBodyMarshaler); ok {
+		pb := s.Proto()
+		contentType = httpBodyMarshaler.ContentTypeFromMessage(pb)
+	}
+	w.Header().Set("Content-Type", contentType)
+
+	buf, merr := marshaler.Marshal(s.Proto())
+	if merr != nil {
+		grpclog.Infof("Failed to marshal error message %q: %v", s.Proto(), merr)
+		w.WriteHeader(http.StatusInternalServerError)
+		if _, err := io.WriteString(w, fallback); err != nil {
+			grpclog.Infof("Failed to write response: %v", err)
+		}
+		return
+	}
+
+	md, ok := ServerMetadataFromContext(ctx)
+	if !ok {
+		grpclog.Infof("Failed to extract ServerMetadata from context")
+	}
+
+	handleForwardResponseServerMetadata(w, mux, md)
+	handleForwardResponseTrailerHeader(w, md)
+	st := HTTPStatusFromCode(s.Code())
+	w.WriteHeader(st)
+	if _, err := w.Write(buf); err != nil {
+		grpclog.Infof("Failed to write response: %v", err)
+	}
+
+	handleForwardResponseTrailer(w, md)
+}
+
+// DefaultHTTPStreamErrorHandler converts the given err into a *StreamError via
+// default logic.
+//
+// It extracts the gRPC status from err if possible. The fields of the status are
+// used to populate the returned StreamError, and the HTTP status code is derived
+// from the gRPC code via HTTPStatusFromCode. If the given err does not contain a
+// gRPC status, an "Unknown" gRPC code is used and "Internal Server Error" HTTP code.
+func DefaultHTTPStreamErrorHandler(_ context.Context, err error) *StreamError {
+	grpcCode := codes.Unknown
+	grpcMessage := err.Error()
+	var grpcDetails []*any.Any
+	if s, ok := status.FromError(err); ok {
+		grpcCode = s.Code()
+		grpcMessage = s.Message()
+		grpcDetails = s.Proto().GetDetails()
+	}
+	httpCode := HTTPStatusFromCode(grpcCode)
+	return &StreamError{
+		GrpcCode:   int32(grpcCode),
+		HttpCode:   int32(httpCode),
+		Message:    grpcMessage,
+		HttpStatus: http.StatusText(httpCode),
+		Details:    grpcDetails,
+	}
+}