import DescriptorProto custom option extensions with "import"

[dvisztempacct]

When importing a package with import you can access custom options that are defined therein by namespacing the option with the package name of the imported .proto file where said custom options were are defined.

For example, this works:

extend.proto:

syntax = "proto3";
package tin_extend;
/* boilerplate needed for TIN sanitization/validation/normalization */
import "google/protobuf/descriptor.proto";
extend google.protobuf.FileOptions {
  string tin_module_validation = 4000;
}
extend google.protobuf.MessageOptions {
  string tin_message_validation = 4000;
}
extend google.protobuf.FieldOptions {
  string tin_field_validation = 4000;
}

assemblyline.proto:

syntax = "proto3";
package assemblyline;
import "extend.proto";

/* Our proto stuff */

enum WidgetCondition {
  WIDGET_CONDITION_ADEQUATE = 0;
  WIDGET_CONDITION_DEFECTIVE = 1;
}

enum WidgetColor {
  WIDGET_COLOR_UNPAINTED = 0;
  WIDGET_COLOR_RED = 1;
  WIDGET_COLOR_GREEN = 2;
}

message BlankWidget {
  WidgetCondition condition = 1 [
    (tin_extend.tin_field_validation) = "required"
  ];
}

message CutWidget {
  WidgetCondition condition = 1 [
    (tin_extend.tin_field_validation) = "required"
  ];
  int32 numTeeth = 2 [
    (tin_extend.tin_field_validation) = "required |> numberRange(32, 63)"
  ];
}

message PaintedWidget {
  WidgetCondition condition = 1[
    (tin_extend.tin_field_validation) = "required"
  ];
  int32 numTeeth = 2[
    (tin_extend.tin_field_validation) = "required |> numberRange(32, 63)"
  ];
  WidgetColor paintJob = 3[
    (tin_extend.tin_field_validation) = "required"
  ];
}

message BoxOfWidgets {
  repeated PaintedWidget paintedWidgets = 1;
}