Get a FieldDescriptor without hard-coding the field name (proto message)

Given the following proto message

message MyMsg {
  string my_field = 1;
  string your_field=2;
}

...the protoreflect package can be used to get a descriptor for each field

protoMessage := myMsg.ProtoReflect()
messageDescriptor := protoMessage.Descriptor() // protobuf type information
fieldDescriptors := messageDescriptor.Fields() // list of field declarations

Getting a field descriptor for a specific field is trivial

fieldDescriptor := fieldDescriptors.ByTextName("my_field") // describes a field

Can this be achieved without hard-coding the field name "my_field"? I guess it would be nice to use the generated code to refer to the field I'm interested in. Something like (not working code)

fieldDescriptor := fieldDescriptors.ByTextName(pb.MyMsg.MyField) // describes a field

This way, if the field name changes, it will be caught at compile time, or even from static analysis by an IDE.

The FieldDescriptors type has three methods for getting a field descriptor by name:

• ByName(s Name)
• ByJSONName(s string)
• ByTextName(s string)

ByJSONName and ByTextName both require hard-coded field names (as strings), and by ByName accepts a Name which is type'd to a string. The upshot is, I don't see anything in the protoreflect package that points to a solution.

Context

Field masks are the recommended way to support partial resource updates. It's trivial to iterate over the masks provided in a field mask

protoMessage := myMsg.ProtoReflect()
messageDescriptor := protoMessage.Descriptor() // protobuf type information
fieldDescriptors := messageDescriptor.Fields() // list of field declarations

// iterate over the field paths in the field mask
for _, p := range mask.GetPaths() {

	// find the field descriptor for the field path
	fieldDescriptor := fieldDescriptors.ByTextName(p)

	if fieldDescriptor == nil {
		// field descriptor cannot be found for the field path
		return
	}

	// great, the field path points to a field, let's use it

	switch p {
	case "my_field":
		// the client wants to update MyMsg.my_field

	case "your_field":
		// the client wants to update  MyMsg.your_field
	}
}

The problem is, in order to actually update the correct field in MyMsg, it's necessary to hard-code the field name in the switch statement.

The interface has ByNumber too

I assume (I've not used the method) that you could give this 1 from your example.

And Get, of course so that you can enumerate all of the FieldDescriptors.

I think it's not unreasonable to want to reflect (!) the generated (struct) types and enumerate across them but it feels like turtles-all-the-way-down.

It may help solicit other answers if you could present the problem that you're unable to solve without the desired method?