Invalid code generated when package name contains uppercase letter

Summary

Title

Reproduction Steps

This protofile works:

// proto/test.proto
syntax = "proto3";

package p;

service Service {
  rpc Method(Empty) returns (Empty) {}
}

message Empty {}

This doesn't:

// proto/test.proto
syntax = "proto3";

package P;

service Service {
  rpc Method(Empty) returns (Empty) {}
}

message Empty {}

With the latter, betterproto compiles to this:

# Generated by the protocol buffer compiler.  DO NOT EDIT!
# sources: test.proto
# plugin: python-betterproto
# This file has been @generated

from dataclasses import dataclass
from typing import (
    TYPE_CHECKING,
    Dict,
    Optional,
)

import betterproto
import grpclib
from betterproto.grpc.grpclib_server import ServiceBase

from .. import PEmpty as _PEmpty__

# [...]

The from .. import PEmpty is invalid import as nothing exists in the parent package.

Command used:

python3 -m grpc_tools.protoc --proto_path=./proto/ --python_betterproto_out=./proto/ proto/*.proto

Python environment (output of pip freeze):

betterproto @ git+https://github.com/danielgtaylor/python-betterproto@5666393f9d10e13609d8eeac8d1ab3815dce5fd6
black==24.2.0
click==8.1.7
grpcio==1.62.1
grpcio-tools==1.62.1
grpclib==0.4.7
h2==4.1.0
hpack==4.0.0
hyperframe==6.0.1
isort==5.13.2
Jinja2==3.1.3
MarkupSafe==2.1.5
multidict==6.0.5
mypy-extensions==1.0.0
nodeenv==1.8.0
packaging==24.0
pathspec==0.12.1
platformdirs==4.2.0
protobuf==4.25.3
pyright==1.1.353
python-dateutil==2.9.0.post0
six==1.16.0
typing_extensions==4.10.0

Expected Results

Correct code generated

Actual Results

Incorrect code generated

System Information

libprotoc 3.12.4 Python 3.11.0rc1 Name: betterproto Version: 2.0.0b6 Summary: A better Protobuf / gRPC generator & library Home-page: https://github.com/danielgtaylor/python-betterproto Author: Daniel G. Taylor Author-email: danielgtaylor@gmail.com License: MIT Location: Requires: grpclib, python-dateutil, typing-extensions Required-by:

Checklist

[X] I have searched the issues for duplicates.
[X] I have shown the entire traceback, if possible.
[X] I have verified this issue occurs on the latest prelease of betterproto which can be installed using pip install -U --pre betterproto, if possible.

danielgtaylor / python-betterproto