lusis / twirp-gen-csharp

Protobuf client code generators for Twirp services (https://github.com/twitchtv/twirp)

twirp-gen

Simple Protobuf code generators specifically for Twirp services.

This exists because other code generators either required external dependencies or were too complex for my needs.

Installing

# For JavaScript generation
go install github.com/seanpfeifer/twirp-gen/cmd/protoc-gen-twirpjs@latest

# For C# generation
go install github.com/seanpfeifer/twirp-gen/cmd/protoc-gen-twirpcs@latest

Ensure your ~/go/bin (Linux) or %USERPROFILE%/go/bin (Windows) are on your PATH.

Usage

# Typical Twirp usage to generate methods from the "examples" dir into "./examples_gen/generated.js"
protoc -I ./examples --twirpjs_out=./examples_gen/ ./examples/*.proto

# If you use twirp.WithServerPathPrefix(), eg `twirp.WithServerPathPrefix("/rpc")`, you can specify the
# prefix with the "pathPrefix" flag
protoc -I ./examples --twirpjs_out=pathPrefix=/rpc:./examples_gen/ ./examples/*.proto

# C# is the same as above two examples, but uses `--twirpcs_out`
protoc -I ./examples --twirpcs_out=./examples_gen/ ./examples/*.proto
protoc -I ./examples --twirpcs_out=pathPrefix=/rpc:./examples_gen/ ./examples/*.proto

JavaScript

This is an extremely simple generator for JavaScript, which communicates with JSON only. It makes a few assumptions to keep things simple:

• Your Twirp server has the option twirp.WithServerJSONCamelCaseNames(true) set
  • This client uses proto3 JSON serialization instead of the snake-case default in Twirp
• You are OK with the fetch() browser API
  • That is, you don't need to worry about older browsers that may not support it

C#

Another extremely simple generator, but for C#. This client makes requests using binary serialized Protobuf.

On error, the generated functions will throw a GeneratedAPI.Exception.

Unity Example

Note that this example does not deal with errors. It is just a simple example of how to call the generated functions.

using System.Net.Http;
using UnityEngine;
using Google.Protobuf; // For ByteString in this example

public class APICaller : MonoBehaviour {
  public const string SERVER_ADDRESS = "http://localhost:8080/";

  static readonly HttpClient client = new HttpClient();
  static APICaller() {
    client.BaseAddress = new System.Uri(SERVER_ADDRESS);
    client.DefaultRequestHeaders.Accept.Add(GeneratedAPI.CONTENT_TYPE_PROTOBUF);
  }

  // Start is called before the first frame update
  async void Start() {
    var checkoutResult = await GeneratedAPI.CreateCheckoutSession(client, new Shop.CheckoutRequest { ItemId = "item_cool_stuff" });
    Debug.Log(checkoutResult);

    var logoutResult = await GeneratedAPI.Logout(client, new Account.LogoutRequest { AccountId = 42, Token = ByteString.CopyFrom(new byte[]{1,2,3,4,5}) });
    Debug.Log(logoutResult);
  }
}