protoc-gen-twirp_ruby - A protoc plugin for Twirp-Ruby.

This gem is a protoc plugin that generates Twirp-Ruby services and clients.

Why use this?

Twirp-Ruby already does this via a go module. So why use this version?

• Easier install (just add the gem).
• You already know and love Ruby.
• We're committed to keeping it up to date.

The Go version works fine (we used it for years) but it was missing features that we wanted. Building in Ruby allows us to iterate quicker and makes it easier for others to contribute.

Installation

Install protoc

The Protocol Buffers protoc command is used to auto-generate code from .proto files.

• MacOS: brew install protobuf
• Ubuntu/Debian: sudo apt-get install -y protobuf
• Or download pre-compiled binaries: https://github.com/protocolbuffers/protobuf/releases

protoc is able to read .proto files and generate the message parsers in multiple languages, including Ruby (using the --ruby_out option). It does not generate Twirp services and clients; that is where our plugin comes in.

Install the protoc-gen-twirp_ruby plugin

Run gem install protoc-gen-twirp_ruby or add it to your Gemfile:

gem "protoc-gen-twirp_ruby", group: :development

If you previously used the Go version, see our Migration Instructions.

Usage

Pass --twirp_ruby_out to protoc to generate Twirp-Ruby code:

protoc --proto_path=. --ruby_out=. --twirp_ruby_out=. ./path/to/service.proto

Options

You can configure the code generation. Pass options by specifying --twirp_ruby_opt=<option> on the protoc command line.

• generate=<service|client|both>: Customize generated output to include generated services, clients, or both. Optional, defaults to both to preserve backwards compatibility.
  • generate=service - only generate ::Twirp::Services.
  • generate=client - only generate ::Twirp::Clients.
  • generate=both - default; generate both services and clients.

Example :

protoc --proto_path=. --ruby_out=. --twirp_ruby_out=. --twirp_ruby_opt=generate=client ./path/to/service.proto

Migrating from the Go module

If you previously installed the protoc-gen-twirp_ruby Go module via the Twirp-Ruby's Code Generation wiki page instructions, then you'll want to uninstall it before invoking the protoc command.

rm `go env GOPATH`/bin/protoc-gen-twirp_ruby

Differences from the Go module

This gem generates nearly identical Twirp-Ruby output as the Go version. Some notable differences that might affect migration include:

• Generated output code is in standardrb style.
• Generated service and client class names are improved for well-named protobuf services. See #6.
• Supports ruby_package in .proto files
• Supports protoc command line configuration options.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run bundle exec rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To experiment with development changes, route protoc to the local plugin when generating code via the --plugin=protoc-gen-twirp_ruby=./exe/protoc-gen-twirp_ruby option. For example:

protoc --plugin=protoc-gen-twirp_ruby=./exe/protoc-gen-twirp_ruby --ruby_out=. --twirp_ruby_out=. ./example/hello_world.proto

Alternatively, install the local gem before invoking protoc:

bundle exec rake install
protoc --ruby_out=. --twirp_ruby_out=. ./example/hello_world.proto

Releasing

Install the GitHub CLI: brew install gh or follow the instructions.

To release a new version:

• Submit a PR with the following changes (see e.g. #30):
  • Update the version number in version.rb
  • Update the CHANGELOG.md
    • Create a section for the new version and move the unreleased version there
  • Re-generate the example: bundle exec rake example
• Once merged and main is up-to-date, run bundle exec rake release.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/collectiveidea/protoc-gen-twirp_ruby.