protoc-types

The protoc.contrib.* proto packages: the options the protoc-contrib plugins read, in one place, with their Go and Rust bindings.

A schema annotated for one plugin is often generated for several. A message shared by a Go and a Rust service declares its defaults once, and both protoc-gen-go-defaults and protoc-gen-rust-defaults read them. So the options live here, not in any one plugin, and every plugin, every binding and every schema uses the same copy.

What is here

Package	Read by	Go	Rust
protoc.contrib.defaults	protoc-gen-go-defaults, protoc-gen-rust-defaults	github.com/protoc-contrib/protoc-types/contrib/defaults	protoc_types::contrib::defaults
protoc.contrib.json	protoc-gen-go-json	github.com/protoc-contrib/protoc-types/contrib/json	protoc_types::contrib::json

The protos live under proto/, the module root, so schemas import them as protoc/contrib/.... The Go and Rust paths mirror the package without its protoc. prefix, which the repository name already carries.

Using the options in a schema

The protos are published to the Buf Schema Registry as buf.build/protoc-contrib/protoc-types:

# buf.yaml
version: v2
deps:
  - buf.build/protoc-contrib/protoc-types

import "protoc/contrib/defaults/options.proto";

message ListBooksRequest {
  int32 page_size = 1 [(protoc.contrib.defaults.value).int32 = 50];
}

Using the bindings

Go:

go get github.com/protoc-contrib/protoc-types

Rust, from GitHub, pinned to a rev: there are no crates.io releases, so a branch would let the crate change under a build that did not ask it to.

[dependencies]
protoc-types = { git = "https://github.com/protoc-contrib/protoc-types", rev = "..." }

Generated code for both languages is committed, so neither needs buf or protoc to build.

A Rust crate whose build script compiles a schema importing these protos can take their include root from this crate, rather than vendoring a copy: list protoc-types under [dependencies], and Cargo hands the build script DEP_PROTOC_TYPES_PROTO, the path of proto/ at the pinned rev.

// build.rs
let protos = std::env::var("DEP_PROTOC_TYPES_PROTO")?;
// ... protoc -I{protos} ..., or buffa_build::Config::includes(&[&protos, ...])

Extension numbers

Every package extends the same google.protobuf.*Options messages, so its numbers must not collide with another's on the same extendee. contrib/extensions_test.go fails if they do.

Range	Package
55001–55004	protoc.contrib.defaults
55100	protoc.contrib.json

A new package takes the next free block of 100.

Adding or changing a proto

nix develop
buf lint
buf generate                                    # Go bindings, in contrib/
UPDATE_GENERATED=1 cargo test --test generated  # Rust bindings, in src/generated
go test ./... && cargo test

Commit the generated code with the proto. CI fails if either is stale.

License

Apache 2.0