This repository is responsible for all of the deno-powered TypeScript <--> Rust interop. Currently this includes composition and query planning.
This repository has one long-running branch, main. The federation repository itself maintains two separate branches, version-0.x for Federation 1 and main for Federation 2.
You'll notice that there are three cargo workspaces in this repository. The first is the root which contains xtask and apollo-federation-types. The others are federation-1 and federation-2. Each of these workspace directories contains some binaries and some libraries. Building specific packages is orchestrated by xtask in CI.
IMPORTANT: If you are working locally, changes made to federation-1 and federation-2 WILL NOT be picked up by rust-analyzer or your cargo build/cargo test commands. There are a few tools to help you out here.
- You can run
code federation-rs.code-workspaceto open a VS Code Workspace that will run Rust-Analyzer properly. - You can run
cargo xtask testfrom the root workspace directory to run tests across all workspaces - You can open a new VS Code window for
federation-1and/orfederation-2andrust-analyzerwill work as expected. There might be some way to get something to work withrust-analyzer.linkedProjectsbut it wouldn't be straightforward and opening a new VS Code window is easy enough.
Each crate listed here has their own README with much more information than what's here.
The harmonizer crate is a library that provides the federation composition algorithm to the rest of Apollo's Rust ecosystem.
The supergraph crate is a binary that provides the federation composition algorithm as a CLI, primarily for integration with rover.
The apollo-federation-types crate provides types for all versions of harmonizer and supergraph, and is used by Rover to read the output from the supergraph binary.
The router-bridge crate is a library that provides the federation query-planning algorithm, primarily for integration with the router