Swift Package for Mozilla's Rust Components

This repository is a Swift Package for distributing releases of Mozilla's various Rust-based application components. It provides the Swift source code packaged in a format understood by the Swift package manager, and depends on a pre-compiled binary release of the underlying Rust code published from mozilla/application-services.

This repository is mostly updated by automation, all the logic is copied from mozilla/application-services

Overview

• The application-services repo publishes two binary artifacts MozillaRustComponents.xcframework.zip and FocusRustComponents.xcframework.zip containing the Rust code and FFI definitions for all components, compiled together into a single library.
• The Package.swift file refrences the xcframeworks as Swift binary targets.
• The Package.swift file defines a library per target (one for all the components used by firefox-ios and one for focus-ios)
  • Each library references its Swift source code directly as files in the repo. All components used by a target are copied into the same directory. For example, all the firefox-ios files are in the swift-source/all directory.
  • Each library depends on wrapper which wraps the binary to provide the pre-compiled Rust code. For example, FocusRustComponentWrapper wraps the Focus xcframework.

For more information, please consult:

• application-services ADR-0003, which describes the overall plan for distributing Rust-based components as Swift packages.
• The Swift Package Manager docs and GitHub repo, which explain the details of how Swift Packages work (and hence why this repo is set up the way it is).
• The ios-rust crate which is currently responsible for publishing the pre-built MozillaRustComponents.xcframework.zip and FocusRustComponents.xcframework.zip bundles on which this repository depends.

Releases

Nightly

Nightly releases are automated and run every night as a cron job that pushes directly to the main branch. Nightly releases are tagged with three components (i.e X.0.Y) where the first component is the current Firefox release (i.e 117, etc) and the last component is a timestamp.

Note that we need three components because that's a Swift Package manager requirement.

Cutting a Release

To cut a release of rust-components-swift, you will need to do the following:

• Run ./automation/update-from-application-services.py <X.Y>, where X.Y is the version of application services.
• Open a pull request with the resulting changes
• Once landed on the main branch, cut a release using the GitHub UI and tag it
  • IMPORTANT: The release tag must be in the form X.0.Y, where X.Y is the version of application services

Testing and Local development

To enable local development of rust-component-swift read the instructions documented in application services

Adding a new component

Check out the instructions in the docs in application-services for adding a new component and publishing it for iOS. The docs are also published for convenience in https://mozilla.github.io/application-services/book/index.html.

Filing issues with rust-components-swift

Please open a ticket in https://github.com/mozilla/application-services/issues for any rust-component-swift related issues.