Contributing

We'd love your help making Connect better!

If you'd like to add new public APIs, please open an issue describing your proposal — discussing API changes ahead of time makes pull request review much smoother. In your issue, pull request, and any other communications, please remember to treat your fellow contributors with respect!

Note that for a contribution to be accepted, you must sign off on all commits in order to affirm that they comply with the Developer Certificate of Origin. Make sure to configure git with the same name and E-Mail as your GitHub account, and run git commit with the -s flag to sign. If necessary, a bot will remind you to sign your commits when you open your pull request, and provide helpful tips.

Setup

Fork, then clone the repository:

git clone git@github.com:your_github_username/connect-swift.git
cd connect-swift
git remote add upstream https://github.com/connectrpc/connect-swift.git
git fetch upstream

You'll also need to install Xcode and Buf's CLI:

brew install bufbuild/buf/buf

This project uses Swift Package Manager for development and distribution. To get started contributing locally:

• Open Xcode.
• Click Open... and select the root connect-swift repo directory.
• Xcode will automatically read the Package.swift file and open the project.

Developing the Library

The Connect library's source code is available in the Libraries/Connect directory.

The easiest way to contribute to the library is to open the Xcode project and run the tests after making changes before finally submitting them.

Developing the Generator

The source code for the plugin that generates Connect-compatible services and RPCs is in the Plugins/ConnectSwiftPlugin directory, and the plugin responsible for generating mock implementations is in Plugins/ConnectMocksPlugin.

The plugins utilize the SwiftProtobufPluginLibrary module from SwiftProtobuf which provides types for interacting with the input .proto files and writing to stdout/stderr as expected by protoc.

To build the generator plugins, use Xcode or the following command:

make buildplugins

Generating Code

To build the local plugins and run them against the directories specified in the repository's buf.work.yaml files using Buf:

make buildplugins # Compile the plugins
make generate # Run buf generate

Outputted code will be available in the out directories specified by buf.gen.yaml files in the repository.

Running Tests

Conformance Tests

The various Connect implementations across languages leverage a shared conformance test repository which contains a test runner that accepts an executable provided by each library which exercises its runtime behavior. The test runner is responsible for performing a matrix of hundreds of runtime tests against a local server in order to validate behaviors with various permutations of protocols, codecs, etc. Connect-Swift's executable which is compatible with the conformance runner can be found under Tests/ConformanceClient. To install the runner and run the conformance test suite:

make installconformancerunner
make testconformance

Unit Tests

Unit tests live in the UnitTests directory and can be run using the following command which starts up a local server and runs the tests:

make testunit

Linting

Connect-Swift uses SwiftLint for linting .swift files. To install the linter locally, see the instructions. Ensure that the version you install matches the version being used on the run-swiftlint CI job.

You can run the linter by executing the following in the root of the repo:

swiftlint lint

Submitting Changes

Start by creating a new branch for your changes:

git checkout main
git fetch upstream
git rebase upstream/main
git checkout -b cool_new_feature

Ensure that the tests pass. If you are changing the generator plugins, also ensure that any generated diff is checked in.

git commit -a
git push origin cool_new_feature

Then use the GitHub UI to open a pull request.

At this point, you're waiting on us to review your changes. We try to respond to issues and pull requests within a few business days, and we may suggest some improvements or alternatives. Once your changes are approved, one of the project maintainers will merge them.

We're much more likely to approve your changes if you:

• Add tests for new functionality.
• Write a good commit message.
• Maintain backward compatibility.

Updating Dependencies

To update dependencies such as SwiftProtobuf in this repository:

1. Update the main library's Package.swift file with the new version.
2. Open the project to ensure the Package.resolved file gets updated by Xcode.
3. Update the versions in both the Connect-Swift.podspec and Connect-Swift-Mocks.podspec files.
4. Open the Swift package example app to ensure its Package.resolved file gets updated.
5. Run pod update in the CocoaPods example app's directory.
6. Update remote plugin entries (such as buf.build/apple/swift) in all buf.gen.yaml files to be in sync with their respective runtime libraries.
7. Run make buildplugins && make generate to apply any generated diffs from the newly updated plugins.

Releasing

Releases should be tagged in x.y.z SemVer format.

1. Update both Connect-Swift.podspec and Connect-Swift-Mocks.podspec to reflect the upcoming version on main. In the same PR, update the example CocoaPods app by running cd Examples/ElizaCocoaPodsApp && pod install.
2. Create a new GitHub release/tag after merging these changes.
3. CI will automatically push the updated specs to CocoaPods in its release job.