Setup Swift (on Windows) on GitHub Actions Builders

Automates installation of the Swift toolchain for Windows hosts on GitHub Actions runners.

NOTE: Only Swift 5.4.2+ is supported

• Sample workflow using official Swift releases

on: [pull_request]

jobs:
  windows:
    runs-on: windows-latest
    steps:
      - uses: compnerd/gha-setup-swift@main
        with:
          branch: swift-5.5-release
          tag: 5.5-RELEASE

      - uses: actions/checkout@v2
      - run: swift build
      - run: swift test

• Sample workflow using a custom Swift toolchain from a Github repository

on: [pull_request]

jobs:
  windows:
    runs-on: windows-latest
    steps:
      - uses: compnerd/gha-setup-swift@main
        with:
          release-tag-name: "20230530.2"
          github-repo: mycompany/swift-toolchain-build
          release-asset-name: installer-amd64.exe

      - uses: actions/checkout@v2
      - run: swift build
      - run: swift test

• branch: (Note: this is not a git branch name) the Swift "version" to be installed. This may be either a pre-release branch (e.g. swift-5.5-branch), a release branch (e.g. swift-5.5-release) or the development branch (swift-development).
• tag: (Note: this is not a git tag name) the actual build tag to install, minus the “swift-” prefix. May indicate a release snapshot (e.g. 5.5-DEVELOPMENT-SNAPSHOT-2021-09-18-a), development snapshot (e.g. DEVELOPMENT-SNAPSHOT-2021-09-28-a), or a release (e.g. 5.5-RELEASE).

• github-repo: Github repo in "owner/repo" format

• release-tag-name: Release tag name, can be found in github.com/<owner>/<repo>/releases

• release-asset-name: Asset name for the Swift installer executable in the release

• github-token: Optional Github token for fetching a release from a private repository