ci.yml

name: CI

# Runs on a SELF-HOSTED macOS runner, not a GitHub-hosted one.
#
# Why: GitHub bills macOS runners at a 10x minute multiplier on private repos, so a
# single 5-8 minute build+test burns 50-80 billed minutes. The free allowance
# (2,000 min/month = 200 macOS minutes) would cover roughly three runs. Untenable
# for a repo under active development.
#
# A self-hosted runner is safe HERE specifically because this repo is private. Do NOT
# copy this to a public repo — a fork's pull_request can execute arbitrary code on the
# runner. (That caveat applies to link-devices, which is public.)
#
# The suite itself takes 0.7 seconds. All the cost is compiling and booting a
# simulator, both of which a warm persistent machine keeps around — so incremental
# runs land in well under a minute.

on:
  pull_request:
    paths:
      - 'Sources/**'
      - 'Tests/**'
      - 'project.yml'
      - '.github/workflows/ci.yml'
  push:
    branches: [main]
    paths:
      - 'Sources/**'
      - 'Tests/**'
      - 'project.yml'
      - '.github/workflows/ci.yml'
  workflow_dispatch:

# Pushing twice in a minute shouldn't queue two builds on a single machine.
concurrency:
  group: ci-${{ github.ref }}
  cancel-in-progress: true

jobs:
  test:
    runs-on: [self-hosted, macOS]
    timeout-minutes: 20

    steps:
      - uses: actions/checkout@v4

      - name: Environment
        run: |
          # The runner service does not inherit a login shell's PATH, so Homebrew
          # binaries (xcodegen) are not on it by default.
          echo "/opt/homebrew/bin" >> "$GITHUB_PATH"

      - name: Versions
        run: |
          xcodebuild -version
          /opt/homebrew/bin/xcodegen --version

      # project.yml is the source of truth; the .xcodeproj is gitignored and must be
      # regenerated. This also regenerates Info.plist — see project.yml's comment.
      - name: Generate Xcode project
        run: xcodegen generate

      - name: Test
        run: |
          set -o pipefail
          xcodebuild \
            -project KitchenSyncApp.xcodeproj \
            -scheme KitchenSyncApp \
            -destination 'platform=iOS Simulator,name=iPhone 17 Pro' \
            -resultBundlePath TestResults.xcresult \
            test

      - name: Upload results on failure
        if: failure()
        uses: actions/upload-artifact@v4
        with:
          name: xcresult
          path: TestResults.xcresult
          retention-days: 7