name: conformance

# Fuzz tests that drive the renderer against real terminal emulators.
#
# They live in their own module (internal/conformance) because the reference
# emulator is a cgo package with a newer Go requirement, and neither cost
# belongs in the library that ships to users. That also means the root module's
# CI never runs them, so they get their own workflow here.

# push is scoped to main so a push to a PR branch fires only the
# pull_request run, not both. Merges to main still run via push.
on:
  push:
    branches: [main]
  pull_request:
  schedule:
    # A nightly coverage-guided run, so new bugs are found without waiting for
    # someone to run -fuzz by hand.
    - cron: "0 6 * * *"
  workflow_dispatch: {}

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v7

      - uses: actions/setup-go@v7
        with:
          go-version-file: ./internal/conformance/go.mod
          cache: true

      # Builds or restores libghostty-vt and puts it on PKG_CONFIG_PATH.
      - uses: ./.github/actions/libghostty-vt

      - name: Test
        working-directory: ./internal/conformance
        run: go test -count=1 -timeout 10m ./...


  # Coverage-guided fuzzing. This is deliberately not run on every push; it is
  # slow and its job is to find new bugs, not to gate commits. The test job
  # above already replays every known failing input on each push.
  fuzz:
    if: github.event_name == 'schedule' || github.event_name == 'workflow_dispatch'
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        target:
          - FuzzRenderer
          - FuzzRendererIdempotent
          - FuzzRedrawResyncs
          - FuzzScreenShowsContent
    steps:
      - uses: actions/checkout@v7

      - uses: actions/setup-go@v7
        with:
          go-version-file: ./internal/conformance/go.mod
          cache: true

      - uses: ./.github/actions/libghostty-vt

      - name: Fuzz ${{ matrix.target }}
        working-directory: ./internal/conformance
        run: go test -run='XXX' -fuzz='${{ matrix.target }}$' -fuzztime=15m

      # A new crasher is written under testdata/ on failure. Upload it so it can
      # be committed as a regression test rather than lost with the runner.
      - name: Upload new crashers
        if: failure()
        uses: actions/upload-artifact@v7
        with:
          name: crashers-${{ matrix.target }}
          path: internal/conformance/testdata/fuzz/
          if-no-files-found: ignore