linux-x86-render-smoke.yml

name: Linux x86 Render Smoke

# Proves the real WASM viewer renders on Linux (#247).
#
# On Linux the viewer runs under WebKitGTK, where WebGL2 is unavailable on an
# OffscreenCanvas, so the worker posts frames for the main thread to draw. That
# path had no CI coverage at all: the wheel smoke that renders a sketch is
# enabled only in macos-arm-build.yml. #247 therefore reached a release branch
# and could only be found by hand.
#
# This lane compiles a sketch and renders it in the shipped viewer under Xvfb
# with software GL, then requires the screenshot to contain lit pixels
# (ci/check_render.py). A viewer that loads and draws nothing fails here, which
# is exactly how #247 and #250 presented.
#
# It renders tests/fixtures/wasm_no_screenmap: a plain strip, which is also the
# #250 regression (its layout only exists after the first frame). A heavier
# sketch is deliberately not used — a 16x16 grid through llvmpipe on a 2-core
# runner starves the page's event loop and the harness times out.

on:
  push:
    branches: [main]
  pull_request:
    types: [opened, synchronize, reopened, labeled, unlabeled]
  workflow_dispatch:
    inputs:
      candidate_sha:
        description: Exact 40-character commit SHA to validate
        required: true
        type: string
# One live run per workflow per ref: a new push to a branch or PR cancels the
# superseded run instead of queuing behind it in the shared account-wide runner
# pool. Runs on main get a unique group, so they are never cancelled or coalesced.
concurrency:
  group: ${{ github.workflow }}-${{ github.ref == 'refs/heads/main' && github.run_id || github.ref }}
  cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}

jobs:
  render-smoke:
    if: github.event_name == 'workflow_dispatch' || (github.event_name == 'pull_request' && contains(github.event.pull_request.labels.*.name, 'ci-full'))
    runs-on: ubuntu-24.04
    timeout-minutes: 45
    defaults:
      run:
        shell: bash
    env:
      PYTHONIOENCODING: utf-8
    steps:
      - uses: actions/checkout@v4
        with:
          ref: ${{ github.event_name == 'workflow_dispatch' && inputs.candidate_sha || github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
      - name: Verify checkout SHA
        env:
          EXPECTED_SHA: ${{ github.event_name == 'workflow_dispatch' && inputs.candidate_sha || github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
        run: |
          [[ "$EXPECTED_SHA" =~ ^[0-9a-f]{40}$ ]]
          if [[ "$GITHUB_EVENT_NAME" == workflow_dispatch ]]; then
            test "$EXPECTED_SHA" = "$GITHUB_SHA"
          fi
          test "$(git rev-parse HEAD)" = "$EXPECTED_SHA"

      - uses: astral-sh/setup-uv@v5
        with:
          enable-cache: true
          python-version: "3.11.9"

      - name: Install Python
        run: uv python install "$UV_PYTHON"

      # Before setup-soldr, so its dependency cook can find GLib (#262).
      - name: Install system dependencies
        run: |
          sudo apt-get update -qq
          sudo apt-get install -y -qq libgtk-3-dev libwebkit2gtk-4.1-dev libayatana-appindicator3-dev librsvg2-dev
          # The viewer needs a display, and the runner has no GPU.
          sudo apt-get install -y -qq xvfb libgl1-mesa-dri

      - uses: zackees/setup-soldr@v0 # v0.9.82 or later (floating major)
        env:
          GITHUB_TOKEN: ${{ github.token }}
        with:
          # Same cache namespace as the other ubuntu-24.04 debug builds.
          cache-preset: foundation
          cache-key-suffix: ubuntu-24.04-native
          linker: platform-default
          toolchain-file: rust-toolchain.toml
          prebuild-deps-flags: ""

      - name: Build the fastled binary
        run: soldr cargo build --bin fastled

      - name: Start Xvfb
        run: |
          Xvfb :99 -screen 0 1280x1024x24 >"$RUNNER_TEMP/xvfb.log" 2>&1 &
          # Wait for the server's socket rather than a probe tool, so this needs
          # nothing beyond xvfb itself.
          for _ in $(seq 1 30); do
            if [ -S /tmp/.X11-unix/X99 ]; then break; fi
            sleep 1
          done
          test -S /tmp/.X11-unix/X99 || { cat "$RUNNER_TEMP/xvfb.log"; exit 1; }

      - name: Render a sketch in the shipped viewer
        env:
          DISPLAY: ":99"
          GDK_BACKEND: x11
          LIBGL_ALWAYS_SOFTWARE: "1"
          WEBKIT_DISABLE_COMPOSITING_MODE: "1"
        run: |
          mkdir -p "$RUNNER_TEMP/render"
          cp -R tests/fixtures/wasm_no_screenmap/. "$RUNNER_TEMP/render/"
          ./target/debug/fastled "$RUNNER_TEMP/render" \
            --test \
            --test-wait-secs=2 \
            --test-timeout-secs=600 \
            --test-ready-timeout-secs=180 \
            --test-exit-on-error \
            --test-screenshot="$RUNNER_TEMP/render.png" \
            --test-log="$RUNNER_TEMP/viewer.log"

      - name: Require a real render, not just a viewer that loaded
        run: uv run --no-project python ci/check_render.py "$RUNNER_TEMP/render.png"

      # The late-screenmap recovery is what makes this sketch renderable at all
      # (#250); assert it took the intended path rather than some other one.
      - name: Check the late screenmap recovery
        run: grep -F "[fastled] late screenmap recovered" "$RUNNER_TEMP/viewer.log"

      - name: Upload the render and the viewer log
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: linux-render-smoke
          path: |
            ${{ runner.temp }}/render.png
            ${{ runner.temp }}/viewer.log
            ${{ runner.temp }}/xvfb.log
          if-no-files-found: warn
          retention-days: 7