zig-test.yml

# SPDX-License-Identifier: MPL-2.0
# Copyright (c) 2026 Jonathan D.A. Jewell (hyperpolymath) <j.d.a.jewell@open.ac.uk>
#
# BoJ Server — Zig FFI test & build pipeline

name: Zig FFI Tests

# NOTE: this workflow used to be workflow-level path-filtered (on.*.paths).
# That made it a REQUIRED check that simply never ran on PRs touching none of
# its paths — GitHub then left the check "Expected" forever and the PR sat at
# mergeable_state=blocked. It now always runs; a lightweight `changes` job
# decides whether the heavy `test` job is needed. A job skipped via `if:`
# reports SUCCESS to required status checks, so the required context is always
# satisfied without running heavy work on unrelated PRs.
on:
  push:
    branches: [main]
  pull_request:
    branches: [main]
  workflow_dispatch:

permissions:
  contents: read

jobs:
  changes:
    name: Detect relevant changes
    runs-on: ubuntu-latest
    timeout-minutes: 5
    outputs:
      run: ${{ steps.detect.outputs.run }}
    steps:
      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          fetch-depth: 0
      - id: detect
        env:
          EVENT: ${{ github.event_name }}
          BASE: ${{ github.base_ref }}
          BEFORE: ${{ github.event.before }}
        run: |
          # Fail-safe: default to running; only set run=false when a successful
          # diff shows NOTHING in this gate's path set changed.
          set -uo pipefail
          run=true
          if [ "$EVENT" = pull_request ]; then
            git fetch --no-tags --depth=200 origin "$BASE" 2>/dev/null \
              && changed=$(git diff --name-only "origin/${BASE}...HEAD" 2>/dev/null) \
              && { printf '%s\n' "$changed" | grep -qE '^ffi/|^cartridges/.*/ffi/' && run=true || run=false; }
          elif [ "$EVENT" = push ] && [ -n "$BEFORE" ] && [ "$BEFORE" != 0000000000000000000000000000000000000000 ]; then
            changed=$(git diff --name-only "${BEFORE}...${GITHUB_SHA}" 2>/dev/null) \
              && { printf '%s\n' "$changed" | grep -qE '^ffi/|^cartridges/.*/ffi/' && run=true || run=false; }
          fi
          printf 'run=%s\n' "$run" >> "$GITHUB_OUTPUT"
          echo "relevant=$run; changed files:"; printf '%s\n' "${changed:-<none computed>}"

  test:
    name: Zig FFI Tests
    needs: changes
    if: needs.changes.outputs.run == 'true'
    runs-on: ubuntu-latest
    timeout-minutes: 30
    steps:
      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          # Needed so `git diff origin/<base>...HEAD` can identify the
          # cartridges actually changed in this PR. Full history is cheap
          # on this repo; cuts down on cross-cartridge false-positive
          # gating where a PR is blocked by pre-existing breakage in
          # unrelated cartridges (browser-mcp, orchestrator-lsp-mcp,
          # etc.). On push/main we keep the full per-cartridge sweep.
          fetch-depth: 0

      - name: Install Zig
        uses: mlugg/setup-zig@d1434d08867e3ee9daa34448df10607b98908d29 # v2
        with:
          version: 0.15.2

      - name: Determine cartridges to test
        id: scope
        env:
          EVENT: ${{ github.event_name }}
          BASE_REF: ${{ github.base_ref }}
        run: |
          set -euo pipefail
          all="$(ls -d cartridges/*/ffi/ 2>/dev/null | sed 's|cartridges/||;s|/ffi/||' | sort)"
          if [ "$EVENT" = "pull_request" ]; then
            git fetch --no-tags --depth=50 origin "$BASE_REF" || true
            # Only scope cartridges whose `ffi/` actually changed —
            # `cartridge.json` edits (e.g. adding a status field) and
            # `abi/` edits should not pull a cart into this FFI test
            # job, which exists to validate Zig builds. Using
            # `cartridges/*/ffi/**` as the pathspec ensures only
            # ffi-relevant diffs count (also matches the workflow's
            # own `on.paths` filter — they were inconsistent before).
            changed="$(git diff --name-only "origin/${BASE_REF}...HEAD" -- 'cartridges/*/ffi/**' \
                       | awk -F/ '{print $2}' | sort -u)"
            scope=""
            while IFS= read -r cart; do
              [ -z "$cart" ] && continue
              if printf '%s\n' "$changed" | grep -qx "$cart"; then
                scope="$scope$cart"$'\n'
              fi
            done <<< "$all"
          else
            scope="$all"
          fi
          {
            echo 'carts<<EOF'
            printf '%s' "$scope"
            echo
            echo 'EOF'
          } >> "$GITHUB_OUTPUT"
          echo "Cartridges in scope for this run:"
          printf '  • %s\n' $(printf '%s\n' "$scope" | grep -v '^$' || true)

      - name: Run catalogue tests
        run: cd ffi/zig && zig build test --summary all

      - name: Run readiness tests
        run: cd ffi/zig && zig build readiness --summary all

      - name: Run cartridge FFI tests
        env:
          CARTS: ${{ steps.scope.outputs.carts }}
        run: |
          if [ -z "$(printf '%s' "$CARTS" | tr -d '[:space:]')" ]; then
            echo "::notice::No cartridges changed in this PR — skipping per-cartridge FFI tests."
            exit 0
          fi
          failed=""
          while IFS= read -r cart; do
            [ -z "$cart" ] && continue
            echo "::group::Testing $cart..."
            if cd "cartridges/$cart/ffi" && zig build test --summary all 2>&1; then
              echo "  ✓ $cart passed"
            else
              echo "  ✗ $cart FAILED"
              failed="$failed $cart"
            fi
            cd "$GITHUB_WORKSPACE"
            echo "::endgroup::"
          done <<< "$CARTS"
          if [ -n "$failed" ]; then
            echo "::error::Failed cartridges:$failed"
            exit 1
          fi

      - name: Build cartridge shared libraries
        env:
          CARTS: ${{ steps.scope.outputs.carts }}
        run: |
          if [ -z "$(printf '%s' "$CARTS" | tr -d '[:space:]')" ]; then
            echo "::notice::No cartridges changed in this PR — skipping per-cartridge .so build."
            exit 0
          fi
          while IFS= read -r cart; do
            [ -z "$cart" ] && continue
            echo "Building $cart .so..."
            cd "cartridges/$cart/ffi" && zig build
            cd "$GITHUB_WORKSPACE"
          done <<< "$CARTS"

      - name: Build static library
        run: cd ffi/zig && zig build lib

      - name: Run benchmarks
        run: cd ffi/zig && zig build bench