Merge pull request 'feat(ci): run L0/L1 offline checks, mutation suites and yamllint in bounded parallel pools' (#149) from feat/parallel-l0-checks into main

Reviewed-on: #149
Reviewed-by: Keith Jackson <[email protected]>

ci/lint.sh

@@ -25,8 +25,44 @@ if [ "${#files[@]}" -eq 0 ]; then
   exit 0
 fi
 
-yamllint -c "${CI_DIR}/yamllint.yaml" -f "${YAMLLINT_FORMAT:-standard}" "${files[@]}"
-ok "yaml/lint passed (${#files[@]} files)"
+# yamllint is single-threaded, so the file list is split into LINT_JOBS CONTIGUOUS slices of the
+# sorted list, one yamllint per slice, run concurrently. Each slice's output goes to its own file
+# and the files are printed in slice order afterwards: the log is the same text, in the same
+# file order, as one serial `yamllint "${files[@]}"`, and a finding is never interleaved with
+# another process's output (yamllint's standard format puts the FILE NAME on its own line above
+# that file's `line:col` findings, so interleaving would misattribute them). The stage's exit
+# code is the highest any slice returned (yamllint: 1 = error, 2 = warning under strict), so a
+# single failing slice fails the stage exactly as the serial call did. LINT_JOBS=1 is serial.
+lint_jobs="${LINT_JOBS:-$(n="$(nproc 2>/dev/null || echo 1)"; [ "$n" -gt 8 ] && n=8; echo "$n")}"
+case "$lint_jobs" in ''|*[!0-9]*|0) err "LINT_JOBS must be a positive integer, got '${lint_jobs}'"; exit 2 ;; esac
+[ "$lint_jobs" -gt "${#files[@]}" ] && lint_jobs="${#files[@]}"
+lint_tmp="$(mktemp -d)"
+trap 'rm -rf "$lint_tmp"' EXIT
+per=$(( (${#files[@]} + lint_jobs - 1) / lint_jobs ))
+pids=()
+for (( i = 0; i < lint_jobs; i++ )); do
+  slice=("${files[@]:$(( i * per )):${per}}")
+  [ "${#slice[@]}" -gt 0 ] || break
+  ( rc=0
+    yamllint -c "${CI_DIR}/yamllint.yaml" -f "${YAMLLINT_FORMAT:-standard}" "${slice[@]}" \
+      >"${lint_tmp}/${i}.out" 2>&1 || rc=$?
+    echo "$rc" >"${lint_tmp}/${i}.rc" ) &
+  pids+=("$!")
+done
+wait "${pids[@]}" || true
+lint_rc=0
+for (( i = 0; i < ${#pids[@]}; i++ )); do
+  cat "${lint_tmp}/${i}.out"
+  # A slice that left no rc file died before yamllint returned: that is a failure, not a pass.
+  slice_rc="$(cat "${lint_tmp}/${i}.rc" 2>/dev/null || true)"
+  case "$slice_rc" in ''|*[!0-9]*) slice_rc=1 ;; esac
+  [ "$slice_rc" -gt "$lint_rc" ] && lint_rc="$slice_rc"
+done
+if [ "$lint_rc" -ne 0 ]; then
+  err "yaml/lint failed (yamllint exit ${lint_rc}; ${#files[@]} files in ${#pids[@]} parallel slice(s))"
+  exit "$lint_rc"
+fi
+ok "yaml/lint passed (${#files[@]} files, ${#pids[@]} parallel slice(s))"
 
 # A workflow's `configurationFile:` must name a file that exists. Renovate's did not after #79
 # renamed renovate.json -> renovate.json5, and every scheduled run failed with ENOENT for 11 days