#!/bin/bash
# 变异测试跑一次：$1=文件 $2=old $3=new $4=判据文件 $5=说明
set -u
f="$1"; old="$2"; new="$3"; t="$4"; why="$5"
BAK="${TMPDIR:-/tmp}/mut-bak-$$-$RANDOM.orig"   # ★ 不用固定名：并行跑会互相覆盖
cp -a "$f" "$BAK"
before=$(sha256sum < "$f")
python3 - "$f" "$old" "$new" <<'PY'
import sys
p,old,new=sys.argv[1],sys.argv[2],sys.argv[3]
s=open(p,encoding='utf-8').read()
n=s.count(old)
if n!=1:
    print(f"  [SKIP] 锚点出现 {n} 次（要恰好 1 次）：{old[:60]!r}"); sys.exit(3)
open(p,'w',encoding='utf-8').write(s.replace(old,new,1))
PY
rc=$?
if [ $rc -ne 0 ]; then cp -a "$BAK" "$f"; rm -f "$BAK"; echo "  [SKIP] $why"; exit 0; fi
node --test "$t" >/tmp/mut/out.txt 2>&1
trc=$?
cp -a "$BAK" "$f"
rm -f "$BAK"
after=$(sha256sum < "$f")
if [ "$before" != "$after" ]; then echo "  [!! 还原失败] $f  必须立刻处理"; exit 2; fi
if [ $trc -eq 0 ]; then
  echo "  [红不了·缺陷] $why"
else
  echo "  [红✓] $why"
fi