Protect install target and add tests

tests/run_all.sh

@@ -24,6 +24,7 @@ run_test() {
 
 run_test "${ROOT_DIR}/tests/test_common.sh"
 run_test "${ROOT_DIR}/tests/test_cli.sh"
+run_test "${ROOT_DIR}/tests/test_install.sh"
 run_test "${ROOT_DIR}/tests/test_interactive.sh"
 run_test "${ROOT_DIR}/tests/test_storage.sh"
 run_test "${ROOT_DIR}/tests/test_env_check.sh"

tests/test_install.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)
+# shellcheck source=tests/lib/assert.sh
+source "${ROOT_DIR}/tests/lib/assert.sh"
+
+maybe_enter_namespace() {
+  if (( EUID == 0 )); then
+    return 0
+  fi
+
+  if [[ ${IPF_IN_NAMESPACE:-0} == 1 ]]; then
+    return 0
+  fi
+
+  if command -v unshare >/dev/null 2>&1 && unshare -Ur true >/dev/null 2>&1; then
+    exec unshare -Ur env IPF_IN_NAMESPACE=1 bash "$0"
+  fi
+
+  printf 'SKIP: 安装测试需要 root 或可用的 unshare。\n'
+  exit 0
+}
+
+status_of() {
+  set +e
+  "$@" >/dev/null 2>&1
+  local rc=$?
+  set -e
+  printf '%s\n' "${rc}"
+}
+
+maybe_enter_namespace
+
+TMP_DIR=$(mktemp -d)
+trap 'rm -rf "${TMP_DIR}"' EXIT
+
+TARGET_BIN="${TMP_DIR}/bin/iptables-forward"
+OTHER_TARGET="${TMP_DIR}/bin/not-ours"
+SOURCE_SCRIPT="${ROOT_DIR}/iptables-forward.sh"
+
+install_output=$(INSTALL_TARGET="${TARGET_BIN}" "${ROOT_DIR}/install.sh")
+assert_contains "${install_output}" '已创建链接:' 'install should create symlink on first run'
+[[ -L ${TARGET_BIN} ]] || fail 'install should create a symlink'
+assert_eq "${SOURCE_SCRIPT}" "$(readlink -- "${TARGET_BIN}")" 'install should link to project entry script'
+
+install_output=$(INSTALL_TARGET="${TARGET_BIN}" "${ROOT_DIR}/install.sh")
+assert_contains "${install_output}" '链接已存在:' 'install should be idempotent for existing project link'
+
+printf 'keep-me\n' >"${OTHER_TARGET}"
+assert_status '1' "$(status_of env INSTALL_TARGET="${OTHER_TARGET}" "${ROOT_DIR}/install.sh")" 'install should refuse to overwrite non-project target'
+assert_eq 'keep-me' "$(cat "${OTHER_TARGET}")" 'install refusal should keep existing target untouched'
+
+uninstall_output=$(INSTALL_TARGET="${TARGET_BIN}" "${ROOT_DIR}/install.sh" --uninstall)
+assert_contains "${uninstall_output}" '已删除链接:' 'uninstall should remove project symlink'
+[[ ! -e ${TARGET_BIN} && ! -L ${TARGET_BIN} ]] || fail 'uninstall should remove installed symlink'
+
+assert_status '1' "$(status_of env INSTALL_TARGET="${OTHER_TARGET}" "${ROOT_DIR}/install.sh" --uninstall)" 'uninstall should refuse to delete non-project target'
+assert_eq 'keep-me' "$(cat "${OTHER_TARGET}")" 'uninstall refusal should keep existing target untouched'
+
+pass 'test_install.sh'