23 Oct 2019
- <a href="/authors/zhouyan.html">周岩</a>
Preface
由于脚本语言解释执行的特性，很多低级错误在运行到问题代码时才会报错，而不是像 C++ 这种静态语言那样在编译期就能由编译器检查出来，这就导致有很多本来在开发期就可以避免的问题，拖到线上才被发现。这里给出一个方案，可以在提交代码前，通过 Git 的 hook/pre-commit 机制，去做一些脚本代码的静态检查。
我用 Lua 比较多，这里就以 Lua 为例来进行说明。Lua 的静态检查工具基本上只有一个 luacheck 可用, 安装很简单，可以使用 luarocks 安装（类似 python 的 pip, 是一个 Lua 的包管理器）：
luarocks install luacheck
安装好以后可以直接在终端使用:
luacheck your_lua_file.lua
luacheck 的配置
默认的 luacheck 配置比较严格，会报很多警告，比如我们自定义的一些全局变量和函数，这当然是我们不希望看到的，既然要检查了，就要做到整个项目里所有文件都是 0 warnings / 0 errors。
配置方法：
新建 ~/.luacheckrc 文件, 然后在里面加上下面的内容, 这里面是我们项目的一些符号，大家可以根据自己项目实际需求来添加或删除。
-- 这个文件是一个 Lua 文件
– 每行最大长度，默认 120
max_line_length = 9999
– 忽略的符号
ignore = {
"init",
"exit",
"accept",
"response",
"class",
}
– 全局变量
globals = {
"Log",
"table.empty",
"table.size",
"table.merge",
"table.indexof",
"table.keys",
"table.values",
"table.valuestring",
"table.copy",
"table.deepcopy",
"table.first",
"table.deepmerge",
"table.walk",
"table.clear",
"string.split",
"string.ltrim",
"string.rtrim",
"string.trim",
"string.repeated",
"string.nocase",
"string.nocasefind",
"enum",
"ASSERT",
"ANSI_COLOR",
"const",
"math.round",
}
完整的配置说明请查看：https://luacheck.readthedocs.io/en/stable/config.html
Git pre-commit 配置
进入项目根目录下，然后 cd .git/hooks, 进去后输入 ls -ahl 会看到以下文件：
-rwxr-xr-x 1 zy staff 478B Jun 26 2018 applypatch-msg.sample
-rwxr-xr-x 1 zy staff 896B Jun 26 2018 commit-msg.sample
-rwxr-xr-x 1 zy staff 189B Jun 26 2018 post-update.sample
-rwxr-xr-x 1 zy staff 424B Jun 26 2018 pre-applypatch.sample
-rwxr-xr-x 1 zy staff 1.8K Oct 23 19:47 pre-commit.sample
-rwxr-xr-x 1 zy staff 1.3K Jun 26 2018 pre-push.sample
-rwxr-xr-x 1 zy staff 4.8K Jun 26 2018 pre-rebase.sample
-rwxr-xr-x 1 zy staff 544B Jun 26 2018 pre-receive.sample
-rwxr-xr-x 1 zy staff 1.5K Jun 26 2018 prepare-commit-msg.sample
-rwxr-xr-x 1 zy staff 3.5K Jun 26 2018 update.sample
我们把 pre-commit.sample 文件的后缀名去掉 mv pre-commit.sample pre-commit, 然后打开它，里面已经有一些内容了，我在这个基础上加上了 luacheck 的检查，可以直接用我提供的版本覆盖里面的内容：
#!/bin/sh
#
# An example hook script to verify what is about to be committed.
# Called by "git commit" with no arguments. The hook should
# exit with non-zero status after issuing an appropriate message if
# it wants to stop the commit.
#
# To enable this hook, rename this file to "pre-commit".
if git rev-parse –verify HEAD >/dev/null 2>&1
then
against=HEAD
else
# Initial commit: diff against an empty tree object
against=4b825dc642cb6eb9a060e54bf8d69288fbee4904
fi
# If you want to allow non-ASCII filenames set this variable to true.
allownonascii=$(git config –bool hooks.allownonascii)
# Redirect output to stderr.
exec 1>&2
# Cross platform projects tend to avoid non-ASCII filenames; prevent
# them from being added to the repository. We exploit the fact that the
# printable range starts at the space character and ends with tilde.
if [ "allownonascii" != "true" ] &&
# Note that the use of brackets around a tr range is ok here, (it's
# even required, for portability to Solaris 10's /usr/bin/tr), since
# the square bracket bytes happen to fall in the designated range.
test (git diff –cached –name-only –diff-filter=A -z $against |
LC_ALL=C tr -d '[ -~]