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 '[ -~]