两年前编写的文章 Git Style,是参考业界实践对 Git 提交记录格式和分支模型所做的总结。本文在 Git Style 基础上,再次描述提交记录的格式和分支模型,并介绍两个工具 commitizen 和 gitflow,分别处理维护提交记录格式和分支切换的工作

Commit Message

在 Git Style 中已经介绍了提交记录(Commit Message)的格式,但是没有说明为什么要遵循这样的约定。事实上,这个格式参考了 AngularJS’s commit message convention,而 AngularJS 制定这样的约定是出于几个目的

  • 自动生成 CHANGELOG.md
  • 识别不重要的提交
  • 为浏览提交历史时提供更好的信息

后面简称 AngularJS’s commit message convention 为 conventional message。

格式

Conventional message 格式是这样的

<type>(<scope>): <subject>
<BLANK LINE>
<body>
<BLANK LINE>
<footer>

subject 是对变更的简要描述。

body 是更为详细的描述。

type 则定义了此次变更的类型,只能使用下面几种类型

  • feat:增加新功能
  • fix:问题修复
  • docs:文档变更
  • style:代码风格变更(不影响功能)
  • refactor:既不是新功能也不是问题修复的代码变更
  • perf:改善性能
  • test:增加测试
  • chore:开发工具(构建,脚手架工具等)

footer 可以包含 Breaking Changes 和 Closes 信息。

应用

node-trail-agent 项目遵循 conventional message,这里以这个项目举例,演示其应用场景。

CHANGELOG

通过 git log 可以生成 CHANGELOG.md 中版本间新增功能,

$ git log v0.4.0..v1.1.2 --grep feat --pretty=format:%s

feat: add "type" tag to distinguish client and server span
feat: instrument via Module._load hook

也可以同时获取修复的问题,

$ git log v0.4.0..v1.1.2 --grep 'feat\|fix' --pretty=format:%s

fix: wrapper function not returned
feat: add "type" tag to distinguish client and server span
feat: instrument via Module._load hook

定位错误

使用 git bisect 可以定位引入问题的提交,通过 type 可以快速辨别不会引入 bug 的提交,

(master) $ git bisect start
(master) $ git bisect bad
(master) $ gco v0.1.0
(7f04616) $ git bisect good

Bisecting: 15 revisions left to test after this (roughly 4 steps)
[433f58f26a53b519ab7fc52927895e67eb068c64] docs: how to use agent

(433f58f) $ git bisect good

Bisecting: 7 revisions left to test after this (roughly 3 steps)
[02894fb497f41eecc7b21462d3b020687b3aaee2] docs(CHANGELOG): 1.1.0

(02894fb) $ git bisect good

Bisecting: 3 revisions left to test after this (roughly 2 steps)
[9d15ca2166075aa180cd38a3b4d3be22aa336575] chore(release): 1.1.1

(9d15ca2) $ git bisect good

Bisecting: 1 revision left to test after this (roughly 1 step)
[f024d7c0382c4ff8b0543cbd66c6fe05b199bfbc] fix: wrapper function not returned

(f024d7c) $ npm test
...

因为 docs 或 chore 不会引入 bug,所以可以直接执行 git bisect good

使用 git bisect skip 可以直接过滤掉这些提交,

$ git bisect skip $(git rev-list --grep 'style\|docs\|chore' v0.1.0..HEAD)

Commitizen

命令行工具 commitizen 帮助开发者生成符合 conventional message 的提交记录。

成功安装并初始化 commitizen 后,通过调用 git cz 来提交代码,

$ git cz

Line 1 will be cropped at 100 characters. All other lines will be wrapped after 100 characters.

? Select the type of change that you're committing: (Use arrow keys)
❯ feat:     A new feature
  fix:      A bug fix
  docs:     Documentation only changes
  style:    Changes that do not affect the meaning of the code
            (white-space, formatting, missing semi-colons, etc)
  refactor: A code change that neither fixes a bug or adds a feature
  perf:     A code change that improves performance

提交后会按照 convertional message 格式化提交记录,

commit f024d7c0382c4ff8b0543cbd66c6fe05b199bfbc
Author: zhongchiyu <zhongchiyu@gmail.com>
Date:   Mon May 30 14:49:17 2016 +0800

    fix: wrapper function not returned

除此之外,commitizen 还依据 conventional message,创建起一个生态

使用这些工具可以简化 npm 包的发布流程,

#! /bin/bash

# https://gist.github.com/stevemao/280ef22ee861323993a0
# npm install -g commitizen cz-conventional-changelog trash-cli conventional-recommended-bump conventional-changelog-cli conventional-commits-detector json
trash node_modules &>/dev/null;
git pull --rebase &&
npm install &&
npm test &&
cp package.json _package.json &&
preset=`conventional-commits-detector` &&
echo $preset &&
bump=`conventional-recommended-bump -p angular` &&
echo ${1:-$bump} &&
npm --no-git-tag-version version ${1:-$bump} &>/dev/null &&
conventional-changelog -i History.md -s -p ${2:-$preset} &&
git add History.md &&
version=`cat package.json | json version` &&
git commit -m"docs(CHANGELOG): $version" &&
mv -f _package.json package.json &&
npm version ${1:-$bump} -m "chore(release): %s" &&
git push --follow-tags &&
npm publish

运行上述脚本会更新 CHANGELOG.md、升级版本号并发布新版本到 npm,所有这些操作都基于提交记录自动处理。

Branching Model

Vincent Driessen 的分支模型(Branching Model)介绍 Git 分支和开发,部署,问题修复时的工作流程,

workflow

Author: Vincent Driessen Original blog post: http://nvie.com/posts/a-succesful-git-branching-model License: Creative Commons BY-SA

在整个开发流程中,始终存在 master 和 develop 分支,其中 master 分支代码和生产环境代码保持一致,develop 分支还包括新功能代码。

分支模型主要涉及三个过程:功能开发,代码发布和问题修复

功能开发

  1. 从 develop 创建一个新分支(feature/*)
  2. 功能开发
  3. 生产环境测试
  4. Review
  5. Merge 回 develop 分支

代码发布

需要发布新功能到生产环境时

  1. 从 develop 创建新分支(release/*)
  2. 发布 feature 分支代码到预上线环境
  3. 测试并修复问题
  4. Review
  5. 分别 merge 回 develop 和 master 分支
  6. 发布 master 代码到生产环境

问题修复

当生产环境代码出现问题需要立刻修复时

  1. 从 master 创建新分支(hotfix/*)
  2. 发布 hotfix 代码到预上线环境
  3. 修复问题并测试
  4. Review
  5. 分别 merge 会 develop 和 master 分支
  6. 发布 master 代码到生产环境

该分支模型值得借鉴的地方包括,

  • 规范的分支命名
  • 将分支和代码运行环境关联起来

分支和代码运行环境的关系是这样的,

  • master => 生产环境
  • release/*,hotfix/* => 预上线环境
  • feature/*,develop => 开发环境

gitflow

Vincent Driessen 的分支模型将开发流程和Git分支很好的结合起来,但在实际使用中涉及复杂的分支切换,gitflow 可以简化这些工作。

安装并在代码仓库初始化 gitflow 后,就可以使用它完成分支工作流程,

$ git flow init

No branches exist yet. Base branches must be created now.
Branch name for production releases: [master]
Branch name for "next release" development: [develop]

How to name your supporting branch prefixes?
Feature branches? [feature/]
Release branches? [release/]
Hotfix branches? [hotfix/]
Support branches? [support/]
Version tag prefix? []

功能开发

开始开发时

(develop) $ git flow feature start demo

Switched to a new branch 'feature/demo'

Summary of actions:
- A new branch 'feature/demo' was created, based on 'develop'
- You are now on branch 'feature/demo'

完成开发后

(feature/demo) $ git flow feature finish demo

Switched to branch 'develop'
Already up-to-date.
Deleted branch feature/demo (was 48fbada).

Summary of actions:
- The feature branch 'feature/demo' was merged into 'develop'
- Feature branch 'feature/demo' has been removed
- You are now on branch 'develop'

代码发布

发布代码前

(develop) $ git flow release start demo

Switched to a new branch 'release/demo'

Summary of actions:
- A new branch 'release/demo' was created, based on 'develop'
- You are now on branch 'release/demo'

测试完成准备上线时

(release/demo) $ git flow release finish demo

Switched to branch 'master'
Deleted branch release/demo (was 48fbada).

Summary of actions:
- Latest objects have been fetched from 'origin'
- Release branch has been merged into 'master'
- The release was tagged 'demo'
- Release branch has been back-merged into 'develop'
- Release branch 'release/demo' has been deleted

发布 master 代码到线上环境

问题修复

发现线上故障时,

(master) $ git flow hotfix start demo-hotfix

Switched to a new branch 'hotfix/demo-hotfix'

Summary of actions:
- A new branch 'hotfix/demo-hotfix' was created, based on 'master'
- You are now on branch 'hotfix/demo-hotfix'

修复问题后

(hotfix/demo-hotfix) $ git flow hotfix finish demo-hotfix

Deleted branch hotfix/demo-hotfix (was 48fbada).

Summary of actions:
- Latest objects have been fetched from 'origin'
- Hotfix branch has been merged into 'master'
- The hotfix was tagged 'demo-hotfix'
- Hotfix branch has been back-merged into 'develop'
- Hotfix branch 'hotfix/demo-hotfix' has been deleted

相关链接