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GIT – FÅ STYR PÅ
UDVIKLINGEN!
NETCOMPANY
2020-05-06
1.5
Rasmus Bækgaard
rab@netcompany.com
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• What is Git
• Practical theory
• Commands frequently used, and commit messages
• Branches
• Merging and merge conflicts (live demo)
• Rebasing
• Pull Requests (live demo)
• Strategies - How most projects are (/should be) using Git
• Goodies
• Questions
Agenda and focus
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“
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• USB-sticks
• .zip and .tar.gz
• Dropbox
• SVN/TFVS
History
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Misconception: Git is not a hosting service, and not a build agent
• Git is a tool to track your code.
• A hosting service is a place you keep your code (and more).
• Azure DevOps / TFS
• Bitbucket
• GitHub
• GitLab
• Most of these slides are only about the tool Git.
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Who uses what?
Source: Stack Overflow’s Developer Survey Results 2018
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The big change with a Git repository
• You can work offline.
• The mandatory synchronization is gone.
• You can make as many “commits” as you like without interrupting your colleagues’ work.
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Basic commands and functionality
• Git introduces new commands to use:
• Add
• Commit
• Fetch and Pull
• Push
• Branch
• Checkout (switch branch)
• Merge / Rebase
• Stash
• I have a cheat sheet you can get
after the talk, don’t worry.
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Branches and merges – the overview
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Branches and merges – the overview
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Branches and merges – Commit message
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Commit messages
• Why write the message?
• Speed up the reviewing process.
• The reviewer might not understand why
you made a change.
• How to write the message?
• Ask yourself “Why did you make the commit?”
• Imagine finishing the line “This commit will…“
• ‘Add’ / ‘Fix’ / ‘Remove’ / …
• The smaller the impact, the better.
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PAUSE
Du er velkommen til at stille spørgsmål i chatten
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Branches
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Branches
• Encapsulate what you are working on.
• Should have only one purpose.
• Make them short-lived.
• Work on multiple features if you need to.
• Don’t worry about other developers’ code.
• Naming:
• Feature/<Case ID>_<Title>
• Hotfix/<Title>
• Release/<Release ID>
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Merging
• Get one branch’s content into another
• Three variants of merging:
• Fast-forward
• No fast-forward
• Squash merge
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Branches and merge conflicts
• Live demo
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PAUSE
Du er velkommen til at stille spørgsmål i chatten
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Rebase
• Alternative to merging into your feature.
• Takes a copy of the commits and
moves them up.
• Takes a bit getting used to.
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Rebase – Best idea ever
• Make non-linear history linear
• Gives a nicer history.
• Can also modify the commits:
• Fewer commits
• Another message
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2020
Rebase – Best idea ever
1. Red branch is based on
an old master
2. Red branch is rebased
on the latest master
3. Red branch is merged
into master
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2121
Rebase – Best idea ever
GOLDER RULE OF REBASING:
NEVER EVER rebase a branch that has been
pushed.
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Rebase – Best idea ever
GOLDER RULE OF REBASING:
NEVER EVER rebase a branch that has been
pushed.
• Rebasing makes new commits, with new
content -> thereby new parents.
• Duplicate of the parents in both branches.
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Pull Requests
• Merging a Feature into Development/Releases/Master
• This is your code review.
• This is your ”can it still build”-check.
• This is your ”do all the unit tests flag green?”-check.
• Live demo
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PAUSE
Du er velkommen til at stille spørgsmål i chatten
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Workflow – What strategy to use?
• Release & Trunk (Master & Development)
• Latest release, and what is under development.
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Workflow – What strategy to use?
• Release & Trunk (Master & Development)
• Latest release, and what is under development.
• Multi-Release & Trunk (Master, Release 1.6, Release 1.7, Release 1.8, Development)
• Multiple branches with releases, and a branch for development.
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Workflow – What strategy to use?
• Release & Trunk (Master & Development)
• Latest release, and what is under development.
• Multi-Release & Trunk (Master, Release 1.6, Release 1.7, Release 1.8, Development)
• Multiple branches with releases, and a branch for development.
• Git Flow (Master, Release 1.6, Release 1.7, Release 1.8, Development, Feature/X, Feature/Y…)
• A branch for each release.
• A branch for each issue / case / feature.
• Merge with Pull Request
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Workflow – What strategy to use?
• Release & Trunk (Master & Development)
• Latest release, and what is under development.
• Multi-Release & Trunk (Master, Release 1.6, Release 1.7, Release 1.8, Development)
• Multiple branches with releases, and a branch for development.
• Git Flow (Master, Release 1.6, Release 1.7, Release 1.8, Development, Feature/X, Feature/Y…)
• A branch for each release.
• A branch for each issue / case / feature.
• Merge with Pull Request
• Git Flow with Blessed Repository
• Each team is developing their own version, and these will later be merged.
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Workflow – What strategy to use?
• Release & Trunk (Master & Development)
• Latest release, and what is under development.
• Multi-Release & Trunk (Master, Release 1.6, Release 1.7, Release 1.8, Development)
• Multiple branches with releases, and a branch for development.
• Git Flow (Master, Release 1.6, Release 1.7, Release 1.8, Development, Feature/X, Feature/Y…)
• A branch for each release.
• A branch for each issue / case / feature.
• Merge with Pull Request
• Git Flow with Blessed Repository
• Each team is developing their own version, and these will later be merged.
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Branches – in Git Flow
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Workflow – Git Flow
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Git good – good practices
• When starting a new issue/ticket/bug/feature, create a new branch
• You can switch to another if need be, and back again.
• Commit often
• When added a new test / refactored code in file / before doing something “risky”.
• And make a meaningful commit message every time.
• Push before you go home.
• Avoid lost work, and your branch is you own anyway.
• Merge only from a feature branch to the development branch using Pull Requests
• You review your own code and add additional information if something should happen in the release
notes.
• Someone else will read the code and add comments to it before accepting the changes.
• Delete the feature-branch when it has been merged into Master
• Both locally and on the remote.
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Tools
GUI Clients
• Git Extensions
• SourceTree
Code Editors
• Visual Studio
• IntelliJ
External Merge Tools
• P4Merge
• …
Command Line
• PowerShell with Git-Posh
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Goodies
Setup Git, and a cheat sheet:
https://github.com/bakgaard/GitSetup
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QUESTIONS?
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