what is version control?

"version control is a system that records changes to a file or set of files over time so that you can recall specific versions later

Pro Git, a.k.a The Git Book

benefits

• collaboration
• understand what happened and why
• safe experimentation
• backup

what is git?

"git is a free and open source distributed version control system designed to handle everything from small to very large projects with speed and efficiency

git-scm.com

why git?

• all the cool kids use it
• relatively easy to learn
• tiny footprint
• lightning fast
• cheap local branching
• convenient staging area
• supports multiple workflows

a brief git history

https://upload.wikimedia.org/wikipedia/commons/3/3c/Sv-Linus_Torvalds2.ogg

Linus Torvalds

git commands

a few git commands

• git init - initialize a new repository
• git clone - copy a remote repository
• git status - um, the status
• git add - add files to the staging area
• git commit - commit staged changes to the local repository
• git log - see a history of commits
• git remote - tell git where to find a remote repository
• git pull - pull new commits from a remote repository
• git push - copy local commits to a remote repository
• git merge - bring commit histories together
• git rebase - change the base commit of a branch

lots more

basic workflow

solo workflow

visualizing

time

snapshot / commit

time

present

past

future

commits

branching

branching allows you to diverge from the main line

when to branch

• branch when you want to work in isolation
  • feature
  • bug
  • experiment

feature/xyz

commits

master

commit

branching
strategies

workflow matters!

models

• git flow
• continuous integration
• ...

git flow

http://nvie.com/posts/a-successful-git-branching-model/

strengths

• well known
• enables free experimentation
• methodical and controlled
• good code isolation

git flow

continuous integration model

master

feature/better-ness

bug/bad-thing

what if this happens...

instead of this?

conflict?

continuous integration model

strengths

• still enables free experimentation
• simple
• encourages smaller & more frequent releases
• accommodates continuous integration

workflow with branching

branching workflow

branch and rebase demo

👷🏼

rebase!!

best practices

should I commit?

🤔

should I push?

🤔

should I branch?

🤔

should I push to master?

🤔

anatomy of a good commit message

benefits of a good commit message

• zero-effort release notes
• faster code research
• bragging rights

subject rules

• subject is required & explains "what"
• contained within a single line
  • 50 characters or less
  • hard limit at 72 characters
• sentence case; no period at the end
• use the imperative mood
  • fix, add, remove, refine, improve, refactor
• subject should complete this sentence
  • if applied, this commit will...

https://chris.beams.io/posts/git-commit/

subject examples

Add .editorconfig

Update eslint settings to Facebook's recommended

Update dependency packages

Fix invalid mock nav data

Qualify loader names for webpack

Move eslint config into `.eslintrc.js`

body rules

• optional but recommended in many cases
• separated from the subject by a blank line
• 72 characters per line
• elaborate on "what" if needed
• explain "why"
  • business reasons / developer logic, etc
• don't explain how
  • the code diff explains how

########## RULES ############
# Capitalize the subject line
# Limit the subject line to 50 characters
# Do not end the subject line with a period
# Use the imperative mood in the subject line
# Separate subject from body with a blank line
# Wrap the body at 72 characters
# Use the body to explain what and why vs. how
#
##### SUBJECT ######
# Subject, 50 characters, 72 hard max ------50->|
# If you find it difficult to fit the subject into 50 characters --
# your commit is probably too big :-(
# Example imperative verbs: Fix, Add, Remove, Refine, Improve, Refactor
# If applied, this commit will...

 

##### DESCRIPTION #####
# Body, 72 characters so git can indent and stay under 80 --------72->|
# Elaborate what (if needed)
# Explain why (business reasons / developer logic, etc)
# Don’t explain how — code does that:

 

#
# Lines beginning with # are stripped from the git log

# git config --global commit.template ~/path/to/gitmessage.txt