git-collaboration.md

#Git Collaboration

##Learning Objectives By the end of the lesson you should be able to...

• Collaborate on a git project
• Use feature branches appropriately
• Fix merge conflicts
• Use Github's features effectively

##Git tools for Collaboration

####git log

• Displays all the past commits
• Useful for viewing previous code changes and a list of individual contributions

####git diff

• Illustrates the changed lines of code between the current state and the last commit

##Feature Branching

Think about Elon Musk designing a car at Tesla

• There exists a 2014 master Tesla
• Elon wants to build a 2015 concept Tesla
• In order to preserve the master, he decides that it's better to copy the master than directly modify it
• Once copied Elon can feel free to iterate without any destructive consequences as he will now always be able to revert back to the existing 2014 master
• Once Elon is satisfied he can merge the concept features into a new 2015 master Tesla

in other words...

• A branch represents an independent line of development
• New features should be developed in a branch of the repository
• Once the feature is complete & working it can be merged into the main repository
• Commands
  • git branch <branch_name> — creates a new branch
  • git checkout <branch_name> — jumps into a specified branch
  • git merge <branch_name> master — merges a branch into master

##Merge Conflicts

• Occurs when there are disagreeing changes between your code and a previous commit
• This needs to be resolved before you can commit your code

Example conflict:

the number of planets are
<<<<<<< HEAD
nine
=======
eight
>>>>>>> branch-a

##Using Github Effectively

####Blaming

• Points out who change which lines in a file, showing the commit message

Example

####Diffing (again)

• Displays the changed lines of code in a set of files or file

Example

####History

• Shows readable history of all git commits and merges

Example

####Branches

• Enables one to view all the branches in a repository
• Again, branching is ideal for collaborating between individuals on team

Example

####Forking

• Creates a remote clone that you now own which you can make changes to
• This is particularly useful for open source projects
• Forking is great for collaborating between separate teams

####Pull Requests

• Used to request that a forked repository is merged or "pulled" into its associated upstream repository
• This allows the upstream repository owner the discretion of which forks can be merged
• Enables one to safely and freely submit code to any public repository

Example

####Issues

• Anyone can submit an issue for a public repo that the owner will be made aware of
• Issues are open by anyone if they have identified a problem in the code
• Issues are closed by the project owner once the problem is solved

Example

####Comments

• At the bottom of a specific commit, issue, or pull request you may leave a comment and @mention a user

####Wiki

• Typically used for more advanced documentation for your library; aka an expanded readme
• Also keep in mind, you can use it for whatever suits your needs best

Divise's Wiki

##Additional Resources

• Become a git guru
• How Git Works Video Overview
• Git deep-dive