At the heart of an efficient SDLC lies the Source Code Management (SCM).

I use Git along with Bitbucket for collaboration between our development teams.  

A Distributed Version Control System (DVCS) has been a crucial component for successful collaboration among developers. While there have been many utilities developed for SCM (SVN, Fossil, Git) through the last few decades, Git became the most preferred by developers. The credibility of this specific tool has been proven by multiple open source projects, specifically due to the Linux kernel for which it was developed by Linux Torvalds. Not to mention that GitHub itself - The Source Code Management service - uses Git at its core and has made it easy for new developers and open-source projects to adopt it.

I am going to walk you through the most commonly used Git commands using a workflow.

This guide includes certain git commands along with their explanation of what it does along a workflow.

A git project begins with a directory initiation where the source code is stored.

$ cd path/to/project_directory

$ git init

After few files have been added to the project directory, these new files have to be added to git to be tracked for changes

$ git add server.js app.js

If many more files have been added to the directory and you want to add all of them for git to track for changes use the below command

$ git add .

Once the files are added, these files have to be committed to git so that you can track what changes were made when

$ git commit -m “Adding app.js for initial project configuration”

The above method is a way of writing short commit messages. 

You may write a commit message with a lot of description for the changes you have made with the below command.

This command would not work if you have already made the commit with short message from above

$ git commit

Once the commit message has been added it is time to push the repository to the SCM so other developers can pull and work on the project too.

$ git push

To push the changes to a Source Code Management service you will have to sign up to a service similar to Bitbucket, Github or Gitlab.

For advancing this guide I am using the bitbucket for SCM.

$ git remote -v

For adding a remote repository which has been created at bitbucket you would have a similar URL repo for your bitbucket repository.

$ git remote add origin https://bitbucket-username@bitbucket.org/bitbucket-workspace/your -project-repo.git

Now you are ready to push your changes

$ git push

The previous section of git is good enough to get you started with pushing code.

The real-world workflow often includes code moving through different branches.

As per the above diagram, the workflow is:

This is how the flow of the code would be using commands

Check the list of all branches

$ git branch -v

Creating new branch from the current branch

$ git checkout -b feature_auth

If a local branch already exists, the developer would simply have to switch/checkout the branch

$ git checkout feature_auth

Once the changes have been made to the local branch, add the files and commit these changes.

$ git add .

$ git commit -m “Feat: initial authentication commit”

Pushing the changes to centralised bitbucket repository

$ git push

If the previous command fails, since this is a new branch then this new branch information must be pushed to the central repository.

Here are all Three commands which do this but maybe outdated according to the git version.

$ git push --set-upstream origin feature_auth

$ git push --set-upstream-to origin feature_auth

$ git push -u origin feature_auth

Now the local branch named feature_auth is to be merged into the develop branch.

This is an example of how a one branch is merged into another branch but in real-world workflow a lot of branches will be merging into this develop branch

Once all the commits have been made to local branch, switch/checkout to develop branch

$ git checkout develop

Once switched/checkout to develop branch merge the local branch

$ git merge feature_auth

In the real-world you won’t be doing branch merges through a command. It will be done using PR (Pull Request) which is how SCMs manage merges for collaboration. 

Instead of doing a “git merge” of feature_auth to develop, you would be raising a Pull request for merging feature_auth to develop.

This PR is reviewed and then merged to the target branch from a centralized SCM service like Bitbucket or Github.

While you have been working on your project you can view the changes between your work and the previous commits

Listing all of your commits shows you the commit hash (hexadecimal), Author, Date and Commit message

$ git log

See the changes made between Two different commits 

$ git diff c390f88c9c419368270f582d6f2bae72df29d465 735d1bba6fd993eb8cc93fde33cd2a0455194dcf

The format of changes displayed by git diff includes

There is a possibility of different collaboration workflows depending on how organizations are set up. A git repository could be used by a single team or multiple teams in case of an open-source repository.

A developer working on the project would go through these processes

1. Clone an existing project’s git repository

$ git clone <REMOTE_URL>

2. Adding changes

$ git checkout -b feature_WM12

3. Merge new changes from development into your local branch

$ git merge origin/develop

4. Push

5. Create PR

A developer working on the project would go through these processes

1. Fork the repository

2. Adding changes

3. Push

4. Create PR to upstream

Git uses your email address as your identification for commits

Here is how to globally configure your email address and name for git

$ git config --global user.name “Sachin D”

$ git config --global user.email “sachin@givmail.com”

The difference between global and local configuration is that global is used for all git repos you work on.

While local can help you use a different identity (email) for each git repository.

$ git config --local user.name “Sachin D”

$ git config --local user.email “sachin@givmail.com”

Have you created too many branches? You may delete them

$ git branch -d feature_auth

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That's it for now :)

Comment if you have any question, happy to develop!