Introduction to code check-in and its importance

As we move forward in writing code and scripts, we also need to ensure they are stored somewhere for quick access. In today's world, where we can work from virtually anywhere, it's nearly impossible to work on only one machine everywhere you go.

Additionally, when we write a set of scripts and multiple team members are involved, we need to find a way to share our code and current updates on the code in real-time. This helps each of the contributors to be updated on each other's code to avoid redundant code. There are multiple techniques to ensure we can store our code/collaborate on code-writing and distribute the code to other engineers, but most code-sharing is done through Git.

Apart from collaboration and code-sharing, a very important use case for a code check-in is to keep your code stored in an environment where an abrupt crash or any local hardware issue (even a stolen computer) would not make your hours or weeks of efforts come to a standstill.

Let's start by creating a sample account at GitHub code hosting platform where user(s) can check-in the code, perform an initialization in a local machine, and perform a code check-in.

Git installation and initialization

Git is a version control system which tracks the changes when working with computer codes while GitHub is a web-based Git version control repository hosting service. Git is installed on a local computer whereas GitHub is hosted on web platform. In our test scenario, we will utilize the free Git service by signing up and creating our repository online at https://github.com/.

The following steps guide us through creating a repository in Git:

1. Click on New repository:

2. Give a name to the repository (in this case, mytest), and click on Create repository:

3. Note the instructions to clone (that is, make a copy of this repository) on your local machine:

4. Download and install the Git client from https://git-scm.com/downloads, choosing the release for the OS of the machine. In our test, we have a Windows 10 machine, hence we are using the Git client for Windows.
5. Follow the instructions to clone the Git repository in your specific folder. From Command Prompt, run the following command:

 C:\test>git clone https://github.com/pnaedition2/mytest.git
 Cloning into 'mytest'...
 warning: You appear to have cloned an empty repository.
 C:\test>cd mytest
 C:\test\mytest>git pull
 Your configuration specifies to merge with the ref 'refs/heads/master'
 from the remote, but no such ref was fetched.

6. To confirm (validate) if configuration is working, get a Git status:

C:\test\mytest>git status
On branch master
No commits yet
Untracked files:
(use "git add <file>..." to include in what will be committed)
git
nothing added to commit but untracked files present (use "git add" to track)

Code check-in

As we have the Git environment initialized in our local computer, we will proceed with a code check-in of a simple Python script:

1. Confirm that the file that needs to be checked in exists in the folder:

 Directory of C:\test\mytest
 12-Nov-18 03:16 PM <DIR> .
 12-Nov-18 03:16 PM <DIR> ..
 12-Nov-18 03:12 PM 0 git
 12-Nov-18 03:16 PM 34 myfirstcodecheckin.py
 2 File(s) 34 bytes
 2 Dir(s) 345,064,542,208 bytes free

2. If the file has not been added to git, it would show up in the git status command under untracked files:

C:\test\mytest>git status
On branch master
No commits yet
Untracked files:
(use "git add <file>..." to include in what will be committed)
git
myfirstcodecheckin.py
nothing added to commit but untracked files present (use "git add" to track)

3. Add this file for the code check-in and validate it again using git status (the added file will now show under the Changes to be committed section):

C:\test\mytest>git add myfirstcodecheckin.py
C:\test\mytest>git status
On branch master
No commits yet
Changes to be committed:
(use "git rm --cached <file>..." to unstage)
new file: myfirstcodecheckin.py
Untracked files:
(use "git add <file>..." to include in what will be committed)
git

4. Commit this particular change to the master (in other words, ensure the local copy is now saved on the server, ready to be shared with others):

C:\test\mytest>git commit -m "this is a test checkin"
[master (root-commit) abe263d] this is a test checkin
Committer: Abhishek Ratan <[e-mail]>

1 file changed, 1 insertion(+)
create mode 100644 myfirstcodecheckin.py

The -m in this section specified a comment for this particular code check-in. This generally depicts what code is being checked in and is treated like a remark section for this particular check-in.

5. We need to push our changes back to the server hosted on the web:

C:\test\mytest>git push
Counting objects: 3, done.
Writing objects: 100% (3/3), 273 bytes | 273.00 KiB/s, done.
Total 3 (delta 0), reused 0 (delta 0)
remote:
remote: Create a pull request for 'master' on GitHub by visiting:
remote: https://github.com/pnaedition2/mytest/pull/new/master
remote:
To https://github.com/pnaedition2/mytest.git
* [new branch] master -> master

This completes the check-in process for a specific file (or code script). To confirm that the process was successful, we can go to the GitHub URL of your repository to see the file:

As a final note, the next time someone clones the Git repository on a different machine, they just need to do a simple git pull for the same files to be visible and as a local copy on that particular machine. A similar approach can be followed for subsequent check-ins, as well as modifications to current files.

As best practice, always perform git pull before git push, to ensure you have the updated code in your local repository before your push out any code back to the main repository.