Learn the basics of version control to become a master

15 March 2020Gary Woodfine6 min read

Many people believe that in order to become a good software developer, engineer or coder that you will need to be able to write good code fast. The truth is, that in order to write good code, you first need to be able read, comprehend and understand code written by others.

It's also a common misconception that software developers are geeks or hackers working in isolation tapping furiously on their keyboards whilst solving deep and complex problems.

The reality is, developers probably spend only 10% of their time actually writing code. This fact, is also discussed in The Mythical Man-Month: Essays on Software Engineering, whereby the average developer will generally contribute on average 10 lines of code a day.

Professional Software Developers, know that there is a significant difference in rate between adding new lines of code to an existing large project, against starting a new project from scratch. The difference being that when adding new lines to large project, a majority of developer time, is typically spent figuring out relationships between constituent parts of the application code.

Therefore, 90% of developer time, is spent:

  • Reading
  • Interacting
  • Engaging
  • Collaborating
  • Integrating
  • Re-purposing
  • Re-engineering
  • Rewriting

This may be code developed by other software developers from all over the world.

In all likelihood, on any given project, the majority of the code contained in it, will be code from many different sources. You will invariably make use of Libraries, Frameworks, Components, Shared Code and at time Copy and Pasted code from other sources. Even the programming language you choose to develop your software is based on code developed by others.

Software development, is very much a team sport, the difference being that in all probability you will never meet or even know everybody on your team or contributing to your project. The only aspect of those people you're ever going to physically see, is their code.

Source Code Repository

The primary means developers interact with another and code, is through what is called a Source Code Repository and there are different types. Source Code Repositories can be either Public or Private and sometimes they can be a mixture of both.

repository

  1. a place or container in which things can be stored for safety
  2. a place where things are kept for exhibition; museum
  3. (Commerce) a place where commodities are kept before being sold; warehouse
  4. a place of burial; sepulchre
  5. a receptacle containing the relics of the dead
  6. a person to whom a secret is entrusted; confidant

Private Source Code Repositories

These are generally used by individuals, companies or organisations that only want to share their source code with individuals, companies or other organisations they trust. Often to protect Copyright, Patents or to store source code which is proprietary - meaning code that is for sale.

Public Source Code Repositories

A public source code repositories, are used by developers to share code with anybody, essentially the Public in this context. Typically, software project which make use of Public Source Code Repositories are termed as Open Source Projects, which loosely means the source code is free to see, read and share by anyone.

There are different licensing models available which sometimes could restrict you or even require payment for you to use the software, but generally most Open Source Projects can be free to use too.

Why use a version control system

Version control systems are a category of software tools that help software teams manage change to source code over time. Version control software keeps track of every modification to the code in a special kind of database. If mistakes are made, developers are able to revert changes to essentially turn back time and compare earlier versions of code to not disrupt the code base while minimizing disruption to all team members.

In order to develop quality software, software teams need to be able to track all changes and reverse them if necessary. Version control systems fill that role by tracking project history and helping to merge changes made by multiple people. They also assist in helping to speed up work and help teams to find bugs easier.

Working in distributed teams was made possible thanks to Version Control systems, because they enable developers to work on different parts of the project at the same time and later merge all their work into a single product.

How version control systems changed the software development world

Before version control systems were adopted by software teams, many teams relied on manually backing up previous versions of projects. Manually copying modified files in order to incorporate work conducted by multiple developers on the same project.

Most developers will tell you that any manual task, is going to be error prone, and the manual based task of copying files was indeed very error prone!

Over the years there have been several advancements in version control systems, currently the most popular one among developers has become Git which is a distributed version control system for tracking changes in source code during software development. It has been specifically been designed for coordinating work among programmers, but can also be used to track changes to any set of files!

One of the advantages offered by git, is that every git directory on every computer is a full-fledged repository with a complete history and full version-tracking abilities independent of network access or a central server. Git is also free and open source.

Central Version Control Repositories

When working with git you will often need a central repository that will act as a source of truth for all developers to to sync up to. In most cases this may be a Cloud-based service such as GitHug, GitLab, BitBucket or a private server on the internet. Whichever one your team uses, the role of this cnetral repository is to provide your team with a Remote centrally located server for your team to Push and Pull changes to source code.

Software teams owe the introduction of easy to manage pull requests to Git.

What are Pull Requests

Pull requests are requests created by a software developer to combine changes they created with the main project. The process includes reviewing those changes. Reviewers can insert comments on code they think could be improved, changed, removed as unnecessary.

After receiving feedback, the creator can respond to it, either by creating a discussion, or simply follow it and change their code accordingly.

What are the benefits of version control systems

One of the biggest benefits of version control systems is that they dramatically reduce risks of developers losing or corrupting source code. It also helps developers to collaborate with each other more efficiently and effectively. By enabling developers to quickly and easily share code.

There are some a number of additional benefits of using Version Control systems, however I will discuss just 2 of the most important aspects.

  1. Branching and merging

    Having team members work concurrently is of fundamental importance, however even lone individuals can benefit from the ability to work on independent streams of changes.

    Creating a "branch" in VCS tools keeps multiple streams of work independent and separate from each other while also providing the facility to merge that work back together, enabling developers to verify that the changes on each branch do not conflict.

    Many software teams adopt a practice of branching for each feature or perhaps branching for each release, or both. There are many different workflows that teams can choose from when they decide how to make use of branching and merging facilities in VCS.

  2. Traceability.

    Being able to trace each change made to the software and connect it to project management and bug tracking software such as Jetbrains Space, and being able to annotate each change with a message describing the purpose and intent of the change can help not only with root cause analysis and other forensics.

    Having the annotated history of the code at your fingertips when you are reading the code, trying to understand what it is doing and why it is so designed can enable developers to make correct and harmonious changes that are in accord with the intended long-term design of the system. This can be especially important for working effectively with legacy code and is crucial in enabling developers to estimate future work with any accuracy.