Understanding Branch Coverage in Software Testing
Tags: testing, webdev, javascript, beginners
Published: 2024-02-20 14:55:00

## Introduction

Branch Coverage is a popular testing technique that provides insights into the percentage of branches executed during testing.

In this article, we'll explore what is Branch Coverage, Its importance, How it works, and many more!

So Without delaying further, let's Start!

## What is Branch Coverage?

![black flat screen computer monitor](https://images.unsplash.com/photo-1607798748738-b15c40d33d57?q=80&w=1000&auto=format&fit=crop&ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D)

Branch coverage is a white box testing technique to measure which branches (decision points) in a program's code have been executed during testing.

A “branch” is one of the possible execution paths the code can take after a decision statement—e.g., an **if** statement—gets evaluated.

> Formula of Branch Coverage:
> 
> **Branch Coverage (%) = (Number of Functional Flow Implemented & Tested)/ (Total Number of Success & Fail Conditional Flow) \* 100**

A program with high test coverage is more likely to have fewer bugs compared to a program with low test coverage.

Let's Understand that with an example,

```javascript
  if (condition1) {
      if (condition2) {
          // block 1 
      }
  } else {
      // block 2  
  }
```

There are 4 possible branches here:

1. condition1 and condition2 are true -&gt; block 1 executes
    
2. condition1 is true but condition2 is false -&gt; block 1 does not execute
    
3. condition1 is false -&gt; block 2 executes
    
4. condition1 and condition2 are false -&gt; block 1 does not execute
    

To achieve 100% branch coverage, we need test cases that execute all 4 paths.

## How does it work?

![black flat screen computer monitor](https://images.unsplash.com/photo-1607706189992-eae578626c86?q=80&w=1000&auto=format&fit=crop&ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D)

Branch coverage works by analyzing the flow of control in a program. Here are the steps:

1. Firstly, we identify the branches in the code.
    
2. During the Testing phase, It uses tracking to see which paths the program takes during tests.
    
3. Now the Test cases are run on the instrumented code.
    
4. After the test execution is complete, the tool collects data on which branches were executed and how many times.
    
5. With that data, the branch coverage percentage is calculated using the formula (mentioned before).
    

## Why it's Important?

Branch coverage is an important software testing metric. It has many benefits, Here are some of them:

* It helps us to find which branches are not tested. So, we can easily fix potential bugs.
    
* High branch coverage states that most of the code has been tested which also indicates that our code is more reliable.
    
* It reduces the likelihood of edge-case defects
    
* It improves the maintainability of the code.
    

## Conclusion

If you found this blog post helpful, please consider sharing it with others who might benefit. You can also follow me for more content on Javascript, React, and other web development topics.

To sponsor my work, please visit: [**Arindam's Sponsor Page**](https://arindam1729.hashnode.dev/sponsor) and explore the various sponsorship options.

Connect with me on [**Twitter**](https://twitter.com/intent/follow?screen_name=Arindam_1729), [**LinkedIn**](https://www.linkedin.com/in/arindam2004/), [**Youtube**](https://www.youtube.com/channel/@Arindam_1729) and [**GitHub**](https://github.com/Arindam200).

Thank you for Reading :)

![Thank you Image](https://cdn.hashnode.com/res/hashnode/image/upload/v1701878425408/cfeb93d1-8745-43a1-8667-42e03aa41350.png)