Regression vs Unit Testing_ A Comprehensive Guide.pdf

Unit testing focuses on validating the smallest testable parts of an application, typically individual functions, classes, or modules, to ensure each component performs as intended.

1. Regression vs Unit Testing: A
Comprehensive Guide

Testing is pivotal in the Software Development Life Cycle (SDLC). Ensuring the seamless
functionality of every software component is imperative to meet both business and user
expectations. Amid the diverse array of tests and testing methodologies, it's not uncommon for
regression testing and unit testing to be conflated, leading to confusion. Distinguishing these
two vital testing types is paramount for the success of the SDLC and, ultimately, for delivering
high-quality software. This blog delves into the essential details, advantages, and key distinctions between regression
and unit testing to shed light on their unique roles in software development.
Understanding Regression Testing
In the world of software development, haste is seldom advisable. Every step and process holds
significance; none can be overlooked.
Regression testing adopts an intuitive approach to evaluating software products. Typically
conducted before or after system modifications, it is a versatile solution for addressing various
software glitches. This is where regression testing intersects with unit testing.

2. While unit testing focuses on isolated components, regression testing is performed with other
critical test cases. It is indispensable and beneficial for any system. Neglecting it can lead to
significant setbacks for a company or enterprise.
For instance, consider designing a sign-in page for an online shop. Users must access it using
their credentials, which can make them vulnerable. Regression testing is pivotal in addressing
issues like cyberattacks gaining unauthorized access or legitimate users facing restrictions.
Regression testing ensures the security and functionality of the feature and other interconnected
components, safeguarding users from potential disruptions.
Regression Testing Techniques
1.​Complete Retest: This technique is the go-to when substantial changes are required in
your application's core code. It thoroughly examines all components, encompassing any
recent software alterations. While comprehensive, it's also resource-intensive and
time-consuming. Reserve this method for in-depth regression testing. 2.​Selective Regression Testing: This technique comes into play when dealing with minor
software alterations. It allows you to focus on a specific module with limited changes.
With this approach, you can assess how the existing software behaves with newly added
or removed features while maintaining a history of test results. 3.​Prioritization of Test Cases: Ideal for regression testing, this technique prioritizes test
cases based on their criticality and risk to the product. High-priority cases take
precedence, followed by medium and low-priority ones. This method ensures that the
most critical aspects are thoroughly examined first, streamlining the testing process.
Exploring Unit Testing
Unit testing is a critical practice in software development, focusing on evaluating the source
code early in the development life cycle. It involves scrutinizing individual units of code to
ensure high-quality programming. As this test type delves into the internal workings of the
software, it falls under the category of white-box testing. Traditionally, software developers were
primarily responsible for conducting unit tests within companies due to their familiarity with the
codebase. Since its scope is limited to a specific portion of the code, unit testing is quick and
straightforward. Moreover, it plays a vital role in cost reduction by addressing defects and bugs
in the early stages of development when the cost of rectification is considerably lower compared
to later stages.
An additional advantage of unit testing is its automation, making it an efficient and reliable
testing methodology. This practice is fundamental, especially for teams following agile
methodologies, enhancing programming efficiency and ensuring the development of robust
software products.

3. Unit Testing Techniques
1.​Black Box Testing: Commonly referred to as Behavioral testing, Black Box Testing is
centered on software requirements and specifications. It emphasizes the application's
input and output without delving into its internal code implementation. It symbolizes the
software system being tested, and testers execute evaluations based on provided inputs
and expected outcomes.
2.​White Box Testing is an internal approach to enhance security, usability, and design.
Testers have visibility into the code during this testing type, allowing them to verify the
input-output flow and understand the software's internal structure. The name "White
Box" originates from this ability to perceive the software's inner workings, providing
insights into its architecture and logic.
3.​Gray Box Testing: Gray Box Testing balances Black Box and White Box Testing
methodologies. It seeks to identify defects that might arise if the code structure isn't
functioning as intended. Testers possess some knowledge about the application's
internal structure, enabling a combined approach that harnesses the benefits of both
black-box and white-box testing. This fusion enhances the testing process and
contributes to an overall improvement in product quality.
How Regression Testing and Unit Testing Are Applied
Understanding the distinctive use cases of regression and unit testing is vital, considering their
theoretical similarities often blur the lines between them. Despite seeming akin, they serve
unique purposes, acting as proactive security measures in software development to preempt
potential issues.
Applications of Regression Testing
●​Malfunction Resolution: Utilized when a system reports a malfunction or code
interruption, ensuring written code integrity.
●​Conversion Test Method: Moving the program to a different environment and validating
accurate integration, primarily focusing on modifications in the new environment.
Applications of Unit Testing
●​Mock Object Utilization: Verifying specific parts of code absent in the main program by
using mock objects, ensuring comprehensive code coverage.
●​Continuous Code Validation: Performing unit tests during code writing, aiding in early
error detection and seamless integration of new components.
Distinguishing Regression and Unit Testing
Understanding the differences between regression testing and unit testing is paramount for
maintaining the robustness of any software. Although both serve the purpose of vulnerability

4. scanning to detect threats, they vary in terms of their test objectives, stages in the development
process, and the scope of the code they cover. Let's delve into these distinctions to grasp their
roles better.
Difference in Test Objectives:
●​While similar, Unit and regression testing have distinct targets within your code. Unit
testing, conducted by programmers, assesses individual components, validating the
correct functionality of each variable, function, and object.
●​On the other hand, regression testing (often termed QA testing) occurs after
programmers complete work on specific features. It acts as a system-wide check,
ensuring untouched components function as expected. While unit tests provide the
precision of individual functions and variables, regression tests collaborate to ascertain
that the entire system functions optimally.
Difference in the Development Phase:
●​The timing of unit and regression tests sets them apart. Unit tests are conducted during
the development phase, where developers run them after implementing changes to
confirm no adverse impacts.
●​Conversely, regression testing is performed before the feature's production release. It
comprises unit tests, integration tests, and various other testing types. Testers are
responsible for executing regression testing. Automated regression testing, a key step in
continuous integration/continuous delivery, quickly detects if recent code changes have
disrupted the existing code.
Difference in Code Coverage:
●​A unit test concentrates on a single unit, method, or function, examining one element at
a time. It doesn't account for how these units interact, necessitating integration tests.
This approach provides swift feedback due to its focused testing nature.
●​In contrast, regression tests validate if alterations to existing functionalities have affected
other parts of the system by testing against predefined scenarios, ensuring correct
integration of units. Given the comprehensive testing involved, it generally consumes
more time.

5. What Tools Facilitate Regression and Unit Testing
Regression Testing Tools
●​Selenium: A widely recognized framework for web applications, Selenium supports
multiple programming languages like C#, Java, and Python. It excels in automating web
browser tests, ensuring validation and reliability. Selenium is praised for its high code
readability, code reusability, and cost-effective script maintenance. ●​Testsigma: An automation testing platform leveraging Natural Language Processing
(NLP), Testsigma enables seamless automation of tests across web, mobile, desktop,
and APIs. Its user-friendly interface allows for test automation with the ease of crafting
sentences in English. ●​UFT testing (Quick Test Professional - QTP): Renowned for its activity recorder
feature, UFT testing allows users to record user actions and transform them into scripts,
streamlining the testing process effectively.
●​Subject7: A cloud-native test automation platform, Subject7 integrates all testing
procedures into a unified platform, facilitating efficient and centralized testing operations.
●​Cerberus Testing: An open-source and low-code test automation platform, Cerberus
Testing offers support for various testing domains, including Web, Mobile, API, Desktop,
and Database testing. It simplifies test automation while ensuring flexibility and
effectiveness.
Unit Testing Tools
●​NUnit: A well-established unit testing tool primarily written in C#, now compatible with all
.NET languages. It offers extensive features, including support for data-driven tests and
various platforms like Silverlight, Xamarin mobile, and .NET core. ●​Mockito: An open-source tool renowned for simplifying the development of testable
applications. Mockito facilitates using external dependencies in code, allowing
developers to create mocks and manage return values and exceptions effectively.
●​Emma: An open-source Java-based unit testing tool ideal for high-scale enterprise
software. What sets Emma apart is its capability to provide code coverage to individual
developers at no cost, promoting fast and effective testing of applications or software.
●​Quilt HTTP: A versatile Java software development tool that is a cross-platform solution.
In unit testing, Quilt HTTP aids in measuring coverage of Java programs, navigating
control flow graphs, and streamlining the reporting process for comprehensive insights.
Streamlining Regression & Unit Testing with HeadSpin's
Advanced Testing Solution
HeadSpin Regression Platform stands as a reliable tool crafted for automated testing of both
web and mobile applications. It aids developers in swiftly identifying and addressing regressions
before the product goes live. The platform integrates with various development tools and

6. supports multiple browsers and operating systems, providing a versatile regression testing
option.
HeadSpin offers valuable insights into software application performance and user experience in
unit testing. Leveraging metrics such as packet-level network data and device KPIs, the
AI-based Platform provides actionable insights for organizations. These insights encompass
issue cards, time series, session videos, and packet-level details, all crucial for enhancing
application performance.
Key Features of HeadSpin's Advanced Testing Solution:
●​Automated Regression Testing: Offers tools and frameworks for automated regression
tests, ensuring rapid retesting of applications after changes or updates without affecting
existing functionality.
●​End-to-end Automated Unit Testing on Real Devices: Enables end-to-end automated
unit testing of software applications and mobile apps, promoting collaboration for product
management and release efficiencies.
●​Parallel Testing: Enables simultaneous testing on different devices or platforms,
significantly expediting the regression testing.
●​Test Reporting and Analytics: Provides comprehensive reports and analytics on test
results, promptly identifying regression issues.
●​Data Science and AI for Root Cause Analysis: Utilizes data science and AI to analyze
degradation across new app builds, OS releases, feature additions, and locations, aiding
in root cause analysis and error resolution.
●​Integration with CI/CD Pipelines: Seamlessly integrates with continuous
integration/continuous deployment (CI/CD) pipelines, automating testing during the
development process and fostering a smooth workflow.
HeadSpin's advanced testing solution enhances efficiency, reduces time-to-market, and ensures
a competitive edge within the dynamic app landscape.
Conclusion
Unit and regression testing are vital pillars in the software development journey. Regular
execution of these tests is key to minimizing bugs and refining code quality.
Regression testing conducted post-unit testing before a software release, ensures system
integrity despite changes. On the other hand, unit testing meticulously validates new functions,
ensuring precise code execution.
HeadSpin employs a data-driven approach, offering regression insights that empower
professionals to monitor and adapt to application changes effectively. With AI-powered
regression intelligence, HeadSpin facilitates insightful comparisons across builds, locations, and
more, further enhancing software development and quality assurance.

7. Article Source:

This article was originally published on:
https://www.headspin.io/blog/gaining-insight-into-regression-and-unit-testing