What is Unit Testing?

Unit Testing is not a new concept. It’s been there since the early days of programming. Usually, developers and sometimes white box testers write Unit tests to improve code quality by verifying every unit of the code used to implement functional requirements (aka test driven development TDD or test-first development).

The traditional definition, “Unit Testing is the method of verifying the smallest piece of testable code against its purpose,” is probably familiar to most of us. The unit test is unsuccessful if the goal or criteria is not met.

It basically implies writing a unit test, which is a piece of code, to check the code that was produced to implement the requirements.

Unit Testing in SDLC

To make sure that every software unit satisfies the needs of the client, developers employ either automated or manual tests. The software being tested may use this unit as a single function, object, method, procedure, or module.

Since all the units are combined, it is easier to write thorough tests when unit tests are written to evaluate the individual components. It is carried out as the initial testing step in the software development process.

Importance of Writing Unit Tests

Designing reliable software components that aid in code maintenance and problem-solving inside code units is accomplished through the usage of unit testing. We are all aware of how critical it is to identify and address flaws early in the software development cycle. The goal of this testing is the same.

It is essential to the agile approach of developing software. A report should be generated and the unit test suite should run when a nightly build is executed. The QA team shouldn’t accept that build for verification if any of the unit tests have failed.

If we set this as a standard process, many defects would be caught in the early development cycle, thereby saving much testing time.

I am aware that a lot of developers detest writing unit tests. Because of their busy schedules or lack of seriousness, they either ignore or write poor unit test cases (yes, they write empty unit tests, thus 100% of them pass ;-)). Either writing quality unit tests or none at all is crucial. For genuine benefits, it is even more crucial to offer enough time and a supporting environment.

Unit Testing Methods

It can be performed in 2 ways :

1. Manual Testing
2. Automated Testing

Without the use of an automated tool, the tester manually runs test cases during manual testing. Every test step is carried out manually in this case. Manual testing is time-consuming, particularly for repetitive tests, and it takes more work to develop and run test cases. No testing tool knowledge is necessary for manual testing.

There will always be some amount of manual testing done because it is an inevitability that 100% automation cannot be achieved.

In Automated Testing, Tests and test cases are automated using software testing automation technologies. Your test can be recorded, saved, and replayed as many times as necessary by the automation tool without requiring any additional human involvement.

These tools can even enter test data into the system being tested as well as it can compare the expected results to the actual results and automatically generate the reports. However, the initial cost of setting up test automation tools is high.

Techniques Within Unit Testing

#1) White Box Testing:

In white-box testing, the tester knows the internal structure of the software including the code and can test it against the design and requirements. Hence, white box testing is also known as transparent testing.

#2) Black Box Testing:

In black-box testing, the tester does not know the internal structures or either the code of the software.

#3) Grey Box Testing:

This is also referred to as semi-transparent technique testing which means the testers are only partially aware of the internal structure, functions, and designs along with the requirements.

Debugging is done by actual input from the front-end to get exact data from the back-end. The grey box is therefore considered a combination of black box and white box testing techniques.

Grey box testing covers the following types of testing:

• Matrix Testing.
• Pattern Testing.
• Orthogonal Pattern Testing.
• Regression Testing.

Benefits of Unit Testing

1. The process becomes agile: We must modify the old code in order to add new features or functions to the current software. However, altering the previously tested code might be expensive and dangerous.
2. Code quality improves: When unit testing is done, the code’s quality automatically improves. Prior to being forwarded for the integration testing step, the defects found during this testing are corrected. enables developers to create test cases by first comprehending the specifications, which leads to robust design and development.
3. Detects bugs early: As developers run unit tests, they detect bugs early in the software development life cycle and resolve them. This includes flaws or missing parts in the specification as well as bugs in the programmer’s implementation.
4. Easier changes and simplified integrations: Doing unit testing makes it easy for the developer to restructure the code, make changes, and maintain the code. It also makes testing the code after integration much easier. Fixing an issue in Unit Testing can fix many other issues occurring in later development and testing stages
5. Documentation availability: Developers who are looking into the functionality at a later stage can refer to the unit testing documentation and can easily find the unit test interface and correct or work fast and easily.
6. Easy debugging process: It helps in simplifying the debugging process. If the test fails at any stage the code needs to be debugged or else the process can be continued without any obstacles.
7. Lower cost: Cost and development time are decreased when defects are found and fixed during unit testing. Without this testing, it will be more difficult to identify and fix any flaws that are found later after the code integration, which would increase development time and costs.
8. Code completeness can be demonstrated using unit tests: This is more useful in the agile process. Testers don’t get functional builds to test until integration is completed. Code completion cannot be justified by showing that you have written and checked the code. However, running Unit tests can demonstrate code completeness.
9. Save development time: Code completion may take longer but due to fewer bugs in the System and Acceptance testing, overall development time can be saved.
10. Code coverage can be measured.

Unit Testing Cycle

What Makes a Good Unit Test?

Although I’m not the best person to judge what constitutes a successful unit test, I can identify its qualities based on my observations of numerous projects. Poor unit tests don’t make the project better. Instead, creating and maintaining poor unit tests results in a large increase in project expenditures.

How to write good Unit Tests?

• t is best to write unit tests to check a particular code unit rather than the integration.
• Writing and maintaining small, isolated unit tests with distinct names would be quite simple.
• If the unit tests are isolated and designed for a particular unit of code, switching to a different section of the software shouldn’t have an impact on them.
• It need to operate swiftly.
• Reusable unit tests are ideal.

Unit Testing Frameworks

Unit Testing frameworks are mostly used to help write unit tests quickly and easily. Most programming languages do not support unit testing with an inbuilt compiler. Third-party open source and commercial tools can be used to make unit testing even more fun.

List of popular Unit Testing tools for different programming languages:

1. Java framework – JUnit
2. PHP framework – PHPUnit
3. C++ frameworks – UnitTest++ and Google C++
4. .NET framework – NUnit
5. Python framework – py.test

Misconceptions and Truths

• In actuality, it would reduce your development time over time, but writing code with unit test cases takes more time, and we don’t have that much time.
• All issues will be found by unit testing. It won’t since the goal of unit testing is to create reliable software components that will have fewer flaws in subsequent phases of the SDLC, not to detect faults.
• 100% code coverage equates to 100% test coverage; nonetheless, this does not ensure error-free code.

How to Accept Unit Testing?

Good unit testing can be carried out in 3 basic parts.

1. Write a unit test code.
2. Run the unit test code to see if it meets the system requirements.
3. Execute the software code to test for any defects and see whether the code meets the system requirements.

After undertaking the above 3 steps, if the code appears to be correct then the unit test is said to be passed. If it does not meet the system requirements, then the test fails. In this case, the developer needs to recheck and correct the code.

In some instances, it is necessary to separate the code to perform this testing more accurately.

Best Practice

To create the best code during this testing, consider the following points:

• Code should be strong: There are instances where the test fails or in worst cases does not get executed at all if the code is broken.
• Understandable and reasonable: The code should be easy to understand. This makes it easy for the developer to write the code and even other developers who will work on the code subsequently will find it easy to debug.
• Should be a single case: Tests that define multiple cases in one are complex to work with. Thus, writing a single case code is a best practice, which makes the code easier to understand and debug.
• Allow automated tests: The developers should make sure that the test runs in an automated form. It should be in a continuous delivery or integration process.

Other points to be kept in mind are as follows:

• Concentrate on the test that has an impact on the system’s behavior rather than writing test cases for every condition.
• The browser’s cache may be the cause of a bug recurrence.
• Test cases shouldn’t depend on one another.
• Be mindful of the loop condition as well.
• Create test cases more often.

Conclusion

When it becomes necessary to test each function independently, unit testing enters the picture. Instead of discovering flaws later in the software development process, it is far more logical to locate and address them during this testing, saving time and money.

Although it provides numerous benefits, there are drawbacks to its use.Throughout the software development process, strict discipline and consistency are necessary to get past obstacles and achieve the desired results

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