Unit Testing in 2022: Your assertive defensive way to do software testing!

In an agile process, unit testing is an out-of-the-box approach that is assumed by the software development team to test codes before releasing them. Unit testing is what makes dev testing intact in an agile process.

If you want to develop applications with an edge, then the development team and the testing team have to work collaboratively and for this unit testing is inevitable.

What is unit testing?

Unit testing is a type of testing that primarily tests the smallest testable part of an application- a unit or an application- in software. The unit can be a function, an object, a method, a procedure, or a module in software that is being tested. By processing multiple inputs, it generates a single output. Unit testing is referred to in different ways in different contexts which means in procedural programming, a unit is termed as an individual program whereas, in object-centric programming, it is referred to as Base or Superclass, Abstract Class, Derived or Child class, etc. Unit testing has a ground-rule which means, it works concerning the white box technique, and it best tests frameworks, drivers, stubs and mocks to test software units.

Unit testing is beneficial in several ways. It can improve the quality of a code, support the reusability and reliability of a code, ease documentation, enable hassle-free integration alongside other benefits.

In SDLC, unit testing is carried out by developers to ensure whether software units meet the customer requirements justly.

How can you streamline unit testing?

When unit testing goes wrong, it can cost your project a certain cost, time, and effort wastage. Based on our certain previous experiences, we believe the following is one checklist that you can follow to ensure that your unit testing is streamlined:

• Do not test integrations, but test a single unit of code using unit testing
• For easy writing and maintenance, go for small and clear unit tests with clear labels.
• If a unit test is intended for a specific unit of code, it should not get affected once moved to another part of the software. 
• Unit tests should be quick and reusable

What are the objectives of unit testing?

Unit testing is carried out with the following objectives:

• Isolating a section of code.
• Verifying code correctness.
• Testing of every function and procedure.
• Saving costs by identifying and fixing bugs early in the development cycle.
• Assisting developers in identifying codebase quickly and enabling them to make necessary changes as quickly as possible.
• Helping in code reuse.

Which are the best practices in unit testing?

Every condition need not have a test case, but it is important to ensure that the tests do not affect the system as a whole. Make sure that before bug fixing, you note down the test that exposes the defects. Here are some of the best practices in unit testing:

1. Write strong codes, broken codes can fail your tests or in the worst case, fail to execute.
2. Write understandable codes for making debugging easy for developers.
3. Single cases are more understandable and easily debuggable than multiple cases.
4. Automate tests and make sure of continuous delivery and integration.
5. Give priority to test cases that affect the system behavior and not for all conditions.
6. Make sure that your test cases are not interdependent.

Note: For instance, say you have a database-dependent code instead of writing a case to test a class, create an abstract interface around that database and implement an interface with a mock 0bject.

1. Apply loop condition for test cases and be certain that it covers all the paths.
2. Go for frequent and continuous test cases.
3. Cache appropriately or else the bug will reappear. 
4. Make your test suites more comprehensive.
5. Before fixing defects, write the test cases.
6. Test cases should verify behavior and it should also ensure code performance.

A briefing on best tools used for unit testing:

JTest: It is an automated JS software and static analysis tool for unit test case generation and execution. It concentrates on business logic and facilitates meaningful test suites. 

JUnit: It is a free tool used for Java programming language and favors assertions to identify test methods. It tests data first and inserts it into a code.

NUnit: It is an open-source testing framework applied for all .NET languages for writing scripts manually. It also supports parallel data-driven tests. 

JMockit: An open-source testing tool, JMockit is a code coverage tool for mocking API with recording and syntax authentication. It facilitates line coverage, path coverage, and data coverage.

EMMA: EMMA is an open-source testing framework for analysis and report of Java-based languages that supports method coverage, line coverage, and basic block coverage.

PHPUnit: It is a unit testing tool for PHP language that uses predefined assertions to make the software system behave in a predetermined manner.

Summary of unit testing tools based on programming languages:

• Java: JUnit
• PHP: PHPUnit
• C++: UnitTedt++ and Google C++
• .NET: NUnit
• Python: py.test

Conclusion

If your software development demands testing to test every function individually, then unit testing must come into your purview. Unit testing is always preferable for software development as it considerably reduces the time and cost consumed for detecting and fixing bugs by regularly testing the functionalities, which otherwise would happen only in the later stages of software development.

Unit testing, like any other testing framework, has certain disadvantages. However, with consistency and stringent steps assumed during the software development stages, these demerits can be overcome.

In short, we can assure you that this kind of testing done on each functionality saves your time and cost. If you go for acceptance testing, then the cost incurred will be more than the unit testing approach. While testing your software product, it is best to create mock objects for satisfying the dependency of a specific method or function.