Conducted by the software developers themselves, rather than the quality assurance (QA) team, unit testing has become far more than a “nice to have” element of the software development lifecycle (SDLC). Now, technology professionals everywhere recognize the importance of this critical phase in ensuring the quality of software of all types.
The good news is that for several decades, software professionals have had the option of automating unit testing, making it more efficient and less time-consuming.
Unit testing must be a requirement for all software developers, helping them ensure the accuracy of their code early on in the SDLC. So, how do you find someone equipped with the skills to perform it?
What is unit testing?
Through unit testing, the software developer tests tiny pieces of code — units — in complete isolation from the rest of the product. This allows the developer to see whether and how that unit is functioning independently of the larger system. It’s a type of testing that occurs early on in the SDLC, prior to later rounds of QA testing. Usually, it’s performed by the developer, as opposed to QA testers.
Developers perform unit testing to spot defects before they escalate and interfere with the system later on in the process. It also gives the developer a sense of how the code operates in different circumstances.
What is test-driven development?
Test-driven development (TDD) reverses the software development process by beginning the development phase with testing, rather than saving all testing until after coding. The approach means that developers use test cases to validate the code and identify problems as early as possible. They keep scripting test cases until they can enable the code to successfully pass.
Essentially, this approach is a form of unit testing. It, too, allows the developer to test code in isolation.
Manual vs. Automated Testing
The advent of automated testing changed the way all testing, including unit testing, is performed. Rather than having to do it manually — or entirely performed by a human being — professionals can create test cases to automate the work, allowing the developers and QA analysts to free up time and effort.
Most unit testing is automated, although there may be cases in which manual manipulation is required.
Interview Questions
Why is unit testing important?
Unit testing has become pivotal to the SDLC. When components or units are tested in isolation, software developers can better understand how the code behaves and validate its quality. It also allows developers to spot issues early on so they can fix them before they affect the entire product when it’s more difficult to fix them. This saves both time and money.
In addition, unit testing helps:
- Ensure code accuracy
- Documentation efforts
- Simplify the entire development process
- Facilitate integration
- Improve performance
What does a good unit test look like?
An ideal unit test should:
- Be automated
- Be reproducible
- Be fast and efficient
- Run in memory
- Remain independent from outside factors in full isolation
- Not cause side effects
- Be descriptive
- Be easy to maintain
- Produce consistent results
- Run in any particular order within the sequence of other tests
- Be readable
What does AAA mean?
AAA means arrange, act, and assert. The pattern is a unit-testing standard that says that developers should separate their testing strategy into these 3 sections. Each of the arrange, act, and assert aspects is only responsible for that particular section. Ultimately, the AAA pattern helps make tests more readable.
What is JUnit?
JUnit is an open-source unit testing framework specifically intended for testing Java code. It’s often used as part of test-driven development, encouraging developers to test prior to coding. It helps facilitate a smoother code-writing process.
What are some other tools used in unit testing?
Unit testing frameworks and tools help developers script and conduct unit tests, facilitating a more efficient, productive, and smoother process. Common tools include:
- ABAP Unit
- Embunit
- Emma
- HtmlUnit
- Jasmine
- JMockit
- JTest
- Karma
- Microsoft Unit
- Mocha
- NUnit
- Parasoft
- PHPUnit
- SimpleTest
- TestNG
- Typemock
- Unity
What’s the difference between unit testing and integration testing?
Unit tests and integration tests are 2 important parts of the SDLC and quality assurance processes. However, they aren’t the same thing. Some key differences are:
- Unit testing is conducted by developers, while integration testing is conducted by QA testers.
- Unit testing occurs early on in the SDLC, while integration testing occurs before the comprehensive testing but after the unit testing.
- Unit testing concerns individual units of code, and integration testing combines components and assesses units tested as a group.
- Unit testing is white-box, and integration testing is black-box.
Job Description
We are looking for a driven, experienced software developer to join our team. You will conduct a range of activities within the software development lifecycle, including conceptualizing and building software, gathering requirements, and conducting unit testing, among other efforts. You will also be responsible for correcting bugs and generally delivering high-quality software.
Responsibilities
- Gather and research requirements
- Work collaboratively with the software development and quality assurance team
- Plan and conduct unit testing, using frameworks and additional tools
- Identify and correct bugs
- Ensure quality and consistency of all software
- Develop best practices for the SDLC
- Work in an agile environment
- Create documentation
Skills and Qualifications
- At least 6 years of experience as a software developer
- At least 5 years of experience with unit testing
- Knowledge of unit testing tools, such as JUnit
- Knowledge of programming languages, including Java, JavaScript, Python, C, and C++
- Experience working in an agile environment
- Experience working in a TDD environment
- Strong collaborative, written, and verbal communication, problem-solving, and analytical skills
- Bachelor’s degree in computer science or a related field
