Unit testing is unimportant to black box testers. Their primary objective is to validate the application against the requirements without delving into implementation details. Have you ever wondered, as a curious or out-of-the-box thinker, how developers test their code? What method do they use to test the code before releasing it for testing? What role does dev-testing play in an agile process? Unit testing is the solution to all of this. I would like to educate you on the importance of unit testing so that development and testing teams can collaborate more effectively to design, test, and release an excellent application. Who knows, maybe some of you will switch to white box testing and use these code validation and improvement techniques in the future!
In this article:
- What is Unit Testing?
- How does Unit Testing Work?
- What are the benefits of Unit Testing?
- Unit Testing Disadvantages
- What Makes a Good Unit Test?
- Unit Testing Frameworks
- Why Unit Testing Matters?
- Unit Testing Best Practices
- Best tools for Unit Testing
- Test Driven Development (TDD) & Unit Testing
- Unit Testing Myth
What is Unit Testing?
Unit testing is a sort of testing in which individual software modules or functionalities are analyzed. Its major objective is to verify the functionality of each unit or function. A unit is the smallest component of an application that can be tested. It often contains only one or a few inputs and outputs a single value. A unit is referred to as an individual program in procedural programming, but object-oriented programming languages include Base/Superclass, abstract class, and Derived/Child class. Frameworks for unit testing, drivers, stubs, and mocks objects are all used in unit testing. It is based on the White box approach. With Unit Testing, Enterprises can:
- Improve Quality of Code
- Build Reusable and Reliable Code
- Simplify Documentation
- Enable Seamless Integration
Unit Testing in SDLC
For Unit testing, developers utilize manual or automated tests to make sure that each unit in the software meets the user’s requirement. This unit can be an individual object, function, method, procedure, or module in the system under test. Writing unit tests to test the individual units makes writing all-inclusive tests simpler as all the units are combined. During software development, it is done as the first level of testing.
Significance of Writing Unit Tests
Unit testing is utilized to create robust software components that aid in code maintenance and the elimination of bugs in code units. We all know about the importance of detecting and correcting defects early in the software development cycle. This testing accomplishes the same thing. It is a mandatory step in the agile software development process. The unit test suite should be run, and a report should be generated when a nightly build is run.
If we made this a standard procedure, many defects would be discovered early in the development cycle, saving us a lot of testing time. I know that many developers despise writing unit tests. Due to deadlines or a lack of seriousness, they either ignore or write bad unit test cases (yeah, they write empty unit tests, so 100% of them pass successfully ;-)). It is critical to write good unit tests or not write any at all. It is even more critical to provide adequate time and a supportive test environment for genuine benefits.
Unit Testing Methods
It can be performed in 2 ways :
- Manual Testing
- Automated Testing
Manual testing involves the tester manually executing test cases without the use of an automation tool. Each stage of the test is carried out manually in this case. Manual testing is time-consuming, especially for repetitive tests, and it takes more effort to create and execute test cases. Manual testing doesn’t necessitate the use of any type of testing tools. It is true that complete automation is not possible, and thus some level of manual testing will always be required.
Software testing automation tools are used in Automated Testing to automate tests and test cases. These tools can enter test data into the system being tested, compare expected results to actual results, and generate reports automatically. The inaugural cost of setting up test automation tools, on the other hand, is high.
How does Unit Testing Work?
Mocks are required to accomplish this. Is it necessary to use mocks when testing functions? Yes, functions cannot be unit tested unless mocks are created. Mock objects work as the foundation for testing. Mock objects are utilized to fill in for missing program components. For example, there could be a function that requires variables or objects that have not yet been created. Mock objects were created to test the function. In such cases, mock objects fill in the gaps. Unit Testing Techniques:
It is known as glass-box testing/transparent testing. The tester is aware of internal functionality in this type of testing. The internal structure of a testable item or function is unknown.
It is a kind of testing where the tester is unaware of a system’s internal functionality. The internal structure of the to be tested function is unknown.
It’s known as semi-transparent testing. It’s a hybrid of Black Box testing and White Box testing. It is a type of testing in which the tester is aware of the internal functionality of a method or unit but not at a deeper level, as in white box testing. In this case, the user is only partially aware of a system’s internal functionality. The following are the various types of testing covered by Gray box testing:
- Matrix testing.
- Pattern Testing.
- Orthogonal Pattern testing.
- Regression Testing.
What are the benefits of Unit Testing?
- The process becomes more agile: To add new functions or features to existing software, we must modify the existing code. However, making changes to previously tested code can be risky and costly.
- Code quality improves: When unit testing is performed, the code’s quality improves automatically. Bugs discovered during this phase of testing are fixed before they are sent to the integration testing phase. As a result, developers write test cases after first understanding the specifications, resulting in robust design and development.
- Detects bugs early: When developers run unit tests, they detect and resolve bugs early in the software development life cycle. This includes specification flaws or missing parts, as well as bugs in the programmer’s implementation.
- Easier changes and integrations: Unit testing makes it simple for the developer to restructure, change, and maintain the code. It also makes it easy to test the code after it has been integrated. Fixing a problem in Unit Testing can prevent many other problems from occurring later in the development and testing process.
- Documentation availability: Developers who are investigating the functionality at a later stage can refer to the unit testing documentation and quickly locate the unit test interface, and correct or work quickly and easily.
- Simple debugging process: It aids in the simplification of the debugging process. If the test fails at any point, the code must be debugged before the process can continue without interruption.
- Lower cost: Bugs are detected and resolved during unit testing, which reduces cost and development time.
- Unit tests can be used to demonstrate code completeness: In the agile process, this is more useful. Until integration is complete, testers do not receive functional builds to test. Code completion cannot be justified by demonstrating that you wrote and tested the code. Running Unit tests, on the other hand, can demonstrate code completeness.
- Save development time: While code completion may take longer, overall development time can be reduced because of fewer bugs in the system and acceptance testing.
- Code coverage can be determined.
Unit Testing Disadvantages
- It is unrealistic to expect unit testing to catch every error in a program. Even in the simplest programs, it is impractical to evaluate all execution paths.
- Unit testing, by definition, focuses on a single piece of code. As a result, it cannot detect integration or system-wide errors.
- Unit testing should be used in conjunction with other testing activities.
What Makes a Good Unit Test?
Well, I’m not the best person to tell you what makes a good Unit Test, but I can tell you the characteristics of a good Unit Test based on my observations on various projects. Poorly written unit tests add no value to the project. Instead, by writing and managing poor Unit Tests, project costs skyrocket.
How to write good Unit Tests?
- Unit tests should be written to validate a single unit of code rather than the entire integration.
- Small, isolated unit tests with clear naming would make writing and maintaining them a breeze.
- If the unit tests are isolated and written for a specific unit of code, changing to another part of the software should have no effect.
- It should run faster.
- Unit test should be exploitable.
Unit Testing Frameworks
Unit testing frameworks are mostly used to aid in the quick and easy creation of unit tests. With an inbuilt compiler, most programming languages do not support unit testing. Unit testing can be made even more enjoyable by using third-party open source and commercial tools.
Unit Testing tools for different programming languages:
- Java framework – JUnit
- PHP framework – PHPUnit
- C++ frameworks – UnitTest++ and Google C++
- .NET framework – NUnit
- Python framework – py.test
Misconceptions and Truths
- It takes longer to write code with unit test cases, and we don’t have time for that – in reality, it would save you time in the long run.
- Unit testing will find all bugs – No, it will not, because the purpose of unit testing is to develop robust software components that will have fewer defects in the later stages of SDLC.
- 100 per cent code coverage equates to 100% test coverage – however, this does not guarantee that the code is error-free.
How to Accept Unit Testing?
A good unit test can be broken down into three parts.
- Create unit test codes.
- Check to see if the unit test code meets the system requirements.
- Execute the software code to check for errors and to see if it meets the system requirements.
Following the completion of the preceding three steps, if the code appears to be correct, the unit test is said to have passed. The test fails if it does not fulfil the system requirements. The developer must recheck and correct the code in this case. To perform testing more accurately, it may be necessary to separate the code in some cases.
Why Unit Testing Matters?
It is a type of testing that accelerates testing. Unit testing aids in the maintenance and modification of code. Any defect revealed after code changes will be revealed if good unit test cases are written for code and run every-time code changes. Codes should be written in a more reusable manner; by doing so, more unit testing will be possible. Writing test cases takes time, but this is offset by the shorter time it takes to run the tests.
Unit tests are more reliable, and in the long run, development will be faster. It simplifies debugging. When a test fails, only the most recent changes must be debugged. Changes made over many days/weeks/months must be scanned or detected when testing at a higher level or phase. The cost of fixing detected bugs during testing is lower than the cost of fixing defects at higher levels. Compare the cost of fixing a defect when a bug is discovered during a phase of unit testing with the same bug discovered during User Acceptance Testing. The effort needed to detect and fix defects discovered during Unit Testing is less than that required to find and fix defects discovered during System Testing or Acceptance Testing.
How to adopt Unit Testing?
Unit test cases were created to accomplish this. Unit test cases are automated, but they are still created by hand. To perform Unit Testing using an automated approach, the following steps must be taken into account: To test a function, add another section of code to your application. This section of code was eventually removed to test code when an application is finished or in a working state.
Code isolation involves isolating a function in order to test it more thoroughly. Isolate code to improve Automated Unit Testing. Isolating functions. It assists in revealing dependencies between code functions. Create automated test cases using the Test frameworks. During test case implementation, the framework displays logs for failed tests cases. Many frameworks now automatically flag and report failed test cases in summary. Depending on the failure, subsequent testing may be halted.
Unit Testing Best Practices
There is no need to write test cases for every scenario. Instead, concentrate on tests that have an impact on the overall system’s behavior. Before you fix a bug, create a test that exposes the flaws.
- If the bug is not properly cached, it will reoccur.
- Comprehensiveness of test suites should be increased.
- Before you fix the defect, write test cases.
- Create test cases that are independent of one another.
- The most important aspect of Unit Testing is to cover all of the paths; however, it is also necessary to pay attention to loop conditions.
- Write cases to verify behavior, as well as test cases to ensure the code’s performance.
- Run test cases on a regular and continuous basis.
Consider the following criteria when writing the optimal code for this testing:
- The code should be robust: In some cases, if the code is defective, the test will fail or, in the worst case scenario, will not be conducted at all.
- Reasonable and understandable: The code should be easier to comprehend. This simplifies the developer’s work of writing the code, and it also simplifies the debugging process for subsequent developers.
- Should be a solitary case: Multiple-case tests are difficult to work with. Thus, writing single-case code is a great practice because it simplifies the code’s comprehension and debugging.
- Allow automated tests: Developers should ensure that automated tests are available.
Moreover, the following points should be put into consideration:
- Instead of writing test cases for every possible situation, focus on the one that affects the system’s behavior.
- There is a chance that the bug will recur because of the browser’s cache.
- Test cases should not be dependant on one another.
- Take note of the loop condition as well.
- Develop test cases on a more frequent basis.
Best tools for Unit Testing
|Jtest||Parasoft Jtest is an integrated development environment (IDE) plugin that leverages an open-source framework (JUnit, mockito, PowerMock, and Spring) to generate, scale, and maintain unit tests. By automating time-consuming Unit Testing tasks, it enables developers to focus on business logic and produce more relevant test suites.|
|JUnit||It is a free tool for the Java programming language. Additionally, it supports assertions for identifying test methods. JUnit is a test run development tool that validates data before it is entered into a piece of code.|
|NUnit||It’s used as a testing framework, and this tool is used for everything. Languages of the internet It is an open-source tool for manually writing scripts. NUnit supports parallel data-driven tests.|
|JMockit||It’s a free and open-source testing tool. JMockit is a tool for code coverage. It aids in API mocking by recording and verifying syntax. It’s a tool that provides path coverage, line coverage, and data coverage.|
|EMMA||It is a free and open source toolset for evaluating and reporting on Java code. EMMA supports the following coverage types: method, line, and basic block. It’s a Java-based application.|
|PHP Unit||It is a PHP language testing tool. It divides the code into distinct units and tests each unit independently. This testing tool makes assertions about how the system should operate in a particular way using pre-defined assertion techniques.|
Test Driven Development (TDD) & Unit Testing
Unit testing is a significant part of TDD since it makes full use of testing frameworks. To achieve automated unit tests, a unit test framework is utilized. While unit testing frameworks are not exclusive to TDD, they are critical components of it. The following sections discuss some of the benefits that TDD provides to the world of unit testing:
- Before the code is written, tests are written.
- Make use of testing frameworks
- Each tutorial in the applications is validated.
- Integration is made simple and straightforward.
Unit Testing Myth
The truth is that unit testing accelerates development. Because programmers believe that Integration Testing will capture all issues, they skip running unit tests. Once units are integrated, very simple issues that could have been detected and repaired very quickly during unit testing take an inordinate amount of time to trace and fix.
What is Source Code?
The source code is a set of human-readable instructions that a programmer creates when constructing a software—often in a word processing tool. A compiler is used to convert the source code to machine code, often called object code, which a computer can comprehend and execute. Because object code is mostly composed of 1s and 0s, it is not human-readable.
What Is Code Refactoring?
In software engineering, code-refactoring is the process of reorganizing source code in order to improve its internal structure and non-functional aspects. Simultaneously, its exterior behavior stays unaltered.
The primary goal of code refactoring is self-explanatory – to make the code more clean, tidy, efficient, and maintainable. This is a type of software upgrade that is required to improve numerous non-functional characteristics, including maintainability, performance, security, and scalability.
What is Functional Testing?
FUNCTIONAL TESTING is a subset of software testing that verifies the software system’s functionality against the functional requirements/specifications. Functional tests are used to validate the functionality of a software program by giving adequate input and comparing the output to the functional requirements. Functional testing is primarily concerned with black box testing and is unconcerned with the application’s source code. This testing validates the Application Under Test’s user interface, APIs, database, security, client/server communication, and other functions. Testing can be performed manually or automatically.
What is Load Testing?
Load testing is a kind of performance testing in which the system’s response is determined under a variety of load scenarios. Load tests are conducted under normal and peak load circumstances.
Approach to Load Testing:
- Evaluate acceptance criteria for performance
- Recognize key situations
- Create a workload model
- Determine the desired load levels.
- Create the tests
- Carry out tests
- Examine the Results