#unit testing types

Unit testing is a focus on individual software system units or components is known as unit testing. Unit testing checks that each piece of software operates as intended and complies with specifications. Developers often carry out unit testing, which is done before the code is merged and tested as a whole system and is done early in the development process.

Each time the code is modified, unit tests are automatically run to make sure that the new code won't break any functionality already in place. A function or method, for example, can be tested independently from the rest of the system using unit tests, which are created to check the smallest possible unit of code. As a result, early on in the development process, developers may immediately discover and address any errors, enhancing the software's overall quality and cutting down on the time needed for testing.

The phrase "unit testing" has a different connotation in the industry than "system testing," describing a step or activity in the traditional software development life cycle. These phrases don't necessarily refer to automation. Because "customer testing" and "developer testing" are two different sorts of testing, some Agile authors have suggested using the word "developer testing" to avoid any misunderstandings. They also emphasize the diverse roles involved in each type of testing.

Why do unit testing?

Unit testing is the first level of testing carried out before integration and further levels of testing in a testing level hierarchy. It employs modules for testing, reducing the reliance on waiting for Unit testing aided by the usage of stubs, drivers, dummy objects, and unit testing frameworks.

Unit testing, integration testing, system testing, and acceptance testing are the four levels at which software is normally tested.  However, due to time constraints, software testers occasionally skip unit testing, which can result in higher defects during integration testing, system testing, acceptance testing, or even beta testing, which happens after a software application is finished.

Here are a few essential justifications:

Unit testing enables developers and testers to swiftly update code that is producing defects by assisting them in understanding the fundamentals of the program.

It helps to have unit tests for documentation.

There is a chance that there will be fewer flaws in subsequent testing levels because unit testing catches errors relatively early in the development process.

Relocating code and test cases promotes code reuse.

There are three different sorts of unit testing techniques. Those are

Black box testing: This method of testing is used to cover input, user interface, and output unit tests.

White box testing: By providing input and examining the functionality output, including the internal design structure and code of the modules, white box testing is a technique used to test the functional behaviour of a system.

Grey box testing: it is a way for running pertinent test cases, test methods, and test functions as well as for examining the performance of the code for the modules.

Unit testing has the following benefits:

 It enables developers to discover what functionality is offered by a unit and how to utilise it to create a fundamental understanding of the unit API.

The programmer can improve the code and ensure that the module functions properly by using unit testing.

Unit testing enables testing of specific project components without having to wait for others to be finished.

Unit testing contributes to the overall improvement of software quality by ensuring that each unit of code operates as intended and satisfies the requirements.

 Building a fundamental understanding of the unit API enables developers to learn what functionality is provided by a unit and how to use it.

Unit testing allows the programmer to make code improvements and check that the module works as intended.

Specific project components can be tested using unit testing without having to wait for other project components to be done.

Early Issue Detection: By using unit testing, developers can find and fix problems early on in the development process, before they balloon and become more difficult to fix.

By ensuring that each unit of code runs as intended and meets the requirements, unit testing helps to enhance software quality overall.

Increased Confidence: By verifying that each component of the product is operating as intended, unit testing gives developers more assurance in their code.

Unit testing allows developers to validate changes to the code without having to wait for the entire system to be tested, which speeds up development.

to comprehend and maintain the product. This documentation is clear and succinct and describes the code and its behavior. Better documentation is provided by unit testing, which makes it simpler for other developers 

Refactoring is facilitated by unit testing, which gives developers the confidence to make changes to the code without risking the functionality of the program.

Unit testing can cut down on the time and expense needed for subsequent testing.

Unit testing's drawbacks include the lengthy process of writing unit test cases.

Because there is a risk of faults in the modules during integration testing, unit testing won't catch every issue in the module.

Unit testing is ineffective for detecting flaws in the module's UI (User Interface) section.

When the source code is modified regularly, maintenance takes more time.

It is unable to cover non-functional testing criteria like system performance and scalability.

Timing and Work: Making and maintaining test cases for unit testing is a considerable time and effort commitment, especially for complex systems.

Dependency on Developers: For unit testing to be successful, developers must design precise, succinct, and thorough test cases to validate the code.

Testing Complex Units Can Be Tough: Unit testing can be tough when working with complex units since it can be challenging to isolate and test individual units independently of the rest of the system.

Testing Interactions is Difficult: Unit testing, which primarily focuses on individual units, may not be enough for testing interactions between units.

Testing User Interfaces Is Difficult: Unit testing, which usually concentrates on the functioning of individual units, may not be appropriate for testing user interfaces.

Overreliance on Automation: Relying too much on automated unit tests can give developers a false sense of security.