Unit Testing

Q: What Is Integration Testing?

It is the second phase of the Software Testing Life Cycle (STLC) process and is performed after unit testing. It is a testing method where individual components or units of the application are tested in a group.

Unit Testing vs Integration Testing: An Informative Guide

sitemanager — Thu, 01 Dec 2022 15:00:51 +0000

Table of Contents

What Is Unit Testing?
Why Should One Opt For Unit Testing?
What Is Integration Testing?
What Is The Process Of Integration Testing?
Techniques Of Integration Testing?
Unit Testing vs Integration Testing
When Should Unit Testing Or Integration Testing Be Preferred?
Consequences Of Not Performing Unit And Integration Tests
Conclusion

Software testing techniques are performed to validate the application under test (AUT) against the functional or non-functional requirements. Each type of testing, such as regression testing, performance testing, security testing, software automated testing, etc., ensures that testers identify specific types of defects. Hence, multiple testing techniques are performed to ensure the application meets acceptable quality standards.

What Is Unit Testing?

It is a testing method where the smallest testable element of code, known as a unit, is tested. A unit can be a method, function, subroutine, object, procedure, etc. These individual elements, known as a unit, are tested to ensure they are functioning as expected. Developers are involved in unit tests, and thus early identification of bugs and issues occurs. It is known as White box testing.

Developers use stubs, mock objects, unit testing frameworks, and drivers to perform unit testing. Evidently, the code readability is increased, and code can be reused through the effective conduction of unit testing, which also improves Deployment velocity.

Why Should One Opt For Unit Testing?

The following are four key reasons for performing unit testing in software development:

Enables quick and easy integrations:

Unit testing enables upgrading the entire system libraries and refactoring the application code. The code changes that may not go well with the application’s design can be deciphered, leading to better code maintenance. When bugs are detected in existing functionality, unit testing ensures these bugs are perfectly addressed. When each application unit is thoroughly evaluated and tested, the units integrated later in the software development life cycle become even more accessible.

Reduces development costs significantly:

Unit testing ensures that the time, expense, and other resources used for development are decreased considerably. When the code of a function is written, the bugs are detected and fixed instantly. The time and cost to detect and fix bugs are reduced by correctly applying the unit test method.

Provides effective documentation:

Product findings and implementation process are effectively documented through the unit test methodology. Suppose the team members want to learn about what functionality is provided by one module or another. In that case, the team members can refer to the specific documents to understand the system and the module’s logic. Indicators are represented by unit test cases that carry information about the inappropriate or appropriate use of a software component. Thus, the unit test cases provide perfect documentation for these indicators.

Code coverage is enhanced:

Some developers believe that 100 percent of the code must be covered, while others believe there must be a complete code coverage policy. This scenario depends upon the organization and the project stakeholders. Many tools support unit tests in determining the total percentage for covering the project, function, or separate modules. Knowing whether a particular line will be executed while writing code is essential. Using unit testing coverage metrics, developers can decide whether a code line is necessary.

What Is Integration Testing?

It is the second testing phase of the Software Testing Life Cycle (STLC) process and is performed after unit testing. It is a testing method where individual components or units of the application are tested in a group. Then the application behaviour is verified in terms of performance when integrated. This testing method ensures that defects are exposed during the interaction between units or integrated components.

What Is The Process Of Integration Testing?

Choose the module:

The suitable component or module need to be selected and tested based on the strategy

Perform unit testing:

Unit testing is performed on all the features of the component or module that has been selected

Deploy the module:

Deployment of the chosen components or modules to the required initial fixes is done to get the integration testing running

Perform Functional testing:

All the use cases for the components that have been chosen are tested

Perform Structural testing:

The chosen components are tested by conducting structural testing

Analyze the results:

The results of the testing mentioned above activities are recorded, and the above steps are repeated until the product, application, or system is thoroughly tested.

Techniques Of Integration Testing?

Top-down Integration testing:

It is a testing method where integration testing takes place from top to bottom, based on the software system’s control flow. The testing of higher-level modules takes place first, and then the lower-level modules are tested and integrated to check the software functionality.

Bottom-up Integration testing:

In this testing method, lower-level modules are tested first, and then the testing of higher-level modules is facilitated. The testing process continues until all the top-level modules are tested.

Sandwich/Hybrid Integration testing:

It is a testing method where both the top-level and lower-level modules are tested simultaneously. It combines the functionalities of both top-down integration testing and bottom-up integration testing methods.

Big bang testing:

All the modules are integrated at once in this testing type. After integration, the system is verified to ascertain whether it is working as expected. If the wholly integrated module is identified with a defect, knowing which module caused the issue becomes a cumbersome process. Even if the fault is detected, fixing the same would cost relatively high because the bug was identified later.

Unit Testing vs Integration Testing

Both unit testing and integration testing are forms of functional testing that require coding and testers. Additionally, both types of testing use similar or even the same types of tools. Here are the key differences between unit testing vs integration testing:

Unit Testing	Integration Testing
Tests the single component of the whole system, i.e., tests a unit in isolation	Tests the system components working together, i.e., test the collaboration of multiple units
Unit tests are faster to execute	Integration tests may run slow
There is no external dependency, and all external dependencies are stubbed out	Integration testing requires interaction with external dependencies such as database and hardware
It is a simple process	It is a relatively complex process
Generally performed by developers	Performed by QA team engineers
It is a type of white box testing	It is a type of black box testing
Carried out at the initial testing phase; may be performed anytime later	Integration testing takes place after unit testing and before system testing
Maintenance is cost-effective	Maintenance is relatively expensive
Begins with the module specification	Begins with the interface specification
Unit testing has a narrow scope as it just checks if each small unit or segment of the code is performing as per the expectations	Integration testing has a broader scope as it covers the entire application
Unit testing leads to the detailed visibility of the code	Integration testing leads to the clear visibility of the integration structure
Unit tests only help uncover the issues within the functionality of individual modules and do not validate the integration errors or system-wide problems.	Integration tests help uncover the bugs that arise when a number of modules interact with each other

When Should Unit Testing Or Integration Testing Be Preferred?

Unit testing

It should be performed during the application development cycle. Ideally, the unit test should be written simultaneously while writing the code. Unit tests method before writing production code. If a unit test fails, testers know precisely which part of the code is not working correctly. This kind of feedback can help testers report the bugs to the Dev team, which fixes the bugs immediately instead of returning later to debug and find the bug in the code.

Integration Testing

It is usually performed during the earlier stage of the software development cycle. Selenium testing allows continuous testing of each daily build automatically. It is recommended that the integration tests are run when needed to ensure the units’ performance, reliability, and function.

Consequences Of Not Performing Unit And Integration Tests

Every strategic approach to ensuring seamless apps needs to embed the fundamental testing processes and should give allocate resources to facilitate bug-free execution. Every test approach has a crucial area to cover, and any negligence may pull down the overall quality of the application.

Without unit testing, it is likely that most of the bugs will remain undetected and will be revealed after the development stage. In such cases, QA engineers will look for the bugs and create tickets, after which the Dev team will fix those bugs and close the tickets. This leads to spending a lot of precious time and effort taken to fix bugs that could have been detected and fixed earlier to prevent code redeployment.

Likewise, integration testing is necessary to ensure that third-party applications and internal modules of an application perform well when the combination is tested together. In the absence of integration testing, the application will not undergo critical user-based scenarios and will fail to reveal the integration bottlenecks of the application.

Conclusion

The bottom line is that unit and integration tests successfully lead to developing a seamless software application without conducting both. However, when you compare unit testing vs integration testing both of them can reveal coding weaknesses that the other missed. It can also offer developers the necessary safety net needed to move forward with other automated tests that measure different levels of their application’s functionality and ensure that there are no back-end issues with the application’s infrastructure.

The post Unit Testing vs Integration Testing: An Informative Guide first appeared on TestingXperts.

Unit Testing – What is Its Importance in Software Testing?

sitemanager — Tue, 09 Jun 2020 15:44:37 +0000

Content 1. What is Unit Testing? 2. Why Unit Testing is important to perform? 3. What are the benefits of Unit Testing? 4. What are the types of Unit Testing? 5. Who performs Unit Testing? 6. How to do Unit Testing? 7. What are Unit Testing best practices? 8. What are some important Unit Test frameworks? 9. Unit Testing Vs Integration Testing 10. Conclusion

What is Unit Testing?

Unit testing is one of the software testing types which includes the initial testing phase where the smallest components or the modules of a software are tested individually. With this method of testing, both testers and developers can isolate each module, identify and fix the system defects at a very early stage of the software development lifecycle (SDLC). Primarily, a unit test verifies different behavioral aspects of the system under test and can be broadly classified into state-based and interaction-based unit testing.

A typical unit test consists of three phases which include the first initialization phase where it initializes a small piece of an application it wants to test. The second phase is the addition phase where it adds a stimulus to the system under test and finally, the third phase is the result phase where it observes the resulting application behavior. Evidently, if the observed behavior is consistent with expectations, then the unit test passes else it fails. This indicates there is a problem somewhere in the system under test. These three test phases are named as Arrange, Act and Assert or commonly known as AAA.

Why Unit Testing is important to perform?

Unit Testing is the software testing technique where a group of software program components or modules are tested individually. This technique effectively helps in validating the accuracy of a section of code by considering stubs, mock objects, drivers, and unit testing frameworks. Since it is practiced at the initial testing phase, this testing technique assures to identify and fix the bugs at the early stage of SDLC even before they become expensive for the enterprises to fix when identified at a later stage.

Some developers may attempt to save time by performing minimal unit testing, or when unit testing is skipped, it obviously leads to higher defect fixing costs during system testing, integration testing, and even beta testing when the application is completed.

Moreover, in addition to these, unit testing helps the development teams to understand the code base, validate the correctness of the developed code, reuse the code, and to make the changes faster in the code.

With a proper unit testing practice in place, the developers and testers can help to save time as bugs can be identified early in the process as it is the initial phase of testing. And, skipping or limiting the practice of unit testing can adversely increase the defects and it becomes complex to fix them at a later stage. Hence, it is essential to practice unit testing at the initial stage of the oftware testing process before planning for the integration testing.

What are the benefits of Unit Testing?

– Isolates a section of code and validates its correctness

– Helps in identifying and fixing the bugs at the early stage of the SDLC process

– Assures to reduce the cost as bugs are resolved at the earliest

– Helps the developers to improve the design by allowing refactoring of the code

– Assures in simplifying the debugging process

– With the proper unit testing practice, components that are integrated after the build can assure in achieving a quality product

What are the types of Unit Testing?

Basically, the unit testers make use of three types of unit testing while testing each module in the isolation that has been listed below.

White Box Testing

This testing practice is also known as transparent testing or glass box testing. In this unit testing type, the functional behavior of the software is tested by the developers in order to validate their execution.

Black-box Testing

In this unit testing type, the unit testers are not aware of the internal functionality of the system and are allowed for testing the structure of the function, i.e. the user interface, input, and output.

Gray Box Testing

Gray box testing is popularly known for being the combination of both black-box and white-box testing. In this method, the tester is partially aware of the system functionality and uses this approach for testing various test methods, for executing test suites, and to perform the risk assessment. Also, this unit testing type is known as semi-transparent testing.

Who performs Unit Testing?

Unit testing is the first software testing phase in SDLC and it is usually taken up during the development of the application. These unit test cases are written and executed by software developers. However, in certain exceptional scenarios where developers take a back off to this process, this white-box testing technique is performed by QA engineers.

How to do Unit Testing?

Unit testing can be performed in two methods, i.e. by manual testing and automated testing.

In order to practice unit testing with the manual testing method, it is essential for the unit testers to get a step-by-step instructional document. However, considering the efforts needed for manual testing, automated unit testing is often preferred by most enterprises.

The workflow of unit testing is performed in 4 stages:

1. Creating test cases

2. Reviewing test cases

3. Baselining test cases

4. Executing test cases

Unit Testing process involves:

– The developers write the code in the application for testing the function and would wait for the application to get deployed for removing the test code

– The code is then isolated by the developers to validate the dependencies between the code and other units. This way of isolating the code helps in identifying and eliminating the dependencies.

– Developers significantly make use of Unit test frameworks or unit testing tools for developing automated test cases.

– While executing the test cases, the unit test frameworks help to flag and report the failed test cases. Also, based on the failures in the test cases, the unit test frameworks help to stop the related testing.

What are Unit Testing best practices?

1. Ensure Unit Tests are independent of each other:

While performing unit testing, make sure that all the unit tests are independent. If having any dependencies, then unit tests can get affected when there are any changes or enhancements. Also, it can result in complexities for the test cases to run and debug. Hence, always make sure that unit test cases are independent.

2. Always stick to one code unit at once:

When testing a unit of code, though it relates to multiple use cases, unit testers have to test each use case in different test cases. This will effectively simplify the teams to do code changes or refactoring.

3. Make use of AAA for readability:

AAA stands for Arrange, Act, and Assert. This pattern helps in separating what is being tested from the “arrange” and “assert” steps; thus reduces the inter-mix of the assertions with the help of the “Act”. Thus, the test cases are more readable.

4. Fix the bugs before moving for Integration Testing:

Unit testing is the first testing phase and it is practiced before moving to the phase of integration testing. Hence, before moving for the next testing level, make sure to fix all the identified bugs in the unit testing phase.

5. Ensure to have proper variable naming:

In unit testing, one of the important and best practices is to have proper naming of the variables. Therefore, avoid using magic strings, and also follow clear and consistent naming conventions.

6. Always separate test code and production code:

While performing unit testing, make sure that the test code is not deployed with the source code in your build script.

What are some important Unit Test frameworks?

JUnit:

This is an open-source unit testing framework that works effectively for test-driven development. It is explicitly designed to support Java language. This tool is well-known for providing an easy approach for writing code.

NUnit:

This unit testing framework is completely written in C# and this belongs to the xUnit family. It is an open-source tool and is capable of supporting all .NET languages and serves the same purpose as JUnit.

TestNG:

This is an open-source test automation framework exclusively developed for Java programming language. This framework specifically resembles Junit & NUnit and supports concurrent testing along with support for annotation.

Jtest:

This is an IDE plugin with effective open-source frameworks. The effective feature that can be achieved with this plugin is one-click action for creating, scaling, and maintaining unit tests.

PHPUnit:

This testing tool is designed to support PHP language. The beneficial feature of this tool is that it uses pre-defined assertion methods to make the system behave in a specific manner.

HtmlUnit:

This is an open-source unit testing framework to support JavaScript. It offers many great features for the teams such as open-source Java library, support for protocols, proxy servers, cookies, etc.

Unit Testing Vs Integration Testing

Integration testing is the second software testing phase conducted after unit testing. In Integration testing, the small modules that are individually tested in the unit testing are integrated or combined to test the functionality of the modules when they are together. However, to understand these two testing phases more easily, their major differences have been listed below.

Unit Testing	Integration Testing
It is the initial testing phase in SDLC.	It is practiced after unit testing and before system testing.
In this testing practice, the smallest piece of the code is tested.	In this method, different modules are combined or integrated to test if they are working together.
Unit testing focuses on testing the functionality of the individual units	Integration testing focuses on identifying the bugs that are raised by integrating different modules.
Unit testing is a type of white-box testing.	Integration testing is a type of black-box testing.
It is performed by software developers or even by testers.	It is performed by testers.
Maintaining the unit test cases is cheaper.	Maintaining the integration test cases is expensive.
It is easy to find bugs in this method.	It is comparatively difficult for identifying issues in this method.
Unit testing is started with module specification.	Integration testing is started with interface specifications.

Conclusion:

Businesses can be ensured of bug-free and quality software if software testing is performed effectively from the initial stage of product development. Software testing has to be taken up from the very first stage, i.e. from the code level itself; and this can be achieved when software developers perform the unit testing.

Unit testing is the earliest testing practice that focuses on the code. With this testing approach, small modules of the program are tested individually. This approach benefits the teams in many ways such as early bug detection, fixing the code before they become expensive to resolve in the SDLC. Hence, practicing unit testing is essential for businesses to ensure that the developed software is bug-free and quality is assured from the initial stage of SDLC. Leverage unit testing services from independent QA testing services provider to make your software get high-quality. Talk to us

Related Queries on Unit Testing

Q1. What is the purpose of unit testing?

Ans. With a proper unit testing practice in place, the developers and testers can help to save time as bugs can be identified early in the process as it is the initial phase of testing.

Q2. When Should unit testing be performed?

Ans. It is essential to practice unit testing at the initial stage of the software testing process before planning for the integration testing.

Q3. Who performs Unit Testing?

Ans. These unit test cases are written and executed by software developers

Q4. What are unit testing frameworks?

Ans. Some important Unit Test frameworks are listed here.

The post Unit Testing – What is Its Importance in Software Testing? first appeared on TestingXperts.