Understanding black-box and white-box testing

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Understanding black-box and white-box testing


3 min read

What is black-box testing?

Blackbox testing is a method of software testing that examines the functionality of an application without peering into its internal structures or workings. It is also known as functional testing or behavioral testing. The tester is only concerned with what the application does, not how it does it. The goal of black-box testing is to ensure that the application meets its requirements and behaves as expected for the end user.

Should we test internal parts with functional test cases?

Functional testing, also known as black-box testing, is focused on testing the software application's external behavior and functionality, as seen from the end user's perspective. It is not typically used to test the internal workings or structure of the application.

Internal parts of an application, such as individual modules or components, are typically tested using unit testing, which is a method of testing individual pieces of code in isolation. Developers typically write unit tests to verify that the code they have written is working correctly and meets the requirements.

That being said, it is possible to have functional test cases that test the internal parts of the application by testing the interaction of different internal components, in this case, it's called integration testing. This method of testing ensures that the various parts of the application are working together correctly and that there are no conflicts or issues when they are integrated.

In summary, functional testing is focused on the external behavior and functionality of the application, while unit testing and integration testing are focused on the internal parts of the application.

What are the key differences between black-box and white-box testing?

Black-box testers only have access to the inputs and outputs of the application, and not to the internal code. This method of testing is used to ensure that the application behaves as expected for the end user and meets its requirements.

On the other hand, white-box testers have access to the internal code and design of the application and use this information to test individual pieces of code to ensure that they are working correctly. This method of testing is used to ensure that the application is functioning correctly at the code level and to identify any bugs or issues that may not be visible from the user's perspective.

In summary, the key differences:

  • Black-box testing is done from the user's perspective, while white-box testing (unit, integration, etc.) is done from the developer's perspective.

  • Black-box testing does not require access to the internal code, while white-box testing requires access to the internal code.

  • Black-box testing is focused on testing the external functionality and behavior of the application, while white-box testing is focused on testing the internal code and design.