A functional test is a quality assurance process and a kind of black box testing that is performed to confirm that the functionality of an application or system is behaving as expected. Functions are tested by feeding them input and examining the output, and internal program structure is rarely considered. It mainly concentrates on the following aspects
Usage of testing techniques to check for error conditions. It checks whether suitable error messages are displayed.
Function Testing Techniques
The techniques used for functional testing are often specification-based. Testing functionality can be done from two perspective
Requirement-based testing: In this type of testing the requirements are prioritized depending on the risk criteria and accordingly the tests are prioritized. This will ensure that the most important and most critical tests are included in the testing effort
Business-process-based testing: In this type of testing the scenarios involved in the day-to-day business use of the system are described. It uses the knowledge of the business processes. For example, a personal and payroll system may have the business process along the lines of: someone joins the company, employee is paid on the regular basis and employee finally leaves the company.
Unit Testing is performed on the smallest elements of a system, such as individual classes within an application. Each component is tested to ensure that it properly handles input and output under normal operation, borderline use cases, and error conditions.
It is about testing a subset of test cases that cover the most important functionality of a component or system. It needs to be run quickly, often in the order of a few minutes and thus provides much quicker feedback and faster turnaround than the running of full test suites which can take hours or even days. Smoke tests broadly cover product features in a limited time. If key features don’t work or if key defects haven’t yet been fixed, your team won’t waste further time installing or testing.
Unlike smoke testing which is usually documented or scripted, provides coverage to the entire functionality of product from end to end and is like General Health Check Up; Sanity testing is usually not documented and is unscripted, it is done to verify the new functionality/defects have been fixed, it provides coverage to only the particular component of the entire system and is like specialized health check up.
It is about rerunning previously completed tests to verify whether program behavior has changed or whether previously fixed faults have re-emerged. It can be performed to test a system efficiently by systematically selecting the appropriate minimum set of tests needed to adequately cover a particular change.
It is about determining if the software is what the user would want to use and come back to or not. User expects web and mobile application to be efficient, effective, easy, simple, appealing, engaging etc. Usability testing makes sure that the interface is built in a way that fits the user’s expectations with respect to meeting requirements (effectiveness) easily (efficiently) in a simplistic satisfying manner.