Editing Software testing (section)

==== Black-box testing ====
{{Main|Black-box testing}}
[[File:Black box diagram.svg|thumb|Black box diagram]]

Black-box testing (also known as functional testing) describes designing test cases without knowledge of the implementation, without reading the source code. The testers are only aware of what the software is supposed to do, not how it does it.<ref name="Patton">{{Cite book |last=Patton |first=Ron |url=https://archive.org/details/softwaretesting0000patt |title=Software Testing |publisher=Sams Publishing |year=2005 |isbn=978-0-672-32798-8 |edition=2nd |location=Indianapolis}}</ref> Black-box testing methods include: [[equivalence partitioning]], [[boundary value analysis]], [[all-pairs testing]], [[state transition table]]s, [[decision table]] testing, [[fuzz testing]], [[model-based testing]], [[use case]] testing, [[exploratory testing]], and specification-based testing.<ref name="LimayeSoftware09" /><ref name="SalehSoftware09" /><ref name="BlackPragmatic11" />

Specification-based testing aims to test the functionality of software according to the applicable requirements.<ref>{{Cite thesis |last=Laycock |first=Gilbert T. |title=The Theory and Practice of Specification Based Software Testing |degree=dissertation |publisher=Department of Computer Science, [[University of Sheffield]] |url=https://www.cs.le.ac.uk/people/glaycock/thesis.pdf |year=1993 |access-date=January 2, 2018}}</ref> This level of testing usually requires thorough [[test case]]s to be provided to the tester, who then can simply verify that for a given input, the output value (or behavior), either "is" or "is not" the same as the expected value specified in the test case. Test cases are built around specifications and requirements, i.e., what the application is supposed to do. It uses external descriptions of the software, including specifications, requirements, and designs, to derive test cases. These tests can be [[functional testing|functional]] or [[non-functional testing|non-functional]], though usually functional. Specification-based testing may be necessary to assure correct functionality, but it is insufficient to guard against complex or high-risk situations.<ref>{{Cite journal |last=Bach |first=James |author-link=James Bach |date=June 1999 |title=Risk and Requirements-Based Testing |url=https://www.satisfice.com/articles/requirements_based_testing.pdf |journal=Computer |volume=32 |issue=6 |pages=113–114 |access-date=August 19, 2008}}</ref>

Black box testing can be used to any level of testing although usually not at the unit level.<ref name="AmmannIntro16" />

'''Component interface testing'''

Component interface testing is a variation of [[black-box testing]], with the focus on the data values beyond just the related actions of a subsystem component.<ref name="MathurFound11-63">{{Cite book |last=Mathur, A.P. |url=https://books.google.com/books?id=hyaQobu44xUC&pg=PA18 |title=Foundations of Software Testing |publisher=Pearson Education India |year=2011 |isbn=978-81-317-5908-0 |page=63}}</ref> The practice of component interface testing can be used to check the handling of data passed between various units, or subsystem components, beyond full integration testing between those units.<ref name="Clapp">{{Cite book |last=Clapp |first=Judith A. |url=https://books.google.com/books?id=wAq0rnyiGMEC&pg=PA313 |title=Software Quality Control, Error Analysis, and Testing |year=1995 |isbn=978-0-8155-1363-6 |page=313 |publisher=William Andrew |access-date=January 5, 2018}}</ref><ref name="Mathur">{{Cite book |last=Mathur |first=Aditya P. |url=https://books.google.com/books?id=yU-rTcurys8C&pg=PR38 |title=Foundations of Software Testing |publisher=Pearson Education India |year=2007 |isbn=978-81-317-1660-1 |page=18}}</ref> The data being passed can be considered as "message packets" and the range or data types can be checked for data generated from one unit and tested for validity before being passed into another unit. One option for interface testing is to keep a separate log file of data items being passed, often with a timestamp logged to allow analysis of thousands of cases of data passed between units for days or weeks. Tests can include checking the handling of some extreme data values while other interface variables are passed as normal values.<ref name=Clapp/> Unusual data values in an interface can help explain unexpected performance in the next unit.

===== Visual testing =====

The aim of visual testing is to provide developers with the ability to examine what was happening at the point of software failure by presenting the data in such a way that the developer can easily find the information he or she requires, and the information is expressed clearly.<ref>{{Cite thesis |last=Lönnberg |first=Jan |title=Visual testing of software |date=October 7, 2003 |degree=MSc |publisher=Helsinki University of Technology |url=https://www.cs.hut.fi/~jlonnber/VisualTesting.pdf |access-date=January 13, 2012}}</ref><ref>{{Cite magazine |last=Chima |first=Raspal |title=Visual testing |url=http://www.testmagazine.co.uk/2011/04/visual-testing |magazine=TEST Magazine |archive-url=https://web.archive.org/web/20120724162657/http://www.testmagazine.co.uk/2011/04/visual-testing/ |archive-date=July 24, 2012 |access-date=January 13, 2012}}</ref>

At the core of visual testing is the idea that showing someone a problem (or a test failure), rather than just describing it, greatly increases clarity and understanding. Visual testing, therefore, requires the recording of the entire test process – capturing everything that occurs on the test system in video format. Output videos are supplemented by real-time tester input via picture-in-a-picture webcam and audio commentary from microphones.

Visual testing provides a number of advantages. The quality of communication is increased drastically because testers can show the problem (and the events leading up to it) to the developer as opposed to just describing it, and the need to replicate test failures will cease to exist in many cases. The developer will have all the evidence he or she requires of a test failure and can instead focus on the cause of the fault and how it should be fixed.

[[Ad hoc testing]] and [[exploratory testing]] are important methodologies for checking software integrity because they require less preparation time to implement, while the important bugs can be found quickly.<ref name="LewisSoftware16">{{Cite book |last=Lewis, W.E. |url=https://books.google.com/books?id=fgaBDd0TfT8C&pg=PA68 |title=Software Testing and Continuous Quality Improvement |publisher=CRC Press |year=2016 |isbn=978-1-4398-3436-7 |edition=3rd |pages=68–73}}</ref> In ad hoc testing, where testing takes place in an improvised impromptu way, the ability of the tester(s) to base testing off documented methods and then improvise variations of those tests can result in a more rigorous examination of defect fixes.<ref name="LewisSoftware16" /> However, unless strict documentation of the procedures is maintained, one of the limits of ad hoc testing is lack of repeatability.<ref name="LewisSoftware16" />

{{further|Graphical user interface testing}}