This article discusses a set of tactics useful in software testing. It is intended as a comprehensive list of tactical approaches to software quality assurance (more widely colloquially known as quality assurance (traditionally called by the acronym "QA")) and general application of the test method (usually just called "testing" or sometimes "developer testing").
Installation testing
Installation testing evaluates whether a software system can be successfully installed in its intended environments (including operating systems, hardware, and specific system configurations). This tactic may also verify upgrade and uninstall procedures, as well as check for incorrect configurations and errors during setup.
The box approach Software testing methods are traditionally divided into white-box, black-box, and grey-box testing. These three approaches differ in the extent of visibility the test engineer has into the software product's internal algorithms and data structures when designing test cases.
White-box testing
White-box testing (also known as clear box testing, glass box testing, transparent box testing and structural testing, because the tester sees the source code) focuses on internal structures or workings of a program, as opposed to the functionality exposed to the end-user. In white-box testing, an internal perspective of the system, as well as programming skills, are used to design test cases. The tester chooses inputs to exercise paths through the code and determine the appropriate outputs. This is analogous to testing nodes in a circuit, e.g. in-circuit testing (ICT). Although white-box testing can be applied at the unit, integration and system levels of the software testing process, it is most frequently performed at the unit level. It can test paths within a unit, paths between units during integration, and between subsystems during a system-level test. Though this method of test design can uncover many errors or problems, it might not detect unimplemented parts of the specification or missing requirements. Techniques used in white-box testing include:
API testing – testing of the application using public and private APIs (application programming interfaces) Code coverage – creating tests to satisfy some criteria of code coverage (e.g., the test designer can create tests to cause all statements in the program to be executed at least once) Fault injection methods – intentionally introducing faults to gauge the efficacy of testing strategies Mutation testing methods Static testing methods Code coverage tools can evaluate the completeness of a test suite that was created with any method, including black-box testing. This allows the software team to examine parts of a system that are rarely tested and ensures that the most important function points have been tested. Code coverage as a software metric can be reported as a percentage for:
Function coverage, which reports on functions executed Statement coverage, which reports on the number of lines executed to complete the test Decision coverage, which reports on whether both the True and the False branch of a given test has been executed 100% statement coverage ensures that all code paths or branches (in terms of control flow) are executed at least once. This is helpful in ensuring correct functionality, but not sufficient since the same code may process different inputs correctly or incorrectly.
Black-box testing
Black-box testing treats the software as a "black box", examining functionality without any knowledge of internal implementation, without seeing the source code. The testers are only aware of what the software is supposed to do, not how it does it. Black-box testing methods include: equivalence partitioning, boundary value analysis, all-pairs testing, state transition tables, decision table testing, fuzz testing, model-based testing, use case testing, exploratory testing and specification-based testing. Specification-based testing aims to test software functionality according to the applicable requirements. This level of testing usually requires thorough test cases 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 or 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. One advantage of the black box technique is that no programming knowledge is required. Whatever biases the programmers may have had, the tester likely has a different set and may emphasize different areas of functionality. On the other hand, black-box testing has been said to be "like a walk in a dark labyrinth without a flashlight." Because they do not examine the source code, there are situations when a tester writes many test cases to check something that could have been tested by only one test case, or leaves some parts of the program untested. This testing method can be applied to all levels of software testing: unit, integration, system and acceptance. It typically comprises most if not all testing at higher levels, but can also dominate unit testing as well.
… excerpt ends here. Continue reading the full article.
