Types of Testing in software engineering скачать в хорошем качестве

Types of Testing in software engineering

Functional Testing Functional testing of a system involves tests that evaluate functions that the system should perform. Functional requirements may be described in work products such as business requirements specifications, epics, user stories, use cases, or functional specifications, or they may be undocumented. The functions are “what” the system should do. Functional tests should be performed at all test levels (e.g., tests for components may be based on a component specification), though the focus is different at each level Functional testing considers the behavior of the software, so black-box techniques may be used to derive test conditions and test cases for the functionality of the component or system The thoroughness of functional testing can be measured through functional coverage. Functional coverage is the extent to which some functionality has been exercised by tests, and is expressed as a percentage of the type(s) of element being covered. For example, using traceability between tests and functional requirements, the percentage of these requirements which are addressed by testing can be calculated, potentially identifying coverage gaps. Non-functional Testing Non-functional testing of a system evaluates characteristics of systems and software such as usability, performance efficiency or security. Refer to ISO standard (ISO/IEC 25010) for a classification of software product quality characteristics. Non-functional testing is the testing of “how well” the system behaves. Contrary to common misperceptions, non-functional testing can and often should be performed at all test levels, and done as early as possible. The late discovery of non-functional defects can be extremely dangerous to the success of a project. Black-box techniquesmay be used to derive test conditions and test cases for non- functional testing. For example, boundary value analysis can be used to define the stress conditions for performance tests. The thoroughness of non-functional testing can be measured through non-functional coverage. Non- functional coverage is the extent to which some type of non-functional element has been exercised by tests, and is expressed as a percentage of the type(s) of element being covered. For example, using traceability between tests and supported devices for a mobile application, the percentage of devices which are addressed by compatibility testing can be calculated, potentially identifying coverage gaps. Non-functional test design and execution may involve special skills or knowledge, such as knowledge of the inherent weaknesses of a design or technology (e.g., security vulnerabilities associated with particular programming languages) or the particular user base (e.g., the personas of users of healthcare facility management systems). It is possible to perform any of the test types mentioned above at any test level. To illustrate, examples of functional, non-functional, white-box, and change-related tests will be given across all test levels, for a banking application, starting with functional tests: • For component testing, tests are designed based on how a component should calculate compound interest. • For component integration testing, tests are designed based on how account information captured at the user interface is passed to the business logic. • For system testing, tests are designed based on how account holders can apply for a line of credit on their checking accounts. • For system integration testing, tests are designed based on how the system uses an external microservice to check an account holder’s credit score. • For acceptance testing, tests are designed based on how the banker handles approving or declining a credit application.