Régression logicielle

A software regression is a type of software bug where a feature that has worked before stops working. This may happen after changes are applied to the software's source code, including the addition of new features and bug fixes. They may also be introduced by changes to the environment in which the software is running, such as system upgrades, system patching or a change to daylight saving time. A software performance regression is a situation where the software still functions correctly, but performs more slowly or uses more memory or resources than before. Various types of software regressions have been identified in practice, including the following: Local – a change introduces a new bug in the changed module or component. Remote – a change in one part of the software breaks functionality in another module or component. Unmasked – a change unmasks an already existing bug that had no effect before the change. Regressions are often caused by encompassed bug fixes included in software patches. One approach to avoiding this kind of problem is regression testing. A properly designed test plan aims at preventing this possibility before releasing any software. Automated testing and well-written test cases can reduce the likelihood of a regression. Techniques have been proposed that try to prevent regressions from being introduced into software at various stages of development, outlined below. Regression testing In order to avoid regressions being seen by the end-user after release, developers regularly run regression tests after changes are introduced to the software. These tests can include unit tests to catch local regressions as well as integration tests to catch remote regressions. Regression testing techniques often leverage existing test cases to minimize the effort involved in creating them. However, due to the volume of these existing tests, it is often necessary to select a representative subset, using techniques such as test-case prioritization.