Testing Types

        Installation testing

Main article: Installation testing

An installation test assures that the system is installed correctly and working at actual customer's hardware.

Compatibility testing

Main article: Compatibility testing

A common cause of software failure (real or perceived) is a lack of its compatibility with other application software, operating systems (or operating system versions, old or new), or target environments that differ greatly from the original (such as a terminal or GUI application intended to be run on the desktop now being required to become a web application, which must render in a web browser). For example, in the case of a lack of backward compatibility, this can occur because the programmers develop and test software only on the latest version of the target environment, which not all users may be running. This results in the unintended consequence that the latest work may not function on earlier versions of the target environment, or on older hardware that earlier versions of the target environment was capable of using. Sometimes such issues can be fixed by proactively abstracting operating system functionality into a separate program module or library.

Smoke and sanity testing

Sanity testing determines whether it is reasonable to proceed with further testing.

Smoke testing is used to determine whether there are serious problems with a piece of software, for example as a build verification test.

Regression testing

Main article: Regression testing

Regression testing focuses on finding defects after a major code change has occurred. Specifically, it seeks to uncover software regressions, or old bugs that have come back. Such regressions occur whenever software functionality that was previously working correctly stops working as intended. Typically, regressions occur as an unintended consequence of program changes, when the newly developed part of the software collides with the previously existing code. Common methods of regression testing include re-running previously run tests and checking whether previously fixed faults have re-emerged. The depth of testing depends on the phase in the release process and the risk of the added features. They can either be complete, for changes added late in the release or deemed to be risky, to very shallow, consisting of positive tests on each feature, if the changes are early in the release or deemed to be of low risk.

Acceptance testing

Main article: Acceptance testing

Acceptance testing can mean one of two things:

1.     A smoke test is used as an acceptance test prior to introducing a new build to the main testing process, i.e. before integration or regression.

2.     Acceptance testing performed by the customer, often in their lab environment on their own hardware, is known as user acceptance testing (UAT). Acceptance testing may be performed as part of the hand-off process between any two phases of development.^{[citation needed]}

Alpha testing

Alpha testing is simulated or actual operational testing by potential users/customers or an independent test team at the developers' site. Alpha testing is often employed for off-the-shelf software as a form of internal acceptance testing, before the software goes to beta testing.^[34]

Beta testing

Beta testing comes after alpha testing and can be considered a form of external user acceptance testing. Versions of the software, known as beta versions, are released to a limited audience outside of the programming team. The software is released to groups of people so that further testing can ensure the product has few faults or bugs. Sometimes, beta versions are made available to the open public to increase the feedback field to a maximal number of future users.^{[citation needed]}

Functional vs non-functional testing

Functional testing refers to activities that verify a specific action or function of the code. These are usually found in the code requirements documentation, although some development methodologies work from use cases or user stories. Functional tests tend to answer the question of "can the user do this" or "does this particular feature work."

Non-functional testing refers to aspects of the software that may not be related to a specific function or user action, such as scalability or other performance, behavior under certain constraints, or security. Testing will determine the flake point, the point at which extremes of scalability or performance leads to unstable execution. Non-functional requirements tend to be those that reflect the quality of the product, particularly in the context of the suitability perspective of its users.

Destructive testing

Main article: Destructive testing

Destructive testing attempts to cause the software or a sub-system to fail. It verifies that the software functions properly even when it receives invalid or unexpected inputs, thereby establishing the robustness of input validation and error-management routines.^{[citation needed]} Software fault injection, in the form of fuzzing, is an example of failure testing. Various commercial non-functional testing tools are linked from the software fault injection page; there are also numerous open-source and free software tools available that perform destructive testing.

Further information: Exception handling and Recovery testing

Software performance testing

Performance testing is generally executed to determine how a system or sub-system performs in terms of responsiveness and stability under a particular workload. It can also serve to investigate, measure, validate or verify other quality attributes of the system, such as scalability, reliability and resource usage.

Load testing is primarily concerned with testing that the system can continue to operate under a specific load, whether that be large quantities of data or a large number of users. This is generally referred to as software scalability. The related load testing activity of when performed as a non-functional activity is often referred to as endurance testing. Volume testing is a way to test software functions even when certain components (for example a file or database) increase radically in size. Stress testing is a way to test reliability under unexpected or rare workloads. Stability testing (often referred to as load or endurance testing) checks to see if the software can continuously function well in or above an acceptable period.

There is little agreement on what the specific goals of performance testing are. The terms load testing, performance testing, reliability testing, and volume testing, are often used interchangeably.

Further information: Scalability testing

Usability testing

Usability testing is needed to check if the user interface is easy to use and understand. It is concerned mainly with the use of the application.

Accessibility

Accessibility testing may include compliance with standards such as:

·        Americans with Disabilities Act of 1990

·        Section 508 Amendment to the Rehabilitation Act of 1973

·        Web Accessibility Initiative (WAI) of the World Wide Web Consortium (W3C)

Security testing

Security testing is essential for software that processes confidential data to prevent system intrusion by hackers.

Internationalization and localization

The general ability of software to be internationalized and localized can be automatically tested without actual translation, by using pseudolocalization. It will verify that the application still works, even after it has been translated into a new language or adapted for a new culture (such as different currencies or time zones).^[35]

Actual translation to human languages must be tested, too. Possible localization failures include:

·        Software is often localized by translating a list of strings out of context, and the translator may choose the wrong translation for an ambiguous source string.

·        Technical terminology may become inconsistent if the project is translated by several people without proper coordination or if the translator is imprudent.

·        Literal word-for-word translations may sound inappropriate, artificial or too technical in the target language.

·        Untranslated messages in the original language may be left hard coded in the source code.

·        Some messages may be created automatically at run time and the resulting string may be ungrammatical, functionally incorrect, misleading or confusing.

·        Software may use a keyboard shortcut which has no function on the source language's keyboard layout, but is used for typing characters in the layout of the target language.

·        Software may lack support for the character encoding of the target language.

·        Fonts and font sizes which are appropriate in the source language may be inappropriate in the target language; for example, CJK characters may become unreadable if the font is too small.

·        A string in the target language may be longer than the software can handle. This may make the string partly invisible to the user or cause the software to crash or malfunction.

·        Software may lack proper support for reading or writing bi-directional text.

·        Software may display images with text that was not localized.

·        Localized operating systems may have differently named system configuration files and environment variables and different formats for date and currency.

Development testing

Main article: Development Testing

Development Testing is a software development process that involves synchronized application of a broad spectrum of defect prevention and detection strategies in order to reduce software development risks, time, and costs. It is performed by the software developer or engineer during the construction phase of the software development lifecycle. Rather than replace traditional QA focuses, it augments it. Development Testing aims to eliminate construction errors before code is promoted to QA; this strategy is intended to increase the quality of the resulting software as well as the efficiency of the overall development and QA process.

Depending on the organization's expectations for software development, Development Testing might include static code analysis, data flow analysis metrics analysis, peer code reviews, unit testing, code coverage analysis, traceability, and other software verification practices.

The testing process