In XP, a task describes a piece of functionality that can be implemented by a developer pair in a few hours.
Test case
The specification of a test; it includes the target object, inputs, expected outputs, as well as context and side conditions of that test run.
Test driver
A program that runs a series of tests automatically.
Test first
Other terms are test-first programming, test-first design, or test-driven development. A software development approach that specifies the result of a manageably small implementation step in an automated test case before the actual coding takes place.
Test oracle
A function or algorithm that uses the input data to create the expected output data, so that a test can use it as expected output data.
Test suite
A set of test cases jointly run and viewed.
Also called execution context or lightweight process. A sequential control flow within a program with its own stack and program counter. Several threads can run in parallel within a program, that is, within the same address space.
An approach used, for example, for testing or design, where a hierarchical problem or system is initially viewed on the top hierarchical level to then be further decomposed. Opposite Bottom-up.
Unified Modeling Language. A visual modeling language for object-oriented software models standardized by the Object Management Group (OMG).
Unit test
A type of test that, in contrast to a system test, refers to a single unit (method, class, component) of a system rather than to the overall system.
Use case
The definition of a behavior of the software product based on gradually described interactions between user and system.
User story
Informal description of a functional requirement or product property in XP. A user story serves as the basis for acceptance tests that formally check whether the product complies with the described function or property.
Value semantics
An object should be viewed as a value when its identity is determined by its invariable state.
The simplest sequential software process model, where the analysis, design, coding, and testing phases are done sequentially for the entire system.
White-box test
An implementation-based test, in contrast to a specification-based test;

See also Black-box test.

Extended Markup Language. A family of technologies allowing one to define so-called markup languages (languages with a structure similar to HTML) and to create, exchange, and edit corresponding documents.
Extreme Programming. An agile development process, the origin of test-first development, among other things.