Lazy Systematic Unit TestingA J H Simons, JWalk: Lazy systematic unit testing of Java classes by design introspection and user interaction, ''Automated Software Engineering, 14 (4), December'', ed. B. Nuseibeh, (Boston: Springer, 2007), 369-418. is a software

unit test In computer programming, unit testing is a software testing method by which individual units of source code—sets of one or more computer program modules together with associated control data, usage procedures, and operating procedures&m ...

ing method based on the two notions of ''lazy specification'', the ability to infer the evolving specification of a unit on-the-fly by dynamic analysis, and ''systematic testing'', the ability to explore and test the unit's state space exhaustively to bounded depths. A testing toolkit

JWalk JWalk is a unit testing toolkit for the Java programming language.''The JWalk Home Page'', http://staffwww.dcs.shef.ac.uk/people/A.Simons/jwalk/ Created by Anthony Simons, JWalk supports a testing paradigm called Lazy Systematic Unit Testing.A J H ...

exists to support lazy systematic unit testing in the

Java programming language Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible. It is a general-purpose programming language intended to let programmers ''write once, run an ...

.''The JWalk Home Page'', http://www.dcs.shef.ac.uk/~ajhs/jwalk/

Lazy Specification

Lazy specification refers to a flexible approach to software specification, in which a specification evolves rapidly in parallel with frequently modified code. The specification is inferred by a semi-automatic analysis of a prototype software unit. This can include

static analysis Static analysis, static projection, or static scoring is a simplified analysis wherein the effect of an immediate change to a system is calculated without regard to the longer-term response of the system to that change. If the short-term effect i ...

(of the unit's interface) and dynamic analysis (of the unit's behaviour). The dynamic analysis is usually supplemented by limited interaction with the programmer. The term Lazy specification is coined by analogy with ''

lazy evaluation In programming language theory, lazy evaluation, or call-by-need, is an evaluation strategy which delays the evaluation of an expression until its value is needed ( non-strict evaluation) and which also avoids repeated evaluations ( sharing). T ...

'' in

functional programming In computer science, functional programming is a programming paradigm where programs are constructed by applying and composing functions. It is a declarative programming paradigm in which function definitions are trees of expressions that ...

. The latter describes the delayed evaluation of sub-expressions, which are only evaluated on demand. The analogy is with the late stabilization of the specification, which evolves in parallel with the changing code, until this is deemed stable.

Systematic Testing

Systematic testing refers to a complete,

conformance testing Conformance testing — an element of conformity assessment, and also known as compliance testing, or type testing — is testing or other activities that determine whether a process, product, or service complies with the requirements of a specif ...

approach to

software testing Software testing is the act of examining the artifacts and the behavior of the software under test by validation and verification. Software testing can also provide an objective, independent view of the software to allow the business to apprecia ...

, in which the tested unit is shown to conform exhaustively to a specification, up to the testing assumptions.A J H Simons, A theory of regression testing for behaviourally compatible object types, ''Software Testing, Verification and Reliability, 16 (3), UKTest 2005 Special Issue, September,'' eds. M Woodward, P McMinn, M Holcombe and R Hierons (Chichester: John Wiley, 2006), 133-156. This contrasts with exploratory, incomplete or random forms of testing. The aim is to provide repeatable guarantees of correctness after testing is finished. Examples of systematic testing methods include the

Stream X-Machine The Stream X-machine (SXM) is a model of computation introduced by Gilbert Laycock in his 1993 PhD thesis, ''The Theory and Practice of Specification Based Software Testing''.Gilbert Laycock (1993) ''The Theory and Practice of Specification Based ...

testing methodF Ipate and W M L Holcombe, Specification and testing using generalised machines: a presentation and a case study, ''Software Testing, Verification and Reliability, 8 (2),'' (Chichester: John Wiley, 1998), 61-81. and

equivalence partition Equivalence partitioning or equivalence class partitioning (ECP) is a software testing technique that divides the input data of a software unit into partitions of equivalent data from which test cases can be derived. In principle, test cases are ...

testing with full

boundary value analysis Boundary-value analysis is a software testing technique in which tests are designed to include representatives of boundary values in a range. The idea comes from the boundary. Given that we have a set of test vectors to test the system, a topology ...

References

{{reflist Unit testing