Lazy systematic unit testing
Encyclopedia
Lazy Systematic Unit Testing is a software unit testing
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
exists to support lazy systematic unit testing in the Java programming language
.
, 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
(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 functional programming
. 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.
approach to software testing
, in which the tested unit is shown to conform exhaustively to a specification, up to the testing assumptions. 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
testing method and equivalence partition testing with full boundary value analysis
.
Unit test
In computer programming, unit testing is a method by which individual units of source code are tested to determine if they are fit for use.A unit is the smallest testable part of an application. In procedural programming a unit could be an entire module but is more commonly an individual function...
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
JWalk is a unit testing toolkit for the Java programming language. Created by , JWalk supports a testing paradigm called Lazy Systematic Unit Testing...
exists to support lazy systematic unit testing in the Java programming language
Java (programming language)
Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
.
Lazy Specification
Lazy specification refers to a flexible approach to software specificationFormal specification
In computer science, a formal specification is a mathematical description of software or hardware that may be used to develop an implementation. It describes what the system should do, not how the system should do it...
, 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 code analysis
Static program analysis is the analysis of computer software that is performed without actually executing programs built from that software In most cases the analysis is performed on some version of the source code and in the other cases some form of the object code...
(of the unit's interface) and dynamic analysis
Dynamic program analysis
Dynamic program analysis is the analysis of computer software that is performed by executing programs built from that software system on a real or virtual processor. For dynamic program analysis to be effective, the target program must be executed with sufficient test inputs to produce interesting...
(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
Lazy evaluation
In programming language theory, lazy evaluation or call-by-need is an evaluation strategy which delays the evaluation of an expression until the value of this is actually required and which also avoids repeated evaluations...
in functional programming
Functional programming
In computer science, functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions and avoids state and mutable data. It emphasizes the application of functions, in contrast to the imperative programming style, which emphasizes changes in state...
. 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 testingConformance testing
Conformance testing or type testing is testing to determine whether a product or system meets some specified standard that has been developed for efficiency or interoperability....
approach to software testing
Software testing
Software testing is an investigation conducted to provide stakeholders with information about the quality of the product or service under test. Software testing can also provide an objective, independent view of the software to allow the business to appreciate and understand the risks of software...
, in which the tested unit is shown to conform exhaustively to a specification, up to the testing assumptions. 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
Stream X-Machine
The Stream X-machine 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...
testing method and equivalence partition testing with full boundary value analysis
Boundary value analysis
Boundary value analysis is a software testing technique in which tests are designed to include representatives of boundary values. Values on the minimum and maximum edges of an equivalence partition are tested. The values could be either input or output ranges of a software component...
.