Contracts in the Wild: A Study of Java Programs

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23520%2F17%3A43932733" target="_blank" >RIV/49777513:23520/17:43932733 - isvavai.cz</a>

Result on the web

—

DOI - Digital Object Identifier

—

Result language

angličtina

Original language name

Contracts in the Wild: A Study of Java Programs

Original language description

The use of formal contracts has long been advocated as an approach to develop programs that are provably correct. However, the reality is that adoption of contracts has been slow in practice. Despite this, the adoption of lightweight contracts — typically utilising runtime checking — has progressed. In the case of Java, built-in features of the language (e.g. assertions and exceptions) can be used for this. Furthermore, a number of libraries which facilitate contract checking have arisen. In this paper, we catalogue 25 techniques and tools for lightweight contract checking in Java, and present the results of an empirical study looking at a dataset extracted from the 200 most popular projects found on Maven Central, constituting roughly 351,034 KLOC. We examine (1) the extent to which contracts are used and (2) what kind of contracts are used. We then investigate how contracts are used to safeguard code, and study problems in the context of two types of substitutability that can be guarded by contracts: (3) unsafe evolution of APIs that may break client programs and (4) violations of Liskov’s Substitution Principle (LSP) when methods are overridden. We find that: (1) a wide range of techniques and constructs are used to represent contracts, and often the same program uses different techniques at the same time; (2) overall, contracts are used less than expected, with significant differences between programs; (3) projects that use contracts continue to do so, and expand the use of contracts as they grow and evolve; and, (4) there are cases where the use of contracts points to unsafe subtyping (violations of Liskov Substitution Principle) and unsafe evolution

Czech name

—

Czech description

—

Type

D - Article in proceedings

CEP classification

—

OECD FORD branch

10201 - Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8)

Project

<a href="/en/project/LO1506" target="_blank" >LO1506: Sustainability support of the centre NTIS - New Technologies for the Information Society</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

31st European Conference on Object-Oriented Programming

ISBN

978-3-95977-035-4

ISSN

—

e-ISSN

neuvedeno

Number of pages

29

Pages from-to

1-29

Publisher name

Schloss Dagstuhl

Place of publication

Schloss Dagstuhl

Event location

Barcelona, Spain

Event date

Jun 18, 2017

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

—