Testing Type Class Laws
Journal article, 2012

The specification of a class in Haskell often starts with stating, in comments, the laws that should be satisfied by methods defined in instances of the class, followed by the type of the methods of the class. This paper develops a framework that supports testing such class laws using QuickCheck. Our framework is a light-weight class law testing framework, which requires a limited amount of work per class law, and per datatype for which the class law is tested. We also show how to test class laws with partially-defined values. Using partially-defined values, we show that the standard lazy and strict implementations of the state monad do not satisfy the expected laws.

testing

verification

state monad

design

classes

languages

laws

Author

J. Jeuring

Utrecht University

Patrik Jansson

Chalmers, Computer Science and Engineering (Chalmers), Software Technology (Chalmers)

Claudio Amaral

Chalmers, Computer Science and Engineering (Chalmers), Software Technology (Chalmers)

SIGPLAN Notices (ACM Special Interest Group on Programming Languages)

0362-1340 (ISSN)

Vol. 47 12 49-60

Subject Categories

Software Engineering

DOI

10.1145/2430532.2364514