Erlang Code Evolution Control

TL;DR

This paper introduces an automated test suite generation method for Erlang code evolution, combining existing tools and user input to ensure behavior preservation across code versions.

Contribution

It presents a novel approach that integrates multiple tools and user-defined expressions to automatically generate targeted test cases for code evolution in Erlang.

Findings

Effective detection of behavioral differences between code versions

Automated test suite generation tailored to specific expressions

Open-source implementation available on GitHub

Abstract

During the software lifecycle, a program can evolve several times for different reasons such as the optimisation of a bottle-neck, the refactoring of an obscure function, etc. These code changes often involve several functions or modules, so it can be difficult to know whether the correct behaviour of the previous releases has been preserved in the new release. Most developers rely on a previously defined test suite to check this behaviour preservation. We propose here an alternative approach to automatically obtain a test suite that specifically focusses on comparing the old and new versions of the code. Our test case generation is directed by a sophisticated combination of several already existing tools such as TypEr, CutEr, and PropEr; and other ideas such as allowing the programmer to chose an expression of interest that must preserve the behaviour, or the recording of the sequences of values to which this expression is evaluated. All the presented work has been implemented in an open-source tool that is publicly available on GitHub.