Unit testing is now considered a mainstream practice, but that does not mean it is as common, pervasive or as well understood as it could or should be. Many programmers struggle with the quality of their tests and with the focus of their code. In this session we’ll learn how to write good unit testing code.
Unit testing patterns for concurrent codeDror Helper
Getting started with unit testing is not hard, the only problem is that most programs are more than a simple calculator with two parameters and a returns value that is easy to verify.
Writing unit tests for multi-threaded code is harder still.
Over the years I discovered useful patterns that helped me to test multi-threaded and asynchronous code and enabled the creation of deterministic, simple and robust unit tests.
Come learn how to test code that uses concurrency and parallelism – so that the excuses of not writing unit tests for such code would become as obsolete as a single core processors.
Unit testing is now considered a mainstream practice, but that does not mean it is as common, pervasive or as well understood as it could or should be. Many programmers struggle with the quality of their tests and with the focus of their code. In this session we’ll learn how to write good unit testing code.
Unit testing patterns for concurrent codeDror Helper
Getting started with unit testing is not hard, the only problem is that most programs are more than a simple calculator with two parameters and a returns value that is easy to verify.
Writing unit tests for multi-threaded code is harder still.
Over the years I discovered useful patterns that helped me to test multi-threaded and asynchronous code and enabled the creation of deterministic, simple and robust unit tests.
Come learn how to test code that uses concurrency and parallelism – so that the excuses of not writing unit tests for such code would become as obsolete as a single core processors.
Kill the mutants and test your tests - Roy van RijnNLJUG
Quis custodiet ipsos custodes? Better known as: *Who watches the watchmen?* We are all writing tests, doing TDD, BDD. We measure the quality of the tests with line coverage or (even better) branch coverage. This gives you a false sense of security. I've seen projects with tests which have 100% branch coverage but not a single assertion! This is where mutation testing helps out. By creating broken mutated instances of your codebase (mutants) this should result in failing unit tests. This way we can verify that slight code changes (like real life bugs) actually break your tests. In this talk I'll explain what mutation testing is and how it works. We'll also compare some Java frameworks (PIT, Jester, Jumble) that enable automatic mutation testing in your continuous build and how you can start doing mutation testing *right now*.
Sample Chapter of Practical Unit Testing with TestNG and MockitoTomek Kaczanowski
This is Chapter 10 of "Practical Unit Testing with TestNG and Mockito" book.
This is one of the last chapters which explains how to make your unit tests manageable, so they do not become a burden as the project develops and changes are introduced.
You can learn more about the book on http://practicalunittesting.com.
Hamcrest is a library for creating matchers for usage in unit tests, mocks and UI validation. This talk gives a brief introduction to using and writing Hamcrest matchers.
The topics covered:
* Basic introduction to Hamcrest
* Using Matchers in assertions
* Using Matchers with Mockito
* Writing custom matchers
* Ad-hoc matchers
PVS-Studio analyzer is continuously improving, and the C#-code analysis module is developing most actively: ninety new diagnostic rules were added in 2016. However, the best way to estimate the analyzer's efficiency is to look at the bugs it can catch. It's always interesting, as well as useful, to do recurring checks of large open-source projects at certain intervals and compare their results. Today I will talk about the results of the second analysis of SharpDevelop project.
A draft of the DI talk. I think that concepts are Ok but the format must be changed. In any case the content is the most important here and that it is ok.
Having a reliable test suite is incredibly useful when making changes to an existing codebase, both big and small. Mutation testing frameworks run tests against slightly-changed source code in order to detect whether the tests are actually checking the different paths of logic through the application. The aim is to improve the robustness of your test suite, and give you confidence that you aren't introducing any unintended changes.
This presentation gives an overview of mutation testing, along with worked examples in JavaScript of how it catches gaps and improves test coverage.
Date Processing Attracts Bugs or 77 Defects in Qt 6Andrey Karpov
The recent Qt 6 release compelled us to recheck the framework with PVS-Studio. In this article, we reviewed various interesting errors we found, for example, those related to processing dates. The errors we discovered prove that developers can greatly benefit from regularly checking their projects with tools like PVS-Studio.
Slides from my Confitura 2012 presentation. The issues discussed during the talk will be described in my new (free!) ebook - see https://github.com/tomekkaczanowski/bad-tests-good-tests
Every now and then, we have to write articles about how we've checked another fresh version of some compiler. That's not really much fun. However, as practice shows, if we stop doing that for a while, folks start doubting whether PVS-Studio is worth its title of a good catcher of bugs and vulnerabilities. What if the new compiler can do that too? Sure, compilers evolve, but so does PVS-Studio – and it proves, again and again, its ability to catch bugs even in high-quality projects such as compilers.
Kill the mutants and test your tests - Roy van RijnNLJUG
Quis custodiet ipsos custodes? Better known as: *Who watches the watchmen?* We are all writing tests, doing TDD, BDD. We measure the quality of the tests with line coverage or (even better) branch coverage. This gives you a false sense of security. I've seen projects with tests which have 100% branch coverage but not a single assertion! This is where mutation testing helps out. By creating broken mutated instances of your codebase (mutants) this should result in failing unit tests. This way we can verify that slight code changes (like real life bugs) actually break your tests. In this talk I'll explain what mutation testing is and how it works. We'll also compare some Java frameworks (PIT, Jester, Jumble) that enable automatic mutation testing in your continuous build and how you can start doing mutation testing *right now*.
Sample Chapter of Practical Unit Testing with TestNG and MockitoTomek Kaczanowski
This is Chapter 10 of "Practical Unit Testing with TestNG and Mockito" book.
This is one of the last chapters which explains how to make your unit tests manageable, so they do not become a burden as the project develops and changes are introduced.
You can learn more about the book on http://practicalunittesting.com.
Hamcrest is a library for creating matchers for usage in unit tests, mocks and UI validation. This talk gives a brief introduction to using and writing Hamcrest matchers.
The topics covered:
* Basic introduction to Hamcrest
* Using Matchers in assertions
* Using Matchers with Mockito
* Writing custom matchers
* Ad-hoc matchers
PVS-Studio analyzer is continuously improving, and the C#-code analysis module is developing most actively: ninety new diagnostic rules were added in 2016. However, the best way to estimate the analyzer's efficiency is to look at the bugs it can catch. It's always interesting, as well as useful, to do recurring checks of large open-source projects at certain intervals and compare their results. Today I will talk about the results of the second analysis of SharpDevelop project.
A draft of the DI talk. I think that concepts are Ok but the format must be changed. In any case the content is the most important here and that it is ok.
Having a reliable test suite is incredibly useful when making changes to an existing codebase, both big and small. Mutation testing frameworks run tests against slightly-changed source code in order to detect whether the tests are actually checking the different paths of logic through the application. The aim is to improve the robustness of your test suite, and give you confidence that you aren't introducing any unintended changes.
This presentation gives an overview of mutation testing, along with worked examples in JavaScript of how it catches gaps and improves test coverage.
Date Processing Attracts Bugs or 77 Defects in Qt 6Andrey Karpov
The recent Qt 6 release compelled us to recheck the framework with PVS-Studio. In this article, we reviewed various interesting errors we found, for example, those related to processing dates. The errors we discovered prove that developers can greatly benefit from regularly checking their projects with tools like PVS-Studio.
Slides from my Confitura 2012 presentation. The issues discussed during the talk will be described in my new (free!) ebook - see https://github.com/tomekkaczanowski/bad-tests-good-tests
Every now and then, we have to write articles about how we've checked another fresh version of some compiler. That's not really much fun. However, as practice shows, if we stop doing that for a while, folks start doubting whether PVS-Studio is worth its title of a good catcher of bugs and vulnerabilities. What if the new compiler can do that too? Sure, compilers evolve, but so does PVS-Studio – and it proves, again and again, its ability to catch bugs even in high-quality projects such as compilers.
La scrittura di test automatici nello sviluppo software è ormai di fondamentale importanza, in quanto permette di:
1. Individuare e correggere molto prima, già in fase di sviluppo, i bug.
2. Sviluppare e testare più velocemente il codice, riducendo di molto le volte in cui bisogna ricorrere al debugger.
3. Essere molto più confidenti che una modifica fatta ad un "vecchio" pezzo di codice non "rompa" tutto il resto e non funzioni più niente (ovviamente scoprendolo quando ormai si è rilasciato in produzione!).
Questi sono "solo" 3 di una quindicina di benefici che sono riuscito ad elencare, ottenibili utilizzando una pratica durante lo sviluppo del codice: la scrittura di test automatici.
Con questo workshop vogliamo introdurre gli sviluppatori ai test automatici, una pratica purtroppo non ancora conosciuta e utilizzata quanto meriterebbe, che può cambiare radicalmente il modo con cui scriviamo il codice, portandolo verso un approccio più "ingegneristico".
Faremo una panoramica sulle varie tipologie di test e sui benefici che possono portare, approfondendo in particolare i test unitari (unit test) e d'integrazione (integration test).
I test automatici sono un argomento trasversale ai linguaggi di programmazione, perciò potrete seguire il workshop a prescindere da quale linguaggio utilizziate.
Seconda serata di introduzione al Test-Driven Development, tenuta in XPeppers a Trento il 24 Ottobre 2012.
Nelle slide c'è anche la descrizione del coding dojo sullo string calculator che abbiamo svolto assieme.
This is a presentation I have given that provides an overview of TDD and why it is important. It's free for download an use, please attribute the work though. The original PPT has some animation that makes parts of it easier to understand. Thanks!
Chapter 10 Testing and Quality Assurance1Unders.docxketurahhazelhurst
Chapter 10:
Testing and Quality
Assurance
1
Understand quality & basic techniques for software verification and validation.
Analyze basics of software testing and testing techniques.
Discuss the concept of “inspection” process.
Objectives
2
Quality assurance (QA): activities designed
to measure and improve quality in a product— and process.
Quality control (QC): activities designed to validate and verify the quality of the product through detecting faults and “fixing” the defects.
Need good techniques, process, tools,
and team.
Testing Introduction
similar
3
Two traditional definitions:
Conforms to requirements.
Fit to use.
Verification: checking software conforms to
its requirements (did the software evolve
from the requirements properly; does the software “work”?)
Is the system correct?
Validation: checking software meets user requirements (fit to use)
Are we building the correct system?
What Is “Quality”?
4
Testing: executing program in a controlled environment and “verifying/validating” output.
Inspections and reviews.
Formal methods (proving software correct).
Static analysis detects “error-prone conditions.”
Some “Error-Detection” Techniques (finding errors)
5
Error: a mistake made by a programmer or software engineer that caused the fault, which in turn may cause a failure
Fault (defect, bug): condition that may cause a failure in the system
Failure (problem): inability of system to perform a function according to its spec due to some fault
Fault or failure/problem severity (based on consequences)
Fault or failure/problem priority (based on importance of developing a fix, which is in turn based
on severity)
Faults and Failures
6
Activity performed for:
Evaluating product quality
Improving products by identifying defects and having them fixed prior to software release
Dynamic (running-program) verification of program’s behavior on a finite set of test cases selected from execution domain.
Testing can NOT prove product works 100%—even though we use testing to demonstrate that parts of the software works.
Testing
Not always
done!
7
Who tests?
Programmers
Testers/Req. Analyst
Users
What is tested?
Unit code testing
Functional code testing
Integration/system testing
User interface testing
Testing (cont.)
Why test?
Acceptance (customer)
Conformance (std, laws, etc.)
Configuration (user vs. dev.)
Performance, stress, security, etc.
How (test cases designed)?
Intuition
Specification based (black box)
Code based (white box)
Existing cases (regression)
8
Progression of Testing
Equivalence Class Partitioning
Divide the input into several groups, deemed “equivalent” for purposes of finding errors.
Pick one “representative” for each class used for testing.
Equivalence classes determined by req./design specifications and some intuition
Example: pick “larger” of
two integers and . . .
Lessen duplication.
Complete coverage.
10
Suppose we have n distinct functional requirements.
Su ...
Accord.Net: Looking for a Bug that Could Help Machines Conquer HumankindPVS-Studio
Articles discussing the results of analysis of open-source projects are a good thing as they benefit everyone: some, including project authors themselves, can find out what bugs lurk in a project; others discover for themselves the static analysis technology and start using it to improve their code's quality. For us, it is a wonderful means to promote PVS-Studio analyzer, as well as to put it through some additional testing. This time I have analyzed Accord.Net framework and found lots of interesting issues in its code.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
zkStudyClub - Reef: Fast Succinct Non-Interactive Zero-Knowledge Regex ProofsAlex Pruden
This paper presents Reef, a system for generating publicly verifiable succinct non-interactive zero-knowledge proofs that a committed document matches or does not match a regular expression. We describe applications such as proving the strength of passwords, the provenance of email despite redactions, the validity of oblivious DNS queries, and the existence of mutations in DNA. Reef supports the Perl Compatible Regular Expression syntax, including wildcards, alternation, ranges, capture groups, Kleene star, negations, and lookarounds. Reef introduces a new type of automata, Skipping Alternating Finite Automata (SAFA), that skips irrelevant parts of a document when producing proofs without undermining soundness, and instantiates SAFA with a lookup argument. Our experimental evaluation confirms that Reef can generate proofs for documents with 32M characters; the proofs are small and cheap to verify (under a second).
Paper: https://eprint.iacr.org/2023/1886
In his public lecture, Christian Timmerer provides insights into the fascinating history of video streaming, starting from its humble beginnings before YouTube to the groundbreaking technologies that now dominate platforms like Netflix and ORF ON. Timmerer also presents provocative contributions of his own that have significantly influenced the industry. He concludes by looking at future challenges and invites the audience to join in a discussion.
PHP Frameworks: I want to break free (IPC Berlin 2024)Ralf Eggert
In this presentation, we examine the challenges and limitations of relying too heavily on PHP frameworks in web development. We discuss the history of PHP and its frameworks to understand how this dependence has evolved. The focus will be on providing concrete tips and strategies to reduce reliance on these frameworks, based on real-world examples and practical considerations. The goal is to equip developers with the skills and knowledge to create more flexible and future-proof web applications. We'll explore the importance of maintaining autonomy in a rapidly changing tech landscape and how to make informed decisions in PHP development.
This talk is aimed at encouraging a more independent approach to using PHP frameworks, moving towards a more flexible and future-proof approach to PHP development.
Enhancing Performance with Globus and the Science DMZGlobus
ESnet has led the way in helping national facilities—and many other institutions in the research community—configure Science DMZs and troubleshoot network issues to maximize data transfer performance. In this talk we will present a summary of approaches and tips for getting the most out of your network infrastructure using Globus Connect Server.
Why You Should Replace Windows 11 with Nitrux Linux 3.5.0 for enhanced perfor...SOFTTECHHUB
The choice of an operating system plays a pivotal role in shaping our computing experience. For decades, Microsoft's Windows has dominated the market, offering a familiar and widely adopted platform for personal and professional use. However, as technological advancements continue to push the boundaries of innovation, alternative operating systems have emerged, challenging the status quo and offering users a fresh perspective on computing.
One such alternative that has garnered significant attention and acclaim is Nitrux Linux 3.5.0, a sleek, powerful, and user-friendly Linux distribution that promises to redefine the way we interact with our devices. With its focus on performance, security, and customization, Nitrux Linux presents a compelling case for those seeking to break free from the constraints of proprietary software and embrace the freedom and flexibility of open-source computing.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
- How to streamline operations with automated policy checks on container images
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Pushing the limits of ePRTC: 100ns holdover for 100 daysAdtran
At WSTS 2024, Alon Stern explored the topic of parametric holdover and explained how recent research findings can be implemented in real-world PNT networks to achieve 100 nanoseconds of accuracy for up to 100 days.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
2. Testing is a good thing
But how do we know our tests are
good?
3. Code coverage is a start
But it can give a “good” score with
really dreadful tests
4. Really dreadful tests
class Adder
def self.add (x, y)
return x - y
end
end
describe Adder do
it "should add the two arguments" do
Adder.add(1, 1)
end
end
Coverage: 100%
Usefulness: 0
8. If you can change the code, and a
test doesn’t fail, either the code is
never run or the tests are wrong.
9. How?
1. Run test suite
2. Change code (mutate)
3. Run test suite again
If tests now fail, mutant dies. Otherwise it
survives.
10. Going with our previous example
class Adder
def self.add (x, y)
return x - y
end
end Let’s change something
describe Adder do
it "should add the two arguments" do
Adder.add(1, 1)
end
end
11. Going with our previous example
class Adder
def self.add (x, y)
return x + y
end
end
This still passes
describe Adder do
it "should add the two arguments" do
Adder.add(1, 1)
end
end
13. So what? It caught a really
rubbish test
How about something slightly less
obvious?
14. Slightly less obvious (and I mean slightly)
class ConditionChecker
def self.check(a, b)
if a && b
return 42
else
return 0
end
end
end
describe ConditionChecker do
it "should return 42 when both arguments are true" do
ConditionChecker.check(true, true).should == 42
end
it "should return 0 when both arguments are false" do
ConditionChecker.check(false, false).should == 0
end
end Coverage: 100%
Usefulness: >0
But still wrong
15. Slightly less obvious (and I mean slightly)
class ConditionChecker
def self.check(a, b)
if a && b
return 42
else Mutate
return 0
end
end
end
describe ConditionChecker do
it "should return 42 when both arguments are true" do
ConditionChecker.check(true, true).should == 42
end
it "should return 0 when both arguments are false" do
ConditionChecker.check(false, false).should == 0
end
end
16. Slightly less obvious (and I mean slightly)
class ConditionChecker
def self.check(a, b)
if a || b
return 42
else
return 0
end
end
end
describe ConditionChecker do Passing tests
it "should return 42 when both arguments are true" do
ConditionChecker.check(true, true).should == 42
end
it "should return 0 when both arguments are false" do
ConditionChecker.check(false, false).should == 0
end
end
19. The downfall of mutation
(Equivalent Mutants)
index = 0
while index != 100 do
doStuff()
index += 1
end
Mutates to
index = 0
while index < 100 do
doStuff()
index += 1
end
But the programs are equivalent, so no test will fail
20. There is no possible test which
can “kill” the mutant
The programs are equivalent
22. How bad is it?
• Good paper assessing the problem [SZ10]
• Took 7 widely used, “large” projects
• Found:
– 15 mins to assess one mutation
– 45% uncaught mutations are equivalent
– Better tested project -> worse signal-to-noise ratio
23. Can we detect the equivalents?
• Not in the general case [BA82]
• Some specific cases can be detected
– Using compiler optimisation techniques [BS79]
– Using mathematical constraints [DO91]
– Line coverage changes [SZ10]
• All heuristic algorithms – not seen any
claiming to kill all equivalent mutants
27. Ruby
• Mutant seems to be the new favourite
• Runs in Rubinius (1.8 or 1.9 mode)
• Only supports RSpec
• Easy to set up
rvm install rbx-head
rvm use rbx-head
gem install mutant
• And easy to use
mutate “ClassName#method_to_test” spec
28. Java
• Loads of tools to choose from
• Bytecode vs source mutation
• Will look at PIT (seems like one of the better
ones)
29. PIT - pitest.org
• Works with “everything”
– Command line
– Ant
– Maven
• Bytecode level mutations (faster)
• Very customisable
– Exclude classes/packages from mutation
– Choose which mutations you want
– Timeouts
• Makes pretty HTML reports (line/mutation coverage)
30. Summary
• Can point at weak areas in your tests
• At the same time, can be prohibitively noisy
• Try it and see
32. References
• [BA82] - T. A. Budd and D. Angluin. Two notions of correctness and
their relation to testing. Acta Informatica, 18(1):31-45, November
1982.
• [BS79] - D. Baldwin and F. Sayward. Heuristics for determining
equivalence of program mutations. Research report 276,
Department of Computer Science, Yale University, 1979.
• [DO91] - R. A. DeMillo and A. J. O
utt. Constraint-based automatic test data generation. IEEE
Transactions on Software Engineering, 17(9):900-910, September
1991.
• [SZ10] - D. Schuler and A. Zeller. (Un-)Covering Equivalent Mutants.
Third International Conference on Software Testing, Verification and
Validation (ICST), pages 45-54. April 2010.
33. Also interesting
• [AHH04] – K. Adamopoulos, M. Harman and R. M. Hierons. How to
Overcome the Equivalent Mutant Problem and Achieve Tailored
Selective Mutation Using Co-evolution. Genetic and Evolutionary
Computation -- GECCO 2004, pages 1338-1349. 2004.
Editor's Notes
Code changes include: arithmetic flip, boolean flip, access modifier change, statement deletion, and lots more
Difficult to identify equivalent mutants. There are some papers which suggest methods (but I didn’t have time to read them properly).
Paper called “(Un-)Covering Equivalent Mutants”7 projects: AspectJ, Barbecue, Apache Commons (Lang?), Jaxen, Joda-Time, JTopas, XStream
Undecidable problem for arbitrary pairs of programs [BA82]Constraints represent the conditions under which a mutant will die. If the constraint system cannot be true, there are no conditions under which it can die -> equivalent mutant.For arbitrary constraint systems, recognising feasibility is undecidable.Line coverage change supposedly a decent heuristic. Change means probably non-equivalent. 75% correctly classified.
Since most of the team do Ruby, I’ve had a look into that too
Looked into Heckle – since that was what the original topic of this talk was. Turns out it’s been dead for a long time.
Largely based on Heckle, rewritten on top of RubiniusOnly supports RSpec, but is that what’s used in the team? Author is looking to extend to other frameworks.Not sure if you need rubinius-head any more, but you did as of February 2012 (perhaps there’s a more stable version with support now)Also not sure about compatibility of Rubinius with the “official” Ruby implementation
Reason I mention Java: more mature ecosystem for these tools (interesting features which would be nice in Mutant)Bytecode is faster to mutate as it avoids recompilationsJumble and Jester also seem quite popular
Exclude logging/debug calls (3rd party logging frameworks excluded by default) -> Probably don’t care about asserts on these
If I’ve not hit the time limit, are there any questions?