dr. florian deißenböck 26. januar 2017 - cqse · 2020. 5. 14. · * dme1737.c - driver for the...

Continuous Quality in Software Engineering

Software-Qualität

Dr. Florian Deißenböck26. Januar 2017

© CQSE GmbH 2017

Warum ist Software- Qualität wichtig?

Warum wird Software- Qualität immer wichtiger?

Welche Probleme gibt es?

Hilft das was?

Was kann man tun?

© CQSE GmbH 2017

Software-Wartung

Technologie: Hardware, BS, Sprachen, Datenbanken, …

Software-System

Anforderungen: Geschäftsprozesse, Fahrzeugfunktionen, …

© CQSE GmbH 2017




Hilft das was?

Was kann man tun?

© CQSE GmbH 2017

392 LOC

© CQSE GmbH 2017

Code von github.com/activiti

2728

29

© CQSE GmbH 2017

// Utilities for arrays of elementspublic String showElements(ModelElement[] elements,

String nomsg) {boolean found = false;StringBuffer res = new StringBuffer();if (elements != null) {Index.getInstance().setCurrentRenderer(FlatReferenceRenderer.getInstance());

for (int i = 0; i < elements.length(); i++) {ModelElement el = elements[i];res.append(showElementLink(el)).append(HTML.LINE_BREAK);

found = true;}Index.getInstance().setCurrentRenderer();if (!found && nomsg != null && nomsg.length() > 0) {res.append(HTML.italics(nomsg));

}return res.toString();

}




found = true;}Index.getInstance().setCurrentRenderer();if (!found && nomsg.length() > 0) {res.append(HTML.italics(nomsg));


}

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}






}

© CQSE GmbH 2017

Studie

Identifikation von über 100 Fehlern in produktiver Software

17

Kritisch Nutzersichtbar Nicht nutzersichtbar

44 46

Juergens et al., Do Code Clones Matter?, ICSE 2009

TODO: ist das wirklich Okay, einem QWidget einen QObject Parent zu geben?TODO: Soll das so sein? Jetzt echt? Alle alten Sachen in die Tonne?TODO: WEG MIT DIESEM DRECK - RK SOLLTE FÜR JEDEN INDEX IMMER…TODO: Nicht benutzen, hat hier überhaupt nix verlorenFIXME: solve timeout problemFIXME: REFACTOREN ! ich habe das jetzt einfache rüberkopiert, ist Müll soTODO: remove this hackTODO: Worin unterscheidet sich dieser Test vom vorherigen??

Code von github.com/activiti

Framework

Runner

Extensions

Core TextUI

Experimental

JUnit

HamcrestMatchers

Lib

Tests

Samples

/* * dme1737.c - Driver for the SMSC DME1737, Asus A8000, SMSC SCH311x, SCH5027, * and SCH5127 Super-I/O chips integrated hardware monitoring * features. * Copyright (c) 2007, 2008, 2009, 2010 Juerg Haefliger * * This driver is an I2C/ISA hybrid, meaning that it uses the I2C bus to access * the chip registers if a DME1737, A8000, or SCH5027 is found and the ISA bus * if a SCH311x or SCH5127 chip is found. Both types of chips have very * similar hardware monitoring capabilities but differ in the way they can be * accessed. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */

2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

© CQSE GmbH 2016




Hilft das was?

Was kann man tun?

© CQSE GmbH 2017

HTML/JSP

© CQSE GmbH 2017

Alle Logos sind von Wikipedia. Die Rechte daran hält die jeweilige Organisation.

Alle Logos sind von Wikipedia. Die Rechte daran hält die jeweilige Organisation.

2007 2008 2009 2010 2011 2012 2013 2014 2015

100k

150k

200kSLoC

1,200

1,400

1,600

1,800

Findings

Entwickler System

Pull

Dashboard

Entwickler System

Push

Dashboard

QualityEngineer

Task-Liste

Projektleiter Qualitätsbericht

QualityIndicator Full Assessment Delta Assessment

Stability ofRegular TeamBuilds

Build is stable.At the time of the last report,there was no automated build atall.

ArchitectureConformance

There are zero violations.Architecture specification wascompleted and is now fullyadhered to.

Stability of UnitTests

75 unit tests are passing butmany tests have been disabled.

Unit tests are now executedautomatically.

Code Coverage Cover coverage measurement is not yet enabled. is working on this.

CompilerWarnings

The code exhibits 7 compilerwarnings. However, it isquestionable if their removal isworthwhile.

The number of warnings wassignificantly reduced but not allfixes actually improve the codequality.

CodingGuidelinesViolations

The threshold of for typeswith any FxCop warning isviolated.

The amount of files with at leastone FxCop warning increased.

DuplicatedCode

With a clone coverage ofthe threshold ofi s slightlyviolated.

Clone coverage did not changesignificantly.

File SizeThe threshold regarding files >

LOC is violated.Use of partial classes improvesthe metric values but does notimprove code quality.

Nesting Depth Both thresholds are satisfied.All nestings deeper than havebeen removed.

Length ofLongestMethod

The threshold regardingmethods > LOC is violated.

The amount of types withmethods longer than LoCMdecreased significantly.

© CQSE GmbH 2017

2007 2008 2009 2010 2011 2012 2013 2014 2015

100k

150k

200kSLoC

1,200

1,400

1,600

1,800

Findings

© CQSE GmbH 2017

www.cqse.eu/en/blog

Dr. Florian Deißenbö[email protected]+49 179 7857188@deissenboeck

www.cqse.eu@cqse

www.teamscale.com@teamscaleTeamscale

© CQSE GmbH 2017

dr. florian deißenböck 26. januar 2017 - cqse · 2020. 5. 14. · * dme1737.c - driver for the...

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