lect-6-testing-intro

lect-6-testing-intro - 1 CSE503 SOFTWARE ENGINEERING...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 4/15/2011 1 CSE503: SOFTWARE ENGINEERING TESTING David Notkin Spring 2011 Andreas Zeller‟s talk 503 11sp © UW CSE • D. Notkin 2 Comments or questions? Today 503 11sp © UW CSE • D. Notkin 3 Some basics of software testing Characterizations of testing Terminology Basic approaches Mutation testing Random (feedback-directed) testing Next week: symbolic evaluation, concolic evaluation, automatic test generation and related topics – in some depth – many of the techniques used by Andreas (and others!) An example from Bach Asks students to “try long inputs” for a test requiring an integer Interesting lengths are…? 503 11sp © UW CSE • D. Notkin 4 Enter an integer: 4/15/2011 2 Key boundaries: most not tried 16 digits+: loss of mathematical precision 23+: can‟t see all of the input 310+: input not understood as a number 1000+: exponentially increasing freeze when navigating to the end of the field by pressing <END> 23,829+: all text in field turns white 2,400,000: reproducible crash Why more not tried? Seduced by what‟s visible Think they need the specification to tell them the maximum – and if they have one, stop there Satisfied by first boundary Use linear lengthening strategy Think “no one would do that” 503 11sp © UW CSE • D. Notkin 5 Free association: “software testing” 503 11sp © UW CSE • D. Notkin 6 Shout it out! Have any of you worked as a software tester? Many views of testing 503 11sp © UW CSE • D. Notkin 7 Showing you did something right vs. showing somebody else did something wrong Getting useful software into users‟ hands vs. stopping buggy software from getting into users‟ hands Finding defects vs. building confidence in properties Finding new bugs vs. making sure the rest of the team can make progress … Steve McConnell 503 11sp © UW CSE • D. Notkin 8 Testing by itself does not improve software quality. Test results are an indicator of quality, but in and of themselves, they don't improve it. Trying to improve software quality by increasing the amount of testing is like trying to lose weight by weighing yourself more often. What you eat before you step onto the scale determines how much you will weigh, and the software development techniques you use determine how many errors testing will find. If you want to lose weight, don't buy a new scale; change your diet. If you want to improve your software, don't test more; develop better. 4/15/2011 3 Cem Kaner & James Bach 9 “Testing is an empirical investigation conducted to provide stakeholders with information about the quality of the software under test.” “Testing is questioning a product in order to evaluate it....
View Full Document

This note was uploaded on 02/24/2012 for the course CSE 503 taught by Professor Davidnotikin during the Spring '11 term at University of Washington.

Page1 / 14

lect-6-testing-intro - 1 CSE503 SOFTWARE ENGINEERING...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online