Automated Discovery of Faults and Fault Domains using Random Testing

Mian Asbat Ahmad

24-01-2013

Why random testing?

• Exhausting testing not possible.• Infinite values from 0 and 1.• Compatibility across multiple systems.• Limited Time and Resources

• Simple algorithm for data selection• Easy implementation• Free from human bias• Quick and effective in finding faults• Code Privacy

• Source code not required for Testing

Random Testing

• Black-box testing technique• Dynamic testing process• Input Domain• Random Selection

• Test Input• Test modules

• Test Execution• Test Evaluation

• Specifications• Language exceptions

• Test Output

Automated Random Testing

• Automating the process of random testing that include reading specifications, test data generation, test execution, result analysis and identification of the faulty tests.

• Examples of Automated Random testing tools are YETI, JCrasher, JUnit, Haskel etc…

• Fault lies in Domains [Chan et al]• Input Domain• Fault Domain

• Point Fault Domain• Block Fault Domain• Strip Fault Domain

Fault Domains

Enhancement in Random Testing

• Test Strategy?• Need of test strategy variations?

• High No of Faults• Less time• Low resources

• Famous Variations in Random Strategy• ART• MART• RRT• FD-ART• R+• QRT• …

Dirt Spot Sweeping Random Strategy

• Combination of strategies• Random

• Input and module selection at random• Random Plus

• Random testing with border values• Spot Sweeping

• Move around it when fault found

Working of DSSR

• Start with R and R+• Switch to DSSR,

when Fault found• After Evaluating

block/strip, switch back to R and R+

DSSR in Action

Evaluation of DSSR

• 60 classes selected from 32 different projects• In 43 classes all the strategies found same number of faults• In 17 classes strategies performed different than one another• DSSR found the highest number of faults• No strategy performed better than DSSR

Test Results of 17 classes

• DSSR performed better than R and R+• DSSR up to 33% better than R• DSSR up to 17% better than R+

DSSR Limitations

• Fault Domain• Existence Frequency

• Point, Block and Strip in programs• Domain Discovery

• Find Fault Domain of Program• Automated Method

• Domain Presentation

• Time to Find First Fault• DSSR uses R and R+ to start with• Use of Daikon to make it more targeted• Automated Method

Solutions to Limitations

• Automated Discovery of Failure Domain• Automated Method• Find Fault • Find its Domain• Plot Domain on Graph

• DSSR with Daikon/contracts• Execute class under test by Daikon• Get class invariants• Add data to R+ from invariants• Run DSSR • Reliance on simple R and R+ gone.

What is ADFD

• Automated Technique• Start Test• Find Fault• Generate a program Dynamically• Compile it• Execute it• Generate data• Generate Graphs

Working of ADFD using Example

• Program with multiple gaps• Or we can write program for• Point block or strip pattern• here

Generated Program for finding domain

Executed Program Output

Front End of ADFD

Daikon etc invariants border values…

• Automated Method• Run program by Daikon• Get invariants• Run DSSR with –ea