PropErty Based TestingEnrique Paz @quiquepaz

Rolph de Ruiter

1/10

Goals of the day

• Underestanding DOs and DON’Ts of PBT• Formulating your own properties for pure functions• Designing and generating test data sets on the fly• And making you eager for more!

2/10

Goals of the day

• Underestanding DOs and DON’Ts of PBT• Formulating your own properties for pure functions• Designing and generating test data sets on the fly• And making you eager for more!

2/10

Goals of the day

• Underestanding DOs and DON’Ts of PBT• Formulating your own properties for pure functions• Designing and generating test data sets on the fly• And making you eager for more!

2/10

Goals of the day

• Underestanding DOs and DON’Ts of PBT• Formulating your own properties for pure functions• Designing and generating test data sets on the fly• And making you eager for more!

2/10

Property Based Testing Training Setup

• github.com/spilgames/PropEr@ErlangDCRB13I README.mdI Makefile + rebarI src/ with source and propertiesI test/*_eunit.erl as test controllers

3/10

Property Based Testing The Idea

• What properties should hold?• Properties document your code• Properties generate the testcases• Shrinking towards the smallest input that crashes

4/10

Property Based Testing The Idea

• What properties should hold?• Properties document your code• Properties generate the testcases• Shrinking towards the smallest input that crashes

4/10

Property Based Testing The Idea

• What properties should hold?• Properties document your code• Properties generate the testcases• Shrinking towards the smallest input that crashes

4/10

Property Based Testing The Idea

• What properties should hold?• Properties document your code• Properties generate the testcases• Shrinking towards the smallest input that crashes

4/10

Property Based Testing Available Tools

• Open Source• Plenty of documentation• Using & contributing via Github

• Available for multiple languages• Trainings and support (at a price)• Pulse for concurrency issues

5/10

Hands On! A Property

6/10

Conclusions The Stuff You’re Supposed To Remember

• Start with simple tests• Think properties• Always test your generators first• Test a reasonable success/error rate

7/10

Conclusions A Practical View

• Property Driven Development is not a thingI Thinking properties is hardI Refactoring properties is hardI Manual basic testcases help you think

• Naming is essential• Avoid reimplementating + comparing• PBT finds stuff you’d never think of

8/10

Conclusions A Practical View

• Property Driven Development is not a thingI Thinking properties is hardI Refactoring properties is hardI Manual basic testcases help you think

• Naming is essential• Avoid reimplementating + comparing• PBT finds stuff you’d never think of

8/10

Conclusions More Info

• PropEr @github• PropEr Docs• Quickcheck For Erlang• Concuerror @github• Concuerror Presentation

9/10

Conclusions Questions?

Leave us feedback! http://spkr8.com/t/28341

10/10