Slides from the presentation "Tests That Talk" delivered at Deovxx 2014. See Parleys.com for the full video https://www.parleys.com/speaker/5148920c0364bc17fc5697a5

1. TESTS THAT TALK
or
10 simple rules for cleaner, maintainable, readable tests

2. USEFUL RESOURCES
• Effective Unit Testing: A guide for Java developers - Lasse Koskela
• Clean Code & Clean Coder - Uncle Bob
• Test Driven Development - Kent Beck
• Specification By Example - Gojko Adzic
• Agile Testing: A Practical Guide for Testers and Agile Teams - Lisa
Crispin & Janet Gregory

3. DISTRIBUTE YOUR
EFFORTS
#1

4. Unit tests
Component tests
Integration tests
Performance tests
Acceptance Tests

5. #2
TEST CODE IS AS
IMPORTANT AS
PRODUCTION CODE

6. • It should be clean & maintainable
• it should be efficient and effective
• its behaviour should be deterministic
• don’t live with dead code
• this includes ignored tests!

7. • Given-When-Then / Given-Expect #win
• Name test methods like “shouldXXX”
• Use alphabetic suffixes rather than numerical as its
easier to read

8. TEST ONE THING AT
A TIME
#3

9. •Makes tracing failures easier
•Avoid loops, use parameterisation
• Promotes re-use of code
• Coupled with BDD-esque style means test reports
form detailed behavioural specifications

10. ENCAPSULATE DATA
OBJECT CREATION
#4

11. • Exploit builder patterns and internal DSLs for more
human-readable test setup
• Don’t mix test code with testing utility classes
•Test your utility classes (reuse!)

12. MOCKING
#5
INTRODUCES FRAGILITY

13. • An expectation on a mock object is an implicit
assumption that the concrete implementation
behaves in a specific way
• Has a tendency to introduce tight coupling
•Try to mock only across boundaries: view-controller
<-> service layer <-> persistence layer
• Minimise the amount of verification on mock
objects

14. DON’T REBUILD THE
WORLD IF ALL YOU
NEED IS TO REBUILD
THE HOUSE
#6

15. • Setting up test environments can be expensive
• When loading data, e.g. DbUnit, try and minimise
the dataset size
•Typically the higher up the “test pyramid” the more
expensive
• If a test “dirties” the environment prefer cleaning up
over recreating the environment
• Isolate tests to allow parallel execution on a shared
environment, e.g. user objects in integration tests

16. ASSERT IN ENGLISH*
*(IRONY NOTED)
#7

17. • JUnit’s assertThat + Hamcrest is a good start
•Writing custom matchers is easy
•Generics are a PITA
•Awaitility is a DSL for working with asynchronous
APIs
• JodaTime API is great for date/time comparisons
• Assertj is an extensible assertion framework more
natural than JUnit’s

18. CATEGORISE YOUR
TESTS
#8

19. •Group by:
•Speed
• Feature set
•Work in progress
•Layer
•OS/Browser
•Provide methods to execute a collection of test
groups as well as the full suite

20. #9 GO NATIVE

21. •Encourage non- & semi-technical participation in
feature specification with BDD frameworks
• JBehave
•CucumberJVM
•RAML
•lambda-behave
• Be the agent of change: Spock

22. HAVE FUN!
#10

23. IMAGES SOURCES
• http://free-extras.com/images/broken_heart-1503.htm
• http://www.makergear.com/products/m-series-3d-printers
• http://xkcd.com/435/
• http://justfree.org/fruit-clip-art

24. TESTS THAT TALK
or
10 simple rules for cleaner, maintainable, readable tests