Clover is a code coverage tool that helps developers write better test code faster. It shows which parts of an application's code have been tested and which haven't. Using Clover, teams can prioritize their testing efforts and selectively test only the code that has changed. Clover helps tests run smarter by only running the necessary tests and ordering tests to fail fast, reducing build times from an average of 40 minutes to just 7 minutes. This provides developers with faster and clearer feedback on failures.

1. How to Test Smarter
and Fail Faster
An introduction to Clover
Brendan Humphreys

2. Clover shows
developers where
their code isn’t
tested

3. Code Coverage
What parts of an application were executed
during a test run, and which parts weren’t

4. Clover empowers
developers to write
better test code,
faster

9. Clover helps teams
prioritize their
testing effort

13. Clover helps teams
selectively test
their code

14. FAILING
FASTER

15. UNIT TESTING: GOOD

16. LOTS OF TESTS: GOOD

17. LONG RUNNING TIMES:
BAD

18. IDLE DEVELOPERS: BAD

19. NO LOCAL TESTING: BAD

20. OVERLOADED CI: BAD

21. SMARTER
TESTING

22. SMART #1:
ON RUN THE TESTS YOU
NEED

23. SMART #2:
ORDER TESTS TO FAIL
FAST

24. <junit ...>
<batchtest fork=quot;truequot; todir=quot;${test.results.dir}/resultsquot;>
<clover-optimized-testset snapshotfile=quot;${clv.snapshot}quot;>
<fileset dir=quot;src/testsquot; includes=quot;${test.includes}quot;
excludes=quot;${test.excludes}quot;/>
</clover-optimized-testset>
</batchtest>
</junit>

25. <profiles>
...
<profile>
<id>clover</id>
<build>
<plugins>
<plugin>
<groupId>com.atlassian.maven.plugins</groupId>
<artifactId>maven-clover2-plugin</artifactId>
<version>2.4.1</version>
<executions>
<execution>
<goals>
<goal>setup</goal>
<goal>optimize</goal>
<goal>snapshot</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
</profiles>

26. Normal Optimized
Avg = 40 minutes Avg = 7 minutes
Confluence CI Build

27. Faster Feedback
Normal Build
Anatoli waits 38 mins
for build failure
Clover Opt Build
Anatoli waits only
7 mins

28. Clearer Feedback
Normal Broken Build, three committers
Clover Opt Same broken Build, one committer

29. Test Smarter, Fail Faster
With Clover