Implementing Quality on Java projects (Short version)

Implementing Quality on Java projects (Short version)

• 2.
  Implementing Quality inJava
• 3.
  Vincent Massol ● SpeakerBio ● CTO XWiki SAS ● Your Projects ● XWiki (community-driven open source project) ● Past: Maven, Apache Cargo, Apache Cactus, Pattern Testing ● Other Credentials: ● LesCastCodeurs podcast ● Creator of OSSGTP open source group in Paris ● 3 books: JUnit in Action, Maven: A Developer’s Notebook, BBWM
• 4.
  What is quality?
• 5.
  The XWiki project
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  Examples of Qualityactions ● Coding rules (Checkstyle, ...) ● Test coverage ● Track bugs ● Don’t use Commons Lang 2.x ● Use SLF4J and don’t draw Log4J/JCL in dependencies ● Automated build ● Automated unit tests ● Stable automated functional tests ● Ensure API stability ● Code reviews ● License header checks ● Release with Java 6 ● Ensure javadoc exist ● Prevent JAR hell ● Release often (every 2 weeks) ● Collaborative design ● Test on supported environments (DB & Browsers)
• 7.
  Quality Tip #1 APIStability
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  Using CLIRR <plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>clirr-maven-pluginclirr-maven-plugin</artifactId> <configuration> <ignored> <difference> <differenceType>7006</differenceType> <className>org/xwiki/.../MetaDataBlock</className> <method>org.xwiki....block.Block clone()</method> <to>org.xwiki.rendering.block.MetaDataBlock</to> <justification>XDOM#clone()doesn't clone the meta data</justification> </difference> ...
• 9.
  CLIRR Report
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  Internal Package +AspectJ
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  Quality Tip #2 TestCoverage
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  Test Coverage Strategy ●When devs add code (and thus tests), increase the TPC percentage ● Put the Jacoco check in “Quality” Maven Profile ● Have a CI job to execute that profile regularly ● About 15% overhead compared to build without checks ● “Cheat mode”: Add easier-to-write test
• 13.
  Use Jacoco tofail the build <plugin> <groupId>org.jacoco</groupId> <artifactId>jacoco-maven-pluginjacoco-maven-plugin</artifactId> <executions> <execution><id>jacoco-prepare</id> <goals><goal>prepare-agentprepare-agent</goal></goals> </execution> <execution><id>jacoco-check</id> <goals><goal>checkcheck</goal></goals> </execution> </executions> <configuration> <check> <instructionRatio>${xwiki.jacoco.instructionRatio}${xwiki.jacoco.instructionRatio}</...> </check>}
• 14.
  Quality Tip #3 BugFixing Day
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  BFD Strategy ● EveryThursday ● Goal is to close the max number of bugs ● Triaging:Can be closed with Won’t fix, Duplicate, Cannot Reproduce, etc ● Close low hanging fruits in priority ● Started with last 365 days and currently with last 1500 days (we need to catch up with 80 bugs!)
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  Results
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  Conclusion ● Slowly addnew quality check over time ● Everyone must be on board ● Favor Active Quality (i.e. make the build fail) over Passive checks ● Be ready to adapt/remove checks if found not useful enough ● Quality brings some risks: ● Potentially less committers for your project (especially open source) ● Project seen as “less fun”
• 18.
  Be proud ofyour Quality ! “I have offended God and mankind because my work didn't reach the quality it should have.” Leonardo daVinci, on his death bed