Developers of Sonar core should :
- build with maven before commiting to subversion
- commit frequently into subversion
- never commit incomplete changes (Subversion is not a backup system)
- use meaningful comments when doing a subversion commit, always with the JIRA key and title (e.g. "SONAR-6 Apply license LGPL")
- subscribe to the mailing list firstname.lastname@example.org
- overuse unit tests (JUnit 4), with the help of hamcrest matchers and Mockito(mock objects)
- test on MySql AND Derby
- think IoC (Inversion of Control pattern)
- overuse functional tests (Selenium). Tests are written in the Selenese format (HTML).
- don't reinvent the wheel : use standard libraries like commons-lang, commons-io and google-collections (commons-collections is deprecated from Sonar 1.10)
- use comments and javadocs only when necessary
- do not forget the license header on all Java and Ruby files
- respect the code formatting described below
- eat your own food : analyze Sonar on Sonar.
- replace tabulations by 2 whitespaces
- right margin at 140 columns
- classes with acronyms are CamelCase : for example prefer PmdPlugin to PMDPlugin, or JavaNcssHandler to JavaNCSSHandler
- follow this template :
- replace : by :
Tips and tricks
Connect to Derby from command line
- download derby(the same version as used by sonar)
- set the DERBY_HOME property
- execute the command $DERBY_HOME/bin/ij
- connect to the database :
Compare XML files in JUnit
Use XMLUnit. The dependency is already defined into maven.
Warning : There's a bug on the similar() method. Contrary to the documentation, it fails if nodes are not in the same order.
Override Object.equals(), hashCode() and toString()
You can use EqualsBuilder and HashCodeBuilder from commons-lang to simplify. Just define the fields to compare. Example on the Rule class :
Debug the Maven plugin from IDE
- Two different ways :
1. Execute Maven debug command line : mvnDebug
2. Or edit $MAVEN_OPTS with :
Then execute Maven. It should block on :
- Attach your IDE to the remote process (the listening port is 8000).
Example on Intellij Idea : Run -> Edit configurations -> Add new configuration -> Remote -> port 8000.
Execute Selenium tests
- From firefox :
- Or from maven :
- cd tests/integration
- mvn install -P[browser] # with [browser] = firefox or ie or safari
Use JUnit4 advanced features
- assertThat() over assertTrue() : Stacktraces are more readable : instead of :
- use hamcrest extensions :