Analyze code quality with Sonar during Travis CI build

Sonar analysis is only run when the branch belongs to the pitest/pitclipse
repository. Indeed, sending the results of the the analysis to SonarCloud
requires the encrypted SONAR token which is not provided by Travis CI when
the build comes from a fork.

The code checking whether the analysis can be run is located in .travis/build.sh
and is called by the .travis.yml configuration file.

I also struggled a bit to encrypt the token because encryption on travis-ci.com
is different from encryption on travis-ci.org. For the record here is what I did:
 > travis login --pro
 > travis encrypt --pro <token> -r pitest/pitclipse

.travis.yml

@@ -6,25 +6,37 @@ jdk:
 # Prevent "mvn install" default step
 install: true
 
-env: DISPLAY=:99.0
-
 addons:
+  sonarcloud:
+    organization: "echebbi-github"
+    token:
+      secure: "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"
   apt:
     packages:
+      # Required by XVFB
       - metacity
 
+# Allow UI tests
+dist: trusty
+
 before_script:
-  - sh -e /etc/init.d/xvfb start
+  # Prepare the environment for UI tests
+  - "export DISPLAY=:99.0"
+  - "sh -e /etc/init.d/xvfb start"
+  - sleep 3 # give xvfb some time to start
   - metacity --sm-disable --replace 2> metacity.err &
   # Prevent installed packages from being used during build
   - rm -rfv "$HOME/.m2/repository/org/pitest/"
 
-script: mvn verify -P jacoco
+# build.sh is responsible of checking whether Sonar analysis can be run
+script: bash .travis/build.sh
+
 
 after_success:
   - bash <(curl -s https://codecov.io/bash)
 
 # Keep p2 information
 cache:
    directories:
-     - "$HOME/.m2/repository"
+     - "$HOME/.m2/repository"
+     - "$HOME/.sonar/cache"

.travis/build.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# IF the variable is set, we can run Sonar analysis.
+# Indeed, that means that the build is performed on a branch of the
+# pitest/pitclipse repository and that Travis CI allows us to use
+# encrypted variables (e.g. Sonar's token)
+if [ "${SONAR_SCANNER_HOME}" != "" ]; then
+    COMMAND="mvn verify -P jacoco sonar:sonar";
+
+# ELSE we cannot run Sonar analysis because the branch is coming
+# from a fork and Travis CI does not allow use to use encrypted variables.
+else
+    COMMAND="mvn verify -P jacoco";
+fi
+
+echo ${COMMAND}
+${COMMAND}

pom.xml

@@ -25,12 +25,27 @@
 		<!-- DEPENDENCIES -->
 		<tycho-version>1.4.0</tycho-version>
 		<jacoco-version>0.8.1</jacoco-version>
+
+		<!-- SONARQUBE -->
+		<sonar.projectName>Pitclipse</sonar.projectName>
+
+		<sonar.organization>echebbi-github</sonar.organization>
+		<sonar.links.ci>https://travis-ci.com/pitest/pitclipse</sonar.links.ci>
+		<sonar.links.scm>https://github.com/pitest/pitclipse</sonar.links.scm>
+		<sonar.links.issue>https://github.com/pitest/pitclipse/issues</sonar.links.issue>
+		<sonar.host.url>https://sonarcloud.io</sonar.host.url>
+		<sonar.java.source>8</sonar.java.source>
+		<!-- Ignore :
+				- Exceptions,
+				- untestable activators -->
+		<sonar.exclusions>**/*Exception.java,**/Activator.java</sonar.exclusions>
+		<sonar.jacoco.reportPaths>../../tests/${project.artifactId}.tests/target/jacoco.exec</sonar.jacoco.reportPaths>
 	</properties>
 
 	<!-- COMMANDS:
 	    * Build project:
 	    	mvn clean verify
-	    	
+
 		* Change project's version:
 			mvn org.eclipse.tycho:tycho-versions-plugin:set-version -DnewVersion=major.minor.bug
 	-->

releng/pom.xml

@@ -17,4 +17,8 @@
 		<module>org.pitest.pitclipse.target</module>
 		<module>org.pitest.pitclipse.p2</module>
 	</modules>
+
+	<properties>
+		<sonar.skip>true</sonar.skip>
+	</properties>
 </project>

sonar-project.properties

@@ -0,0 +1,23 @@
+sonar.projectName=Pitclipse
+sonar.projectKey=org.pitest:org.pitest.pitclipse
+
+# =====================================================
+#   Meta-data for the project
+# =====================================================
+
+sonar.links.ci=https://travis-ci.com/pitest/pitclipse
+sonar.links.scm=https://github.com/pitest/pitclipse
+sonar.links.issue=https://github.com/pitest/pitclipse/issues
+
+
+# =====================================================
+#   Properties that will be shared amongst all modules
+# =====================================================
+
+sonar.host.url=https://sonarcloud.io
+
+# =====================================================
+#   Java config
+# =====================================================
+
+sonar.java.source=8

tests/io.cucumber/pom.xml

@@ -0,0 +1,18 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<parent>
+		<groupId>org.pitest</groupId>
+		<artifactId>org.pitest.pitclipse.tests</artifactId>
+		<version>2.0.0-SNAPSHOT</version>
+	</parent>
+
+	<artifactId>io.cucumber</artifactId>
+	<packaging>eclipse-plugin</packaging>
+	<version>4.3.0</version>
+
+    <properties>
+        <sonar.skip>true</sonar.skip>
+    </properties>
+</project>