Introduction
Code coverage is the percentage of code coverage under any tests, ideally automated tests. Code coverage measurement simply determines which statements in a piece of code have been exercised through a set of test executions, and which statements have not. Here we are going to use Java Code Coverage or JaCoCo which is a free code coverage library for java.
One of things we are trying to do here on this example extra, is to combine coverage from multiple test executions, which is a very common case when coverge is gathered from multiple test-suites run on the same piece of code(SUT).
Steps to use Jacoco using java agent:
1. Set up the jacoco agent giving a specific port number for required service for which jacoco needs to be attached.
"-javaagent:<path-to-application>/src/main/resources/lib/jacocoagent.jar=address=*,port=<port-number>,destfile=jacoco-it.exec,output=tcpserver"
2. Start the services/execute code with the jacoco agent.
3. Run any tests which exercises the code.
4. Dump the results
Ex:- java -jar /Users/work/jacoco/lib/jacococli.jar dump --address localhost --port 36320 --destfile /Users/work/jacoco/reports/jacoco-it1.exec
java -jar /Users/work/jacoco/lib/jacococli.jar dump --address localhost --port 36330 --destfile /Users/work/jacoco/reports/jacoco-it2.exec
5. Collect instrumentation:
1. For a Single report:
java -jar /Users/work/jacoco/lib/jacococli.jar report /Users/work/mys/mysqlaas-integration-tests/tester/target/jacoco-it1.exec --classfiles /Users/work/mys/cp/api/target/classes/com --sourcefiles /Users/work/mys/cp/api/src/main/java/ --html /Users/work/mys/tests/target/jacoco-report
2. For Merging instrumentation of 2 or more reports:
Ex:- java -jar /Users/work/jacoco/lib/jacococli.jar merge /Users/work/jacoco/reports/jacoco-it1.exec /Users/work/jacoco/reports/jacoco-it2.exec --destfile /Users/work/jacoco/reports/jacoco-it.exec
3. Reports Generation types:
Using Classes: java -jar /Users/work/jacoco/lib/jacococli.jar report /Users/work/jacoco/reports/jacoco-it.exec --classfiles /Users/work/cp/api/target/classes/com --classfiles /Users/work/cp/worker/target/classes/com --sourcefiles /Users/work/cp/api/src/main/java/ --sourcefiles /Users/work/cp/worker/src/main/java/ --html /Users/work/jacoco/reports/jacoco-report
Using JAR’S:
java -jar /Users/work/jacoco/lib/jacococli.jar report /Users/work/jacoco/reports/jacoco-it.exec --classfiles /Users/work/cp/api/target/mysqlaas-api-0.0.1-SNAPSHOT.jar --classfiles /Users/work/cp/worker/target/mysqlaas-worker-0.0.1-SNAPSHOT.jar --sourcefiles /Users/work/cp/api/src/main/java/ --sourcefiles /Users/work/cp/worker/src/main/java/ --html /Users/work/jacoco/reports/jacoco-report
