Hello Everyone, I, a newbie, trying to learn about how jacoco works. I am trying to understand how jacoco gradle task actually facilitates jacoco's byte manipulation and instrumentation steps. I am trying to find the implementation of jacoco plugin to read more about it but unable to locate the entry point. Could you please point me to the right direction? Thanks in advance for your help!

Start here: https://github.com/gradle/gradle/blob/v8.10.2/platforms/jvm/jacoco/src/main/java/org/gradle/testing/jacoco/plugins/JacocoPlugin.java

Thankyou Thomas. I see that we often use jacocoTestReport task in our gradle config files. I am hoping somehow jacocoTestReport triggers the code in JacocoPlugin.java?

That task is registered by the plugin: https://github.com/gradle/gradle/blob/v8.10.2/platforms/jvm/jacoco/src/main/java/org/gradle/testing/jacoco/plugins/JacocoPlugin.java#L225

Thankyou so much. I have been doing string search with the name. No wonder I never found it.

As a rough sum-up, the jacoco plugin configures the test tasks so they use the JaCoCo agent. The JaCoCo agent is the one doing ad-hoc instrumentation to collect the values and write them to the exec files. The JaCoCo report task then calls JaCoCo and gives it those exec files and everything else it needs to generate the HTML report from it.

thankyou Björn for the detailed explanation.