Resolving Missing JaCoCo Execution Data File | Generated by AI
To generate the JaCoCo execution data file, often referred to as a ‘.exec’ file, you need to run your tests with the JaCoCo agent attached. The log message “Skipping JaCoCo execution due to missing execution data file” indicates that the report goal was executed without the prepare-agent goal having been successfully run first.
Step 1: Configure the JaCoCo Maven Plugin
First, make sure your pom.xml file has the JaCoCo Maven plugin properly configured. It should look something like this:
<plugin>
<groupId>org.jacoco</groupId>
<artifactId>jacoco-maven-plugin</artifactId>
<version>0.8.12</version>
<executions>
<execution>
<goals>
<goal>prepare-agent</goal>
</goals>
</execution>
<execution>
<id>report</id>
<phase>test</phase>
<goals>
<goal>report</goal>
</goals>
</execution>
</executions>
</plugin>
The prepare-agent goal is crucial as it sets up the JaCoCo runtime agent. This agent instruments your code during the test run to collect coverage data.
Step 2: Run the Tests
After configuring the plugin, run your Maven build. The typical command to run tests and generate the report is:
mvn clean install
When you run this command, Maven executes the prepare-agent goal first, which attaches the JaCoCo agent to the JVM. Then, when the test phase runs, the agent records the code coverage data and saves it to a file, typically located at target/jacoco.exec. The report goal is then executed, which reads this .exec file and generates the final HTML or XML reports.
If you’re still facing issues, check the following:
- Project Structure: Ensure your tests are located in the standard Maven directory
src/test/java. - Test Failures: If your tests are failing, the build might stop before the
.execfile can be generated. Resolve any test failures first. - Version Mismatch: Make sure the JaCoCo plugin version is compatible with your Maven and Java versions.