Coverage reports in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to generate a coverage report using JaCoCo in a Maven project.

JUnit

<plugin>
  <groupId>org.jacoco</groupId>
  <artifactId>jacoco-maven-plugin</artifactId>
  <version>0.8.8</version>
  <executions>
    <execution>
      <goals>
        <goal>[1]</goal>
      </goals>
    </execution>
  </executions>
</plugin>

Drag options to blanks, or click blank then click option'

Apackage

Bcompile

Ctest

Dprepare-agent

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'test' instead of 'prepare-agent' causes no coverage data to be collected.

Using 'compile' or 'package' does not start the coverage agent.

The prepare-agent goal sets up the JaCoCo agent to collect coverage data during tests.

2fill in blank

medium

Complete the code to generate the coverage report after tests run.

JUnit

<execution>
  <id>report</id>
  <phase>[1]</phase>
  <goals>
    <goal>report</goal>
  </goals>
</execution>

Drag options to blanks, or click blank then click option'

Atest

Bcompile

Cverify

Dinstall

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'test' phase generates report too early before tests finish.

Using 'compile' phase is before tests run.

The verify phase runs after tests and is the right time to generate the coverage report.

3fill in blank

hard

Fix the error in the JaCoCo plugin configuration to correctly bind the report goal.

JUnit

<execution>
  <id>default-report</id>
  <phase>[1]</phase>
  <goals>
    <goal>report</goal>
  </goals>
</execution>

Drag options to blanks, or click blank then click option'

Averify

Bprepare-package

Ctest

Dcompile

Attempts:

3 left

💡 Hint

Common Mistakes

Binding to 'test' phase causes report generation before tests finish.

Binding to 'compile' phase is before tests run.

The verify phase is the correct lifecycle phase to bind the report goal for coverage reports.

4fill in blank

hard

Fill both blanks to create a JaCoCo report that includes XML and HTML formats.

JUnit

<configuration>
  <formats>
    <format>[1]</format>
    <format>[2]</format>
  </formats>
</configuration>

Drag options to blanks, or click blank then click option'

Axml

Bcsv

Chtml

Dtxt

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'csv' or 'txt' causes errors as they are unsupported formats.

Using only one format misses the other common report type.

JaCoCo supports xml and html formats for coverage reports.

5fill in blank

hard

Fill all three blanks to configure JaCoCo to fail the build if coverage is below 80%.

JUnit

<configuration>
  <rules>
    <rule>
      <element>[1]</element>
      <limits>
        <limit>
          <counter>[2]</counter>
          <value>[3]</value>
          <minimum>0.80</minimum>
        </limit>
      </limits>
    </rule>
  </rules>
</configuration>

Drag options to blanks, or click blank then click option'

ACLASS

BLINE

CINSTRUCTION

DCOVEREDRATIO

Attempts:

3 left

💡 Hint

Common Mistakes

Using unsupported elements or counters causes configuration errors.

Setting minimum above 1.0 or below 0 causes invalid rules.

The element is set to CLASS to check coverage per class, the counter is LINE to measure line coverage, and the value is COVEREDRATIO to specify the coverage ratio metric.

This configuration ensures the build fails if line coverage is below 80%.