Code coverage reports in Jenkins - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to publish a code coverage report using the Jenkins pipeline.

Jenkins

publishCoverage adapters: [coberturaAdapter('**/[1]')], sourceFileResolver: sourceFiles('NEVER_STORE')

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

Acoverage.xml

Bresults.xml

Creport.xml

Doutput.xml

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong filename for the coverage report.

Forgetting to include the file extension.

The coberturaAdapter expects the coverage report file, commonly named coverage.xml.

2fill in blank

medium

Complete the Jenkins pipeline step to fail the build if coverage is below the threshold.

Jenkins

step([$class: 'CoveragePublisher', failUnhealthy: true, [1]: 80])

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

AcoverageThreshold

BcoverageMinimum

CcoverageLimit

DminimumCoverage

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect parameter names that cause the step to ignore the threshold.

Misspelling the parameter name.

The correct parameter to set the coverage threshold is coverageThreshold.

3fill in blank

hard

Fix the error in the Jenkins pipeline snippet to correctly archive the coverage report.

Jenkins

archiveArtifacts artifacts: '[1]', fingerprint: true

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

Acoverage-report.xml

Bcoverage.json

Creport.txt

Dcoverage.xml

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong file extension or filename.

Archiving a non-existent file.

The coverage report file to archive is coverage.xml, which Jenkins expects for coverage plugins.

4fill in blank

hard

Fill both blanks to configure the Jenkins pipeline to publish and fail on low coverage.

Jenkins

publishCoverage adapters: [[1]('**/coverage.xml')], failUnhealthy: [2]

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

AcoberturaAdapter

Btrue

Cfalse

DjacocoAdapter

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong adapter for the coverage report.

Setting failUnhealthy to false or missing it.

Use coberturaAdapter to read the coverage report and set failUnhealthy to true to fail the build if coverage is low.

5fill in blank

hard

Fill all three blanks to create a Jenkins pipeline snippet that collects coverage, archives the report, and sets a threshold.

Jenkins

publishCoverage adapters: [[1]('**/coverage.xml')]
archiveArtifacts artifacts: '[2]'
step([$class: 'CoveragePublisher', [3]: 75])

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

AcoberturaAdapter

Bcoverage.xml

CcoverageThreshold

DjacocoAdapter

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong adapter or filename.

Misspelling the threshold parameter.

This snippet uses coberturaAdapter to publish coverage, archives the coverage.xml file, and sets the coverageThreshold to 75%.

Practice

1. What is the main purpose of code coverage reports in Jenkins?

easy

A. To show which parts of the code are tested

B. To deploy the application automatically

C. To monitor server CPU usage

D. To manage user permissions

Solution

1. Step 1: Understand code coverage reports

   Code coverage reports indicate which parts of the source code have been executed during tests.

2. Step 2: Identify Jenkins role

   Jenkins uses these reports to help developers see test completeness and improve code quality.

3. Final Answer:

   To show which parts of the code are tested -> Option A

4. Quick Check:

   Code coverage = tested code parts [OK]

Hint: Coverage reports show tested code areas, not deployment [OK]

Common Mistakes:

• Confusing coverage with deployment
• Thinking coverage monitors server stats
• Mixing coverage with user management

2. Which Jenkins plugin is commonly used to publish Java code coverage reports?

easy

A. Git Plugin

B. JaCoCo Plugin

C. Docker Plugin

D. Slack Notification Plugin

Solution

1. Step 1: Identify coverage plugins for Java

   JaCoCo is a popular plugin for Java projects to generate code coverage reports in Jenkins.

2. Step 2: Exclude unrelated plugins

   Git manages source code, Docker manages containers, Slack sends messages, so they don't handle coverage.

3. Final Answer:

   JaCoCo Plugin -> Option B

4. Quick Check:

   Java coverage = JaCoCo [OK]

Hint: JaCoCo is the standard for Java coverage in Jenkins [OK]

Common Mistakes:

• Choosing Git for coverage
• Confusing Docker with coverage tools
• Selecting notification plugins

3. Given this Jenkins pipeline snippet, what will be the result of the jacoco step?

pipeline {
  agent any
  stages {
    stage('Test') {
      steps {
        junit '**/test-results.xml'
        jacoco execPattern: '**/jacoco.exec'
      }
    }
  }
}

medium

A. Publishes JaCoCo coverage report using the specified exec file

B. Runs unit tests and skips coverage report

C. Fails because jacoco is not a valid step

D. Publishes test results but ignores coverage data

Solution

1. Step 1: Understand the jacoco step usage

   The jacoco step in Jenkins pipeline publishes coverage reports using the exec file pattern provided.

2. Step 2: Analyze the snippet

   The pipeline runs tests with junit and then publishes coverage with jacoco execPattern: '**/jacoco.exec'.

3. Final Answer:

   Publishes JaCoCo coverage report using the specified exec file -> Option A

4. Quick Check:

   jacoco step publishes coverage report [OK]

Hint: jacoco step publishes coverage from exec files [OK]

Common Mistakes:

• Thinking jacoco runs tests
• Assuming jacoco step is invalid
• Ignoring coverage data in pipeline

4. You added the JaCoCo plugin to Jenkins but the coverage report does not appear after the build. What is the most likely cause?

medium

A. The Jenkins server is offline

B. The Jenkins user lacks admin rights

C. The build script does not run any tests

D. The jacoco.exec file path is incorrect or missing

Solution

1. Step 1: Check coverage report prerequisites

   JaCoCo needs the jacoco.exec file generated by tests to publish coverage.

2. Step 2: Identify common error

   If the exec file path is wrong or the file is missing, Jenkins cannot show the coverage report.

3. Final Answer:

   The jacoco.exec file path is incorrect or missing -> Option D

4. Quick Check:

   Missing exec file = no coverage report [OK]

Hint: Check jacoco.exec file path if coverage missing [OK]

Common Mistakes:

• Blaming Jenkins offline status
• Ignoring test execution for coverage
• Assuming user rights block coverage display

5. You want Jenkins to fail the build if code coverage falls below 80%. Which configuration should you add to the JaCoCo plugin in your pipeline?

hard

A. jacoco(execPattern: '**/jacoco.exec', failBuildIfCoverageLow: 80)

B. jacoco(execPattern: '**/jacoco.exec', changeBuildStatus: true, minimumCoverage: 80)

C. jacoco(execPattern: '**/jacoco.exec', changeBuildStatus: true, minimumInstructionCoverage: 80)

D. jacoco(execPattern: '**/jacoco.exec', coverageThreshold: 80)

Solution

1. Step 1: Understand JaCoCo coverage thresholds

   The JaCoCo plugin uses minimumInstructionCoverage to set the minimum coverage percentage for instructions.

2. Step 2: Identify correct syntax to fail build

   Setting changeBuildStatus: true with minimumInstructionCoverage: 80 makes Jenkins fail if coverage is below 80%.

3. Final Answer:

   jacoco(execPattern: '**/jacoco.exec', changeBuildStatus: true, minimumInstructionCoverage: 80) -> Option C

4. Quick Check:

   minimumInstructionCoverage + changeBuildStatus = fail below threshold [OK]

Hint: Use minimumInstructionCoverage with changeBuildStatus true [OK]

Common Mistakes:

• Using non-existent parameters like coverageThreshold
• Omitting changeBuildStatus to fail build
• Confusing minimumCoverage with minimumInstructionCoverage