Continuous testing in CI/CD in Testing Fundamentals - Build an Automation Script

Verify that the application builds and passes all tests automatically on each code commit

Preconditions (3)

Step 1: Commit and push a code change to the repository

Step 2: Open the CI/CD dashboard for the project

Step 3: Observe the pipeline start automatically

Step 4: Wait for the build and test stages to complete

Step 5: Check the test results in the pipeline report

✅ Expected Result: The pipeline triggers automatically on code commit, the build succeeds, all automated tests pass, and the test report shows no failures

Automation Requirements - Jenkins Pipeline with shell script and JUnit test reports

Assertions Needed:

Build stage completes successfully

Test stage completes successfully

Test report shows zero failed tests

Best Practices:

Use declarative pipeline syntax

Include explicit stages for build and test

Publish test results using JUnit plugin

Fail the pipeline if any test fails

Automated Solution

Testing Fundamentals

pipeline {
    agent any
    stages {
        stage('Build') {
            steps {
                echo 'Building the application...'
                sh 'mvn clean compile'
            }
        }
        stage('Test') {
            steps {
                echo 'Running automated tests...'
                sh 'mvn test'
            }
            post {
                always {
                    junit 'target/surefire-reports/*.xml'
                }
            }
        }
    }
    post {
        failure {
            echo 'Build or tests failed. Please check the logs.'
        }
        success {
            echo 'Build and tests passed successfully.'
        }
    }
}

This Jenkins pipeline script automates continuous testing in a CI/CD environment.

Agent any means the pipeline runs on any available agent.

There are two main stages: Build and Test.

In the Build stage, the command mvn clean compile compiles the application.

In the Test stage, mvn test runs automated tests.

The junit step publishes test results from the Surefire reports, so Jenkins can show test reports and fail the build if tests fail.

The post section handles messages on success or failure to inform the user.

This setup ensures that on every code commit, Jenkins builds the app, runs tests, and reports results automatically, which is the essence of continuous testing in CI/CD.

Common Mistakes - 3 Pitfalls

Not publishing test results with JUnit plugin

Using shell sleep commands to wait for build or tests

Not failing the pipeline on test failures

Bonus Challenge

Now add data-driven testing with 3 different input configurations in the test stage

Show Hint

Practice

1. What is the main purpose of continuous testing in a CI/CD pipeline?

easy

A. To automatically run tests on every code change

B. To manually test software after deployment

C. To delay testing until the final release

D. To only test code on the developer's machine

Solution

1. Step 1: Understand continuous testing concept

   Continuous testing means running tests automatically during the CI/CD process.

2. Step 2: Identify the purpose in CI/CD

   Its goal is to catch bugs early by testing every code change automatically.

3. Final Answer:

   To automatically run tests on every code change -> Option A

4. Quick Check:

   Continuous testing = automatic tests on code changes [OK]

Hint: Continuous testing means tests run automatically every change [OK]

Common Mistakes:

• Thinking testing is manual only
• Believing tests run after deployment
• Assuming testing happens only once at release

2. Which of the following is the correct syntax to run tests in a simple CI pipeline using a shell command?

easy

A. sh tests.sh

B. run tests.sh

C. execute tests.sh

D. start tests.sh

Solution

1. Step 1: Recall shell command syntax

   To run a shell script, the correct command is 'sh scriptname.sh'.

2. Step 2: Check each option

   sh tests.sh uses 'sh tests.sh' which correctly runs the script. Others are invalid shell commands.

3. Final Answer:

   sh tests.sh -> Option A

4. Quick Check:

   Shell script run = sh script.sh [OK]

Hint: Use 'sh script.sh' to run shell scripts in pipelines [OK]

Common Mistakes:

• Using 'run' or 'start' which are not shell commands
• Forgetting to use 'sh' before script name
• Confusing shell commands with other languages

3. Given this CI pipeline snippet:

steps:
  - name: Run tests
    run: |
      echo "Starting tests"
      pytest tests/
      echo "Tests done"

What will be the output if all tests pass?

medium

A. Starting tests\nTests failed

B. Starting tests\npytest: command not found

C. Starting tests\nTests done

D. Tests done\nStarting tests

Solution

1. Step 1: Analyze the commands in order

   The pipeline runs 'echo "Starting tests"', then 'pytest tests/', then 'echo "Tests done"'.

2. Step 2: Understand output if tests pass

   If pytest runs successfully, it outputs test results but here we focus on echo commands output. So output includes 'Starting tests' then 'Tests done'.

3. Final Answer:

   Starting tests\nTests done -> Option C

4. Quick Check:

   Echo commands print start and done messages [OK]

Hint: Echo commands print messages before and after tests [OK]

Common Mistakes:

• Assuming pytest output is shown instead of echo
• Mixing order of printed lines
• Thinking tests failed without error

4. In a CI pipeline, the test step fails with error: sh: pytest: command not found. What is the most likely cause?

medium

A. The test script has a syntax error

B. The pipeline skipped the test step

C. The tests directory is missing

D. pytest is not installed in the pipeline environment

Solution

1. Step 1: Interpret the error message

   The error 'sh: pytest: command not found' means the shell cannot find the pytest command.

2. Step 2: Identify cause in CI environment

   This usually means pytest is not installed or not in PATH in the pipeline environment.

3. Final Answer:

   pytest is not installed in the pipeline environment -> Option D

4. Quick Check:

   Command not found = missing installation [OK]

Hint: Command not found means tool missing or not installed [OK]

Common Mistakes:

• Assuming syntax error causes command not found
• Thinking missing tests directory causes this error
• Believing pipeline skipped the step without error

5. You want to add continuous testing to your CI/CD pipeline so tests run only if code changes affect the src/ directory. Which approach best achieves this?

hard

A. Run tests on every pipeline run regardless of changes

B. Configure the pipeline to run tests only when files in src/ change

C. Run tests only after deployment to production

D. Manually trigger tests after code review

Solution

1. Step 1: Understand conditional testing in CI/CD

   To save time, tests should run only when relevant code changes occur.

2. Step 2: Apply file path filters in pipeline configuration

   Configuring the pipeline to detect changes in src/ and run tests only then is the best approach.

3. Final Answer:

   Configure the pipeline to run tests only when files in src/ change -> Option B

4. Quick Check:

   Run tests conditionally based on changed files [OK]

Hint: Run tests only if relevant files change to save time [OK]

Common Mistakes:

• Running tests every time wastes resources
• Testing only after deployment delays bug detection
• Manual triggers reduce automation benefits