In this exercise, you will learn how to integrate automated tests into your CI pipeline. Automated testing is a crucial part of CI/CD as it ensures that your code changes do not break existing functionality and helps maintain code quality.

• Understand the importance of automated testing in CI/CD.
• Learn how to set up automated tests in a CI pipeline.
• Execute and verify automated tests using a CI tool.

• Basic understanding of CI/CD concepts.
• Familiarity with a CI tool (e.g., Jenkins, GitLab CI/CD, CircleCI).
• A sample project with some existing tests (e.g., a simple Node.js application).

Ensure you have a CI environment set up. If you haven't done this yet, refer to the "Setting Up a CI Environment" section in Module 2.

Ensure your project has test scripts. For example, in a Node.js project, you might use a testing framework like Mocha or Jest.

Example: Adding Jest to a Node.js Project

1. Install Jest:

   npm install --save-dev jest
   

2. Add a test script to your package.json:

   {
     "scripts": {
       "test": "jest"
     }
   }
   

3. Create a simple test file, sum.test.js:

   const sum = require('./sum');
   
   test('adds 1 + 2 to equal 3', () => {
     expect(sum(1, 2)).toBe(3);
   });
   

4. Create the sum.js file:

   function sum(a, b) {
     return a + b;
   }
   module.exports = sum;
   

Configure your CI tool to run the tests as part of the pipeline.

Example: Configuring Jenkins

1. Create a new Jenkins job or pipeline.
2. In the pipeline configuration, add a stage to run tests.

Jenkins Pipeline Script Example:

Run the pipeline and verify that the tests are executed.

1. Trigger the pipeline manually or push a commit to the repository to trigger it automatically.
2. Monitor the pipeline execution in the CI tool's dashboard.
3. Check the test results in the pipeline logs.

Ensure that the tests pass successfully. If any tests fail, investigate the cause and fix the issues.

Common Issues and Solutions:

• Missing Dependencies: Ensure all required dependencies are installed.
• Incorrect Test Configuration: Verify that the test framework is correctly configured.
• Code Errors: Debug and fix any errors in the code or tests.

1. Set Up a Sample Project:

   • Create a simple Node.js project with a few test cases using Jest.

2. Configure Jenkins:

   • Set up a Jenkins pipeline to run the tests.

3. Run the Pipeline:

   • Execute the pipeline and verify that the tests run successfully.

Sample Node.js Project Structure:

package.json:

sum.js:

sum.test.js:

Jenkins Pipeline Script:

In this exercise, you learned how to integrate automated tests into a CI pipeline. Automated testing is essential for maintaining code quality and ensuring that new changes do not introduce bugs. By following the steps outlined, you can set up and run automated tests in your CI environment, helping you to catch issues early in the development process.

Next, you will learn about deploying your application in a production environment in the next exercise.