In this section, we will explore how to automate API tests using Newman, a command-line collection runner for Postman. Newman allows you to run and test Postman collections directly from the command line, making it an essential tool for integrating API tests into your continuous integration/continuous deployment (CI/CD) pipelines.

1. Newman Overview

   • Newman is a command-line tool that allows you to run Postman collections.
   • It is built on Node.js and can be installed via npm (Node Package Manager).
   • Newman supports all the features of Postman, including running collections, environments, and data files.

2. Installation

   • Ensure Node.js and npm are installed on your system.
   • Install Newman globally using npm:

     npm install -g newman
     

3. Running Collections with Newman

   • Basic command to run a collection:

     newman run <collection-file.json>
     

   • You can specify additional options such as environment files, data files, and more.

4. Options and Flags

   • -e or --environment: Specify an environment file.
   • -d or --iteration-data: Provide a data file for data-driven testing.
   • -r or --reporters: Choose reporters for output (e.g., CLI, JSON, HTML).

5. Integrating with CI/CD

   • Newman can be integrated into CI/CD pipelines to automate testing.
   • It can be used with popular CI/CD tools like Jenkins, Travis CI, and GitHub Actions.

Let's walk through a practical example of using Newman to run a Postman collection.

1. Open Postman and select the collection you want to export.
2. Click on the "..." (three dots) next to the collection name and select "Export".
3. Save the collection as a JSON file.

Assuming you have a collection file named MyCollection.json, you can run it using the following command:

If your collection requires an environment file and a data file, use the following command:

To generate an HTML report, use the -r flag:

This will create an HTML report in the current directory, providing a detailed view of the test results.

Task: Automate a Postman collection using Newman and generate an HTML report.

1. Export a Postman collection and an environment file.
2. Create a data file in CSV format if needed.
3. Run the collection using Newman with the environment and data files.
4. Generate an HTML report and review the results.

Solution:

1. Export the collection and environment file from Postman.
2. Create a CSV file named TestData.csv with the necessary data.
3. Run the following command:

   newman run MyCollection.json -e MyEnvironment.json -d TestData.csv -r html
   

4. Open the generated HTML report to review the test results.

• Ensure Correct File Paths: Double-check the paths to your collection, environment, and data files.
• Check Node.js and npm Installation: Make sure Node.js and npm are installed correctly before installing Newman.
• Use Descriptive Names: Name your files and collections descriptively to avoid confusion.

Automating tests with Newman is a powerful way to integrate API testing into your development workflow. By using Newman, you can ensure that your APIs are tested consistently and efficiently, reducing the risk of errors in production. In the next section, we will explore how to integrate Newman into a continuous integration pipeline, further enhancing your testing strategy.