Running a collection in Postman - Build an Automation Script

Run a Postman collection and verify all requests succeed

Preconditions (2)

Step 1: Open Postman application

Step 2: Select the 'User API Tests' collection from the left sidebar

Step 3: Click the 'Run' button to open the Collection Runner

Step 4: In the Collection Runner, ensure all requests are selected

Step 5: Click the 'Start Run' button to execute the collection

Step 6: Wait for all requests to complete

Step 7: Verify that each request shows a green checkmark indicating success

✅ Expected Result: All requests in the 'User API Tests' collection run successfully with status code 200 and show green checkmarks in the Collection Runner

Automation Requirements - newman

Assertions Needed:

Verify each request response status code is 200

Verify the collection run completes without errors

Best Practices:

Use explicit checks for response status codes

Handle asynchronous execution properly

Use descriptive test names for clarity

Automated Solution

Postman

import newman from 'newman';

newman.run({
  collection: require('./User_API_Tests.postman_collection.json'),
  reporters: 'cli'
}, function (err, summary) {
  if (err) {
    console.error('Collection run encountered an error:', err);
    process.exit(1);
  }

  const failures = summary.run.failures;
  if (failures.length > 0) {
    console.error(`Test failed: ${failures.length} request(s) did not pass.`);
    failures.forEach(failure => {
      console.error(`Request: ${failure.source.name}`);
      console.error(`Error: ${failure.error.test}`);
    });
    process.exit(1);
  } else {
    console.log('All requests passed successfully.');
  }
});

This script uses Newman, the command-line tool for running Postman collections.

We import Newman and call newman.run() with the collection file path.

The reporters: 'cli' option shows results in the console.

In the callback, we check for errors running the collection.

Then we check summary.run.failures array for any failed tests.

If there are failures, we print details and exit with error code.

If no failures, we print success message.

This ensures the automation verifies all requests passed with status 200 as defined in the collection tests.

Common Mistakes - 3 Pitfalls

Not handling asynchronous callback properly

Not checking the failures array in the summary

Hardcoding collection path without relative or absolute path

Bonus Challenge

Now add data-driven testing by running the collection with 3 different environment files

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