Running a collection in Postman - Test Execution Trace

Test Overview

This test runs a Postman collection to verify that all API requests respond with status code 200, ensuring the APIs are reachable and working as expected.

Test Code - Newman (Postman CLI)

Postman

const newman = require('newman');

newman.run({
    collection: require('./MyCollection.json'),
    reporters: 'cli'
}, function (err, summary) {
    if (err) { throw err; }
    const failures = summary.run.failures;
    if (failures.length > 0) {
        console.error('Test failed: Some requests did not return status 200');
        process.exit(1);
    } else {
        console.log('All requests passed with status 200');
    }
});

Execution Trace - 6 Steps

Step	Action	System State	Assertion	Result
1	Test starts by invoking Newman to run the Postman collection file 'MyCollection.json'.	Newman CLI initializes and loads the collection with all API requests.	—	PASS
2	Newman sends the first API request defined in the collection.	Request sent to API endpoint; waiting for response.	—	PASS
3	Newman receives response and checks if status code is 200.	Response received with HTTP status code 200.	Verify response status code equals 200.	PASS
4	Newman repeats sending requests and checking status codes for all requests in the collection.	All requests executed sequentially with responses received.	Verify each response status code equals 200.	PASS
5	Newman completes running the collection and summarizes results.	Summary shows zero failures.	Check that no request failed the status code 200 check.	PASS
6	Test ends with console output confirming all requests passed.	Console displays 'All requests passed with status 200'.	—	PASS

Failure Scenario

Failing Condition: One or more API requests return a status code other than 200.

Execution Trace Quiz - 3 Questions

What does the test verify for each API request in the collection?

A That the response status code is 200

B That the response body contains JSON

C That the request URL is correct

D That the request method is POST

Key Result

Always verify the HTTP status code for each API request when running a collection to ensure the APIs are responding correctly.

Practice

1. What is the main purpose of Running a collection in Postman?

easy

A. To write code for APIs

B. To create new API endpoints

C. To execute a group of API requests in a specific order

D. To delete saved requests

Solution

1. Step 1: Understand what a collection is

   A collection in Postman is a group of API requests organized together.

2. Step 2: Purpose of running a collection

   Running a collection means executing all requests in that group one after another automatically.

3. Final Answer:

   To execute a group of API requests in a specific order -> Option C

4. Quick Check:

   Running a collection = executing grouped requests [OK]

Hint: Running a collection means running all requests together [OK]

Common Mistakes:

• Confusing running a collection with creating requests
• Thinking it deletes requests
• Assuming it writes code automatically

2. Which of the following is the correct way to start running a collection in Postman?

easy

A. Drag the collection to the trash bin

B. Right-click the collection and select 'Delete'

C. Open the collection and edit the request

D. Click the 'Run' button on the collection

Solution

1. Step 1: Locate the collection in Postman

   Collections appear in the sidebar with a 'Run' button visible when selected.

2. Step 2: Starting the run

   Clicking the 'Run' button starts executing all requests in the collection.

3. Final Answer:

   Click the 'Run' button on the collection -> Option D

4. Quick Check:

   Run button starts collection execution [OK]

Hint: Look for the 'Run' button to start collections [OK]

Common Mistakes:

• Choosing delete instead of run
• Editing requests does not run collection
• Dragging to trash deletes collection

3. Given a collection with 3 requests, if you run the collection and the second request fails, what happens next?

medium

A. The collection stops running immediately

B. The collection continues to run the third request

C. The collection retries the second request automatically

D. The collection deletes the failed request

Solution

1. Step 1: Understand default run behavior

   By default, Postman runs all requests in a collection sequentially regardless of individual request failures.

2. Step 2: Effect of a failed request

   A failed request does not stop the collection run; it moves on to the next request.

3. Final Answer:

   The collection continues to run the third request -> Option B

4. Quick Check:

   Collection runs all requests even if one fails [OK]

Hint: Collection runs all requests unless manually stopped [OK]

Common Mistakes:

• Assuming run stops on failure
• Thinking Postman retries automatically
• Believing failed requests get deleted

4. You try to run a collection but get an error saying 'No requests found'. What is the likely cause?

medium

A. The collection is empty with no requests inside

B. You have not selected any environment

C. Postman is offline

D. You clicked 'Run' on a single request instead of collection

Solution

1. Step 1: Analyze the error message

   'No requests found' means the collection has no requests to run.

2. Step 2: Check collection contents

   If the collection is empty, running it will cause this error.

3. Final Answer:

   The collection is empty with no requests inside -> Option A

4. Quick Check:

   Empty collection = no requests to run error [OK]

Hint: Check if collection has requests before running [OK]

Common Mistakes:

• Confusing environment selection with requests
• Assuming offline causes this error
• Thinking running single request triggers this

5. You want to run a collection multiple times with different data sets for each run. Which Postman feature helps you do this efficiently?

hard

A. Using a data file with the Collection Runner

B. Manually editing each request before running

C. Running each request separately

D. Duplicating the collection for each data set

Solution

1. Step 1: Identify the need for multiple data sets

   Running the same collection with different inputs requires data-driven testing.

2. Step 2: Use Collection Runner with data files

   Postman allows uploading CSV or JSON files to run collections multiple times with varied data.

3. Final Answer:

   Using a data file with the Collection Runner -> Option A

4. Quick Check:

   Data files + Collection Runner = multiple runs with different data [OK]

Hint: Use data files in Collection Runner for repeated tests [OK]

Common Mistakes:

• Editing requests manually wastes time
• Running requests separately is inefficient
• Duplicating collections is unnecessary