Response time benchmarking in Postman - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Response Time Assertion in Postman Test Script

Given the following Postman test script snippet, what will be the result of the assertion if the response time is 350 ms?

Postman

pm.test('Response time is less than 300ms', function () {
    pm.expect(pm.response.responseTime).to.be.below(300);
});

A Test throws a syntax error due to incorrect function syntax

B Test is skipped because responseTime is undefined

C Test fails because 350 is greater than 300

D Test passes because 350 is less than 300

💡 Hint

Check the comparison operator and the actual response time value.

The assertion checks if the response time is below 300 ms. Since 350 ms is greater than 300 ms, the test fails.

🧠 Conceptual

intermediate

Understanding Response Time Metrics in Postman

Which Postman property correctly represents the total time taken for the server to send the full response?

A pm.response.responseTime

B pm.response.responseCode

C pm.response.responseSize

D pm.response.responseHeaders

💡 Hint

Look for the property that measures time duration.

pm.response.responseTime gives the total time in milliseconds taken to receive the full response from the server.

🔧 Debug

advanced

Debugging a Failing Response Time Test in Postman

A Postman test script intended to check if response time is under 500 ms is failing with a ReferenceError: pm is not defined. What is the most likely cause?

Postman

test('Response time under 500ms', function () {
    pm.expect(pm.response.responseTime).to.be.below(500);
});

A pm.response.responseTime is not a valid property in Postman

B Response time cannot be tested in Postman scripts

C The assertion syntax is incorrect; 'to.be.below' should be 'to.be.lessThan'

D The test script uses 'test' instead of 'pm.test', causing pm to be undefined

💡 Hint

Check the function used to define the test in Postman scripts.

In Postman scripts, tests must be defined using pm.test, not test. Using test causes pm to be undefined, leading to ReferenceError.

❓ framework

advanced

Best Practice for Benchmarking Response Time in Postman Collections

Which approach is best to benchmark average response time across multiple requests in a Postman collection?

A Use a collection-level pre-request script to start a timer and a test script to calculate and store each request's response time, then compute average after all requests

B Manually check each request's response time in the Postman console and calculate average externally

C Add a fixed delay in each request to simulate response time and compare delays

D Use pm.response.responseSize to estimate response time indirectly

💡 Hint

Think about automating timing and aggregation within Postman scripts.

Using collection-level scripts to track and store response times for each request allows automated calculation of average response time within Postman.

❓ assertion

expert

Complex Assertion for Response Time with Conditional Logging

In a Postman test script, which option correctly asserts that response time is below 400 ms and logs a warning if it is between 300 ms and 400 ms?

A

pm.test('Response time check', () => {
  const time = pm.response.responseTime;
  pm.expect(time).to.be.below(400);
  if (time > 300 && time <= 400) {
    console.warn('Warning: Response time is high but acceptable');
  }
});

B

pm.test('Response time check', () => {
  const time = pm.response.responseTime;
  pm.expect(time).to.be.below(400);
  if (time >= 300 && time < 400) {
    console.warn('Warning: Response time is high but acceptable');
  }
});

C

pm.test('Response time check', () => {
  const time = pm.response.responseTime;
  pm.expect(time).to.be.below(400);
  if (time > 300 && time < 400) {
    console.error('Warning: Response time is high but acceptable');
  }
});

D

pm.test('Response time check', () => {
  const time = pm.response.responseTime;
  pm.expect(time).to.be.below(300);
  if (time > 300 && time < 400) {
    console.warn('Warning: Response time is high but acceptable');
  }
});

💡 Hint

Check the assertion boundary and the logging method used for warnings.

Option B correctly asserts response time below 400 ms and logs a warning if time is between 300 (inclusive) and 400 (exclusive) ms using console.warn, which is appropriate for warnings.