Testing pagination in Postman - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is pagination in API testing?

Pagination is a technique to divide large sets of data into smaller chunks or pages, making it easier to retrieve and display data step-by-step.

beginner

Why do we test pagination in APIs?

We test pagination to ensure that the API correctly returns the right number of items per page, handles page navigation properly, and does not skip or repeat data.

intermediate

In Postman, how can you test the number of items returned per page?

You can write a test script using JavaScript in the Tests tab to check the length of the response array matches the expected page size.

beginner

What is a common parameter used for pagination in APIs?

Common parameters include 'page' (which page number to fetch) and 'limit' or 'pageSize' (how many items per page).

intermediate

How do you verify that pagination does not skip or repeat items?

By requesting multiple pages in sequence and checking that the combined data matches the full dataset without duplicates or missing items.

Which parameter typically controls the page number in API pagination?

A page

B limit

C sort

D filter

The 'page' parameter specifies which page of data to retrieve.

In Postman, where do you write scripts to test pagination responses?

A Tests tab

B Pre-request Script tab

C Body tab

D Headers tab

The Tests tab is used to write JavaScript code to validate responses.

What should you check to ensure pagination is working correctly?

A Response time only

B Only the first page data

C Number of items per page and correct page navigation

D Headers only

Testing pagination involves checking the number of items per page and that pages navigate correctly.

If an API returns 10 items per page, how many items should you get after requesting pages 1 and 2?

A 10

B 20

C 5

D Depends on the API

Two pages with 10 items each should return 20 items total.

Which test ensures no data is skipped or repeated across pages?

A Performance test

B UI test

C Security test

D Data integrity test

Data integrity tests verify that pagination returns all data without duplicates or missing items.

Explain how you would test pagination using Postman.

Think about parameters, requests, and validation scripts.

Why is testing pagination important in API testing?

Consider the impact on data retrieval and display.

Practice

1. What is the main purpose of testing pagination in an API using Postman?

easy

A. To verify that users can navigate through pages and see correct data counts

B. To check if the API returns data in alphabetical order

C. To ensure the API response time is under 1 second

D. To test if the API supports multiple languages

Solution

1. Step 1: Understand pagination purpose

   Pagination testing ensures users can move through pages and see correct data on each page.

2. Step 2: Identify key verification points

   We check page numbers, item counts, and total items to confirm correct navigation.

3. Final Answer:

   To verify that users can navigate through pages and see correct data counts -> Option A

4. Quick Check:

   Pagination = navigation + correct data [OK]

Hint: Pagination tests check page navigation and item counts [OK]

Common Mistakes:

• Confusing pagination with sorting
• Focusing only on response time
• Ignoring total item count

2. Which Postman script snippet correctly checks if the current page number is 3 in the response JSON?

easy

A. pm.test('Page is 3', () => pm.expect(pm.response.page).to.eql(3));

B. pm.test('Page is 3', () => pm.expect(response.page).to.equal(3));

C. pm.test('Page is 3', () => pm.expect(pm.response.json().page).to.eql(3));

D. pm.test('Page is 3', () => pm.expect(json.page).to.eql(3));

Solution

1. Step 1: Access response JSON correctly

   Use pm.response.json() to parse the response body as JSON.

2. Step 2: Use correct assertion syntax

   pm.expect(...).to.eql(3) checks if the page value equals 3.

3. Final Answer:

   pm.test('Page is 3', () => pm.expect(pm.response.json().page).to.eql(3)); -> Option C

4. Quick Check:

   Use pm.response.json() + pm.expect() [OK]

Hint: Use pm.response.json() to parse JSON before assertions [OK]

Common Mistakes:

• Using undefined variables like response or json
• Accessing pm.response.page directly
• Using to.equal instead of to.eql in Postman

3. Given this Postman test script, what will be the test result if the response JSON is {"page":2,"per_page":5,"total":12,"data":[1,2,3,4,5]}?

pm.test('Check page and items', () => {
  const json = pm.response.json();
  pm.expect(json.page).to.eql(2);
  pm.expect(json.data.length).to.eql(json.per_page);
  pm.expect(json.total).to.be.above(10);
});

medium

A. Test fails because page is not 2

B. Test fails because total is not above 10

C. Test fails because data length does not match per_page

D. All tests pass

Solution

1. Step 1: Check page number assertion

   json.page is 2, expected 2, so this passes.

2. Step 2: Check data length equals per_page

   json.data.length is 5, json.per_page is 5, so this passes.

3. Step 3: Check total is above 10

   json.total is 12, which is above 10, so this passes.

4. Final Answer:

   All tests pass -> Option D

5. Quick Check:

   All assertions true = pass [OK]

Hint: Match data length with per_page and check total > 10 [OK]

Common Mistakes:

• Assuming total must equal per_page
• Confusing page number with index
• Ignoring data array length

4. You wrote this Postman test to check pagination but it always fails:

pm.test('Page is 1', () => {
  const json = pm.response.json();
  pm.expect(json.page).to.equal(1);
});

The response JSON is {"page":1,"per_page":10,"total":50}. What is the likely error?

medium

A. The assertion syntax is correct; failure is due to response mismatch

B. Using to.equal instead of to.eql causes failure

C. pm.response.json() is not called correctly

D. The response JSON does not contain page key

Solution

1. Step 1: Check assertion method

   to.equal and to.eql behave similarly for primitives; this is not the cause.

2. Step 2: Verify response JSON keys

   Response has page key with value 1, so JSON access is correct.

3. Step 3: Consider response mismatch

   If test fails, likely the actual response page value differs or test runs on wrong response.

4. Final Answer:

   The assertion syntax is correct; failure is due to response mismatch -> Option A

5. Quick Check:

   Assertion syntax correct; check response data [OK]

Hint: Check actual response data if assertion syntax looks correct [OK]

Common Mistakes:

• Confusing to.equal and to.eql for primitives
• Assuming JSON parsing failed
• Ignoring actual response content

5. You want to test that the API correctly handles the last page of pagination when total items are 23 and per_page is 5. Which Postman test script correctly verifies the last page number and item count on that page?

hard

A. pm.test('Last page check', () => {
const json = pm.response.json();
pm.expect(json.page).to.eql(json.total);
pm.expect(json.data.length).to.eql(json.per_page);
});

B. pm.test('Last page check', () => {
const json = pm.response.json();
const lastPage = Math.ceil(json.total / json.per_page);
pm.expect(json.page).to.eql(lastPage);
pm.expect(json.data.length).to.eql(json.total % json.per_page || json.per_page);
});

C. pm.test('Last page check', () => {
const json = pm.response.json();
pm.expect(json.page).to.eql(json.total % json.per_page);
pm.expect(json.data.length).to.eql(json.per_page);
});

D. pm.test('Last page check', () => {
const json = pm.response.json();
pm.expect(json.page).to.eql(json.total / json.per_page);
pm.expect(json.data.length).to.eql(json.per_page);
});

Solution

1. Step 1: Calculate last page number

   Last page = ceiling of total / per_page = ceil(23/5) = 5.

2. Step 2: Calculate expected items on last page

   Items on last page = total % per_page = 23 % 5 = 3 (if 0, use per_page).

3. Step 3: Verify page number and data length

   Check json.page equals lastPage and json.data.length equals expected items.

4. Final Answer:

   pm.test('Last page check', () => { const json = pm.response.json(); const lastPage = Math.ceil(json.total / json.per_page); pm.expect(json.page).to.eql(lastPage); pm.expect(json.data.length).to.eql(json.total % json.per_page || json.per_page); }); -> Option B

5. Quick Check:

   Last page = ceil(total/per_page), items = remainder or per_page [OK]

Hint: Use Math.ceil for last page and remainder for last page items [OK]

Common Mistakes:

• Using division without ceiling for last page
• Expecting full per_page items on last page always
• Confusing modulo result with page number