Testing pagination in Postman

Introduction

Testing pagination helps ensure that data is split correctly across pages. It checks that users can see all items without missing or repeating any.

When an API returns a large list of items split into pages.

When you want to verify the 'next' and 'previous' page links work correctly.

When checking that the number of items per page matches the expected limit.

When validating that the last page shows the remaining items correctly.

When ensuring no duplicate or missing items appear across pages.

Syntax

Postman

GET /items?page=1&limit=10

Use query parameters like page and limit to control pagination.

Check response fields for total items, current page, and links to next/previous pages.

Examples

Request the second page with 5 items per page.

Postman

GET /products?page=2&limit=5

Request the first page with 20 users per page.

Postman

GET /users?page=1&limit=20

Sample Program

This Postman test script checks that the pagination response has the correct current page, the number of items does not exceed the limit, total items is positive, and the next page link is present if there are more pages.

Postman

// Postman test script to check pagination

// Parse JSON response
const response = pm.response.json();

// Check current page is 1
pm.test('Current page is 1', () => {
    pm.expect(response.page).to.eql(1);
});

// Check number of items returned is less or equal to limit
pm.test('Items count is correct', () => {
    pm.expect(response.items.length).to.be.at.most(10);
});

// Check total items is a positive number
pm.test('Total items is positive', () => {
    pm.expect(response.total).to.be.above(0);
});

// Check next page link exists if more pages
pm.test('Next page link exists if not last page', () => {
    if (response.page * response.limit < response.total) {
        pm.expect(response.next).to.be.a('string').and.not.empty;
    } else {
        pm.expect(response.next).to.be.null;
    }
});

Important Notes

Always check both the data and the pagination metadata in the response.

Test edge cases like the first page, last page, and pages beyond the last.

Use Postman environment variables to automate testing multiple pages.

Summary

Pagination testing ensures users can navigate through data pages correctly.

Check page number, item count, total items, and navigation links.

Use Postman scripts to automate and validate pagination behavior.

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