Testing pagination in Postman - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the result of this Postman test script for pagination?

Consider a Postman test script that checks if the response contains exactly 10 items for page 1.

pm.test('Page 1 has 10 items', () => {
  const jsonData = pm.response.json();
  pm.expect(jsonData.items.length).to.eql(10);
});

What will be the test result if the response has 8 items?

Postman

pm.test('Page 1 has 10 items', () => {
  const jsonData = pm.response.json();
  pm.expect(jsonData.items.length).to.eql(10);
});

A Test fails with assertion error

B Test passes successfully

C Test throws a syntax error

D Test is skipped automatically

💡 Hint

Think about what happens when the expected number does not match the actual number.

The test expects exactly 10 items. If the response has 8 items, the assertion to.eql(10) fails, causing the test to fail with an assertion error.

🧠 Conceptual

intermediate

Which HTTP header is commonly used to control pagination in API requests?

When testing pagination in APIs, which HTTP header is typically used by clients to specify the page number or offset?

A Content-Type

B Range

C Accept

D Authorization

💡 Hint

Think about headers related to partial content or ranges.

The Range header is often used to specify which part of a resource to fetch, such as a range of items for pagination.

❓ assertion

advanced

Which Postman test assertion correctly verifies the presence of a 'next' page link in pagination?

You want to check if the JSON response contains a non-empty string field nextPageUrl indicating the next page link.

A pm.expect(pm.response.json().nextPageUrl).to.be.true;

B pm.expect(pm.response.json().nextPageUrl).to.exist.and.not.empty();

C pm.expect(pm.response.json().nextPageUrl).to.be.a('string').and.not.empty;

D pm.expect(pm.response.json().nextPageUrl).to.have.length.above(0);

💡 Hint

Check the correct syntax for asserting a non-empty string in Postman.

Option C correctly asserts that nextPageUrl is a string and is not empty. Option C uses invalid chaining, C assumes it's an array or string but lacks type check, D expects a boolean which is incorrect.

🔧 Debug

advanced

Why does this Postman pagination test script fail with a TypeError?

Given this test script:

pm.test('Check page items count', () => {
  const items = pm.response.json().data.items;
  pm.expect(items.length).to.eql(10);
});

The test fails with TypeError: Cannot read property 'items' of undefined. What is the most likely cause?

Postman

pm.test('Check page items count', () => {
  const items = pm.response.json().data.items;
  pm.expect(items.length).to.eql(10);
});

A The response JSON does not have a 'data' field

B The 'items' field is null instead of an array

C The 'items' field is an empty array

D The pm.expect syntax is incorrect

💡 Hint

Check the path used to access the items array in the JSON response.

If the 'data' field does not exist, accessing data.items returns undefined, so items is undefined and accessing items.length causes a TypeError.

❓ framework

expert

Which Postman test script snippet correctly tests that all pages of a paginated API return exactly 10 items?

You want to write a Postman test that loops through pages 1 to 3 and asserts each page returns 10 items in the 'items' array.

A

for(let page=1; page<=3; page++) {
  pm.sendRequest({url: `https://api.example.com/data?page=${page}`}, (err, res) => {
    pm.expect(res.json().items).to.have.lengthOf(10);
  });
}

B

for(let page=1; page<=3; page++) {
  pm.sendRequest({url: `https://api.example.com/data?page=${page}`}, (err, res) => {
    pm.expect(res.json().items.length).to.eql(10);
  });
}

C

for(let page=1; page<=3; page++) {
  pm.test(`Page ${page} has 10 items`, () => {
    pm.sendRequest({url: `https://api.example.com/data?page=${page}`}, (err, res) => {
      pm.expect(res.json().items.length).to.eql(10);
    });
  });
}

D

for(let page=1; page<=3; page++) {
  pm.sendRequest({url: `https://api.example.com/data?page=${page}`}, (err, res) => {
    pm.test(`Page ${page} has 10 items`, () => {
      pm.expect(res.json().items.length).to.eql(10);
    });
  });
}

💡 Hint

Consider where to place pm.test to properly register each test with a descriptive name.

Option D correctly wraps each asynchronous response assertion inside a pm.test with a descriptive name. Option D lacks pm.test so assertions are not reported as tests. Option D incorrectly nests pm.sendRequest inside pm.test, which does not wait for async calls properly. Option D uses a valid assertion but lacks pm.test so results are not reported as separate tests.