Why Postman is essential for API testing - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to send a GET request in Postman.

Postman

pm.sendRequest({ url: [1], method: 'GET' }, function (err, res) { pm.expect(err).to.be.null; });

Drag options to blanks, or click blank then click option'

A'POST'

B'PUT'

C'https://api.example.com/data'

D'DELETE'

Attempts:

3 left

💡 Hint

Common Mistakes

Using HTTP methods instead of URL in the URL field.

The URL must be a valid API endpoint string to send a GET request.

2fill in blank

medium

Complete the code to check if the response status code is 200.

Postman

pm.test('Status code is 200', function () { pm.response.to.have.status([1]); });

Drag options to blanks, or click blank then click option'

A301

B404

C500

D200

Attempts:

3 left

💡 Hint

Common Mistakes

Using error codes like 404 or 500 instead of 200.

Status code 200 means the request was successful.

3fill in blank

hard

Fix the error in the assertion to check if the response body contains the key 'userId'.

Postman

pm.test('Response has userId', function () { pm.expect(pm.response.json()).to.have.property([1]); });

Drag options to blanks, or click blank then click option'

A'userId'

Buserid

CuserId

Duser_id

Attempts:

3 left

💡 Hint

Common Mistakes

Using unquoted property names causing syntax errors.

The property name must be a string, so it needs quotes around 'userId'.

4fill in blank

hard

Fill both blanks to extract the 'name' from the JSON response and check if it equals 'John'.

Postman

const name = pm.response.json().[1];
pm.test('Name is John', function () { pm.expect(name).[2]('John'); });

Drag options to blanks, or click blank then click option'

Aname

Bto.equal

Cto.eql

Dusername

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong property names or incorrect assertion methods.

Access the 'name' property and use 'to.equal' to check exact equality.

5fill in blank

hard

Fill all three blanks to create a test that checks if the response time is less than 500ms and the response has a header 'Content-Type' with value 'application/json'.

Postman

pm.test('Response time and header check', function () {
  pm.expect(pm.response.responseTime).[1](500);
  pm.expect(pm.response.headers.get([2])).[3]('application/json');
});

Drag options to blanks, or click blank then click option'

Ato.be.below

B'Content-Type'

Cto.equal

Dto.be.above

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong assertion methods or header names without quotes.

Use 'to.be.below' to check response time less than 500ms, get the 'Content-Type' header as a string, and check it equals 'application/json'.

Practice

1. Why is Postman considered essential for API testing?

easy

A. It replaces the need for any backend development.

B. It is only used for designing websites.

C. It allows easy and fast testing of APIs without coding.

D. It is a tool for creating mobile apps.

Solution

1. Step 1: Understand Postman's purpose

   Postman is designed to test APIs quickly and easily, especially without needing to write code.

2. Step 2: Compare options with Postman's features

   Options B, C, and D describe unrelated uses, while A correctly states Postman's role in API testing.

3. Final Answer:

   It allows easy and fast testing of APIs without coding. -> Option C

4. Quick Check:

   Postman simplifies API testing = A [OK]

Hint: Postman tests APIs fast without coding [OK]

Common Mistakes:

• Confusing Postman with web design tools
• Thinking Postman replaces backend coding
• Assuming Postman is for mobile app creation

2. Which of the following is the correct way to send a GET request in Postman?

easy

A. Select GET method and enter URL

B. Select POST method and enter URL

C. Select DELETE method and enter URL

D. Select PUT method and enter URL

Solution

1. Step 1: Identify the HTTP method for retrieving data

   GET is the standard HTTP method used to request data from a server.

2. Step 2: Match the method with Postman selection

   In Postman, to send a GET request, you must select GET and enter the URL.

3. Final Answer:

   Select GET method and enter URL -> Option A

4. Quick Check:

   GET method retrieves data = A [OK]

Hint: GET method is for fetching data [OK]

Common Mistakes:

• Choosing POST instead of GET for data retrieval
• Confusing DELETE or PUT with GET
• Not selecting any HTTP method

3. Consider this Postman test script snippet:

pm.test("Status code is 200", function () {
    pm.response.to.have.status(200);
});

What will be the test result if the API response status is 404?

medium

A. Test will pass because 404 is a valid status

B. Test will fail because status is not 200

C. Test will error due to syntax mistake

D. Test will be skipped automatically

Solution

1. Step 1: Understand the test condition

   The test checks if the response status code equals 200.

2. Step 2: Compare actual status with expected

   The actual status is 404, which does not match 200, so the test fails.

3. Final Answer:

   Test will fail because status is not 200 -> Option B

4. Quick Check:

   Status 404 ≠ 200 means test fails = C [OK]

Hint: Test passes only if status matches expected [OK]

Common Mistakes:

• Assuming 404 is acceptable status for this test
• Thinking syntax error causes failure
• Believing test skips on mismatch

4. You wrote this Postman test:

pm.test("Response has userId", function () {
    pm.expect(pm.response.json().userId).to.exist;
});

But the test always fails. What is the most likely reason?

medium

A. The response JSON does not contain the key 'userId'.

B. The test syntax is incorrect and causes error.

C. Postman does not support JSON response testing.

D. The API endpoint URL is missing.

Solution

1. Step 1: Analyze the test code

   The test checks if the JSON response has a key named 'userId'.

2. Step 2: Identify why test fails

   If the test fails, it means 'userId' is missing in the response JSON, not a syntax error.

3. Final Answer:

   The response JSON does not contain the key 'userId'. -> Option A

4. Quick Check:

   Missing key in JSON causes test failure = B [OK]

Hint: Check if JSON key exists in response [OK]

Common Mistakes:

• Assuming syntax error causes failure
• Believing Postman can't test JSON
• Ignoring API endpoint correctness

5. You want to automate running multiple API tests and share results with your team. Which Postman feature helps achieve this?

hard

A. Using Postman only for API design, not testing.

B. Manually sending requests one by one and emailing screenshots.

C. Writing API tests only in external code editors without Postman.

D. Using Postman Collections with automated test scripts and sharing via Postman Cloud.

Solution

1. Step 1: Identify automation and sharing features in Postman

   Postman Collections allow grouping API requests with tests, which can be run automatically and shared via Postman Cloud.

2. Step 2: Compare options for automation and sharing

   Using Postman Collections with automated test scripts and sharing via Postman Cloud describes this feature correctly; others describe manual or unrelated approaches.

3. Final Answer:

   Using Postman Collections with automated test scripts and sharing via Postman Cloud. -> Option D

4. Quick Check:

   Collections + automation + sharing = D [OK]

Hint: Use Collections for automation and sharing [OK]

Common Mistakes:

• Thinking manual testing is automation
• Ignoring Postman's sharing features
• Confusing Postman with external editors only