Test utilities and helpers in Postman - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set a test variable named 'userId' with value 123.

Postman

pm.environment.set('[1]', 123);

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

Aresponse

Bstatus

CuserId

Dtoken

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong variable name like 'response' or 'status' instead of 'userId'.

Forgetting to put the variable name as a string.

The pm.environment.set function sets an environment variable. Here, the variable name should be 'userId' to store the value 123.

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'

A200

B500

C404

D201

Attempts:

3 left

💡 Hint

Common Mistakes

Using a wrong status code like 404 or 500.

Putting the status code in quotes which is not required.

The test checks if the response status code is exactly 200, which means success.

3fill in blank

hard

Fix the error in the code to parse JSON response body correctly.

Postman

let data = pm.response.[1]();

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

Aparse

Btext

Cbody

Djson

Attempts:

3 left

💡 Hint

Common Mistakes

Using text() which returns a string, not parsed JSON.

Trying to use parse() which is not a method of pm.response.

The pm.response.json() method parses the response body as JSON and returns the object.

4fill in blank

hard

Fill both blanks to write a test that checks if the response body has a property 'success' equal to true.

Postman

pm.test('Response has success true', function () { pm.expect(pm.response.[1]()).to.have.property('[2]', true); });

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

Ajson

Btext()

Csuccess

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using text() instead of json() for parsing.

Checking wrong property name like 'status' instead of 'success'.

We use pm.response.json() to get the response object, then check it has property 'success' with value true.

5fill in blank

hard

Fill all three blanks to write a test that checks if the response header 'Content-Type' includes 'json'.

Postman

pm.test('Content-Type is JSON', function () { pm.expect(pm.response.headers.get('[1]')).to.[2]('[3]'); });

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

AContent-Type

Binclude

Cjson

Dstatus

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong header name like 'status'.

Using wrong matcher like 'be' instead of 'include'.

Checking for wrong string instead of 'json'.

The test gets the 'Content-Type' header, then asserts it includes the string 'json' using to.include.

Practice

1. What is the main purpose of using test utilities and helpers in Postman tests?

easy

A. To increase the number of test cases automatically

B. To make API requests faster

C. To simplify writing and maintaining tests by reusing code

D. To change the API endpoint dynamically

Solution

1. Step 1: Understand the role of helpers

   Helpers are small reusable functions that simplify test code and avoid repetition.

2. Step 2: Identify the main benefit

   They make tests easier to write and maintain by reusing common logic.

3. Final Answer:

   To simplify writing and maintaining tests by reusing code -> Option C

4. Quick Check:

   Helpers simplify tests = A [OK]

Hint: Helpers reduce repeated code in tests [OK]

Common Mistakes:

• Thinking helpers speed up API requests
• Believing helpers create more test cases automatically
• Confusing helpers with dynamic endpoint changes

2. Which of the following is the correct way to define a helper function in Postman test scripts?

easy

A. checkStatus(response) => response.status == 200

B. def checkStatus(response): return response.code == 200

C. var checkStatus = response => { response.code = 200 }

D. function checkStatus(response) { return response.code === 200; }

Solution

1. Step 1: Identify JavaScript syntax in Postman

   Postman test scripts use JavaScript, so function keyword is correct.

2. Step 2: Check function correctness

   function checkStatus(response) { return response.code === 200; } defines a function that returns true if response.code equals 200, which is valid.

3. Final Answer:

   function checkStatus(response) { return response.code === 200; } -> Option D

4. Quick Check:

   JavaScript function syntax = C [OK]

Hint: Use JavaScript function keyword for helpers [OK]

Common Mistakes:

• Using Python syntax in Postman scripts
• Using arrow function but with assignment errors
• Using single equals instead of triple equals

3. Given the helper function below, what will be the output of pm.test('Check status', () => { pm.expect(isSuccess({code: 200})).to.be.true; });?

function isSuccess(response) {
  return response.code === 200;
}

medium

A. Test passes because response code is 200

B. Test fails because response code is not 200

C. Syntax error in helper function

D. Runtime error due to undefined response

Solution

1. Step 1: Analyze helper function behavior

   The function returns true if response.code equals 200, which it does here.

2. Step 2: Evaluate test assertion

   The test expects isSuccess to be true, so the assertion passes.

3. Final Answer:

   Test passes because response code is 200 -> Option A

4. Quick Check:

   response.code === 200 -> true -> test passes [OK]

Hint: Check helper return value matches assertion [OK]

Common Mistakes:

• Assuming test fails without checking code value
• Confusing syntax error with correct JavaScript
• Thinking response is undefined when it is provided

4. You wrote this helper function in Postman tests but it throws an error:

function isValid(response) {
  return response.status = 200;
}

What is the error and how to fix it?

medium

A. Use '===' instead of '=' for comparison in return statement

B. Change function to arrow syntax

C. Remove the return keyword

D. Rename function to start with uppercase letter

Solution

1. Step 1: Identify assignment vs comparison

   The code uses '=' which assigns value instead of comparing.

2. Step 2: Correct the operator

   Replace '=' with '===' to compare response.status to 200.

3. Final Answer:

   Use '===' instead of '=' for comparison in return statement -> Option A

4. Quick Check:

   Comparison needs '===' not '=' [OK]

Hint: Use triple equals for comparisons in helpers [OK]

Common Mistakes:

• Confusing assignment '=' with comparison '==='
• Thinking arrow function fixes this error
• Removing return breaks function output

5. You want to create a helper that checks if a JSON response has a non-empty data array. Which helper function below correctly implements this check?

hard

A. function hasData(response) { return response.data == undefined; }

B. function hasData(response) { return Array.isArray(response.data) && response.data.length > 0; }

C. function hasData(response) { return response.data !== null; }

D. function hasData(response) { return response.data.length >= 0; }

Solution

1. Step 1: Check if response.data is an array

   Use Array.isArray to confirm data is an array.

2. Step 2: Verify array is not empty

   Check that length is greater than zero to ensure non-empty.

3. Final Answer:

   function hasData(response) { return Array.isArray(response.data) && response.data.length > 0; } -> Option B

4. Quick Check:

   Array check + length > 0 = D [OK]

Hint: Check array type and length > 0 for non-empty data [OK]

Common Mistakes:

• Only checking length without confirming array type
• Checking for null but ignoring empty arrays
• Using == undefined which is incorrect here