Output block in Postman - Build an Automation Script

Verify the output block in Postman test script

Preconditions (2)

Step 1: Send the API request

Step 2: Go to the Tests tab in Postman

Step 3: Write a test script that captures the response body

Step 4: Use the output block to log the response status and body

Step 5: Run the request and observe the output block in the Postman console

✅ Expected Result: The Postman console shows the response status code and the response body logged correctly in the output block

Automation Requirements - Postman test scripts (JavaScript)

Assertions Needed:

Verify response status code is 200

Verify response body contains expected keys or values

Best Practices:

Use pm.response to access response data

Use console.log for output block logging

Write clear and simple assertions

Keep test scripts readable and maintainable

Automated Solution

Postman

pm.test('Status code is 200', () => {
    pm.response.to.have.status(200);
});

const responseBody = pm.response.json();
console.log('Response Status:', pm.response.code);
console.log('Response Body:', responseBody);

pm.test('Response body has userId', () => {
    pm.expect(responseBody).to.have.property('userId');
});

This script first checks if the response status code is 200 using pm.test and pm.response.to.have.status. Then it parses the response body as JSON and logs the status code and body to the Postman console using console.log, which acts as the output block. Finally, it asserts that the response body contains a key named userId. This approach helps verify the API response and outputs useful information for debugging.

Common Mistakes - 3 Pitfalls

Using console.log outside of test scripts

Not parsing response body before accessing properties

Hardcoding status code without assertion

Bonus Challenge

Now add data-driven testing with 3 different API endpoints and verify their status codes and output blocks

Show Hint

Practice

1. What does the Output block in Postman primarily display after running a request?

easy

A. The list of saved environments

B. The raw API request headers only

C. The Postman app settings and preferences

D. The results of test scripts and any console logs

Solution

1. Step 1: Understand the purpose of the Output block

   The Output block shows what happened after running a request, including test results and logs.

2. Step 2: Identify what is NOT shown in the Output block

   Settings, environments, or just headers are not shown here; only test results and logs appear.

3. Final Answer:

   The results of test scripts and any console logs -> Option D

4. Quick Check:

   Output block = test results + logs [OK]

Hint: Output block shows test results and logs only [OK]

Common Mistakes:

• Confusing Output block with environment settings
• Thinking it shows only request headers
• Assuming it displays saved collections

2. Which of the following is the correct way to log a message to the Output block in a Postman test script?

easy

A. log('Test passed')

B. print('Test passed')

C. console.log('Test passed')

D. echo('Test passed')

Solution

1. Step 1: Recall JavaScript logging syntax in Postman

   Postman test scripts use JavaScript, and console.log() is the standard way to log messages.

2. Step 2: Identify incorrect logging functions

   Functions like print(), log(), and echo() are not valid in Postman scripts.

3. Final Answer:

   console.log('Test passed') -> Option C

4. Quick Check:

   Use console.log() to log messages [OK]

Hint: Use console.log() to print messages in Output block [OK]

Common Mistakes:

• Using print() instead of console.log()
• Trying to use echo() which is not JavaScript
• Forgetting parentheses in console.log

3. Given this Postman test script:

pm.test('Status code is 200', () => {
    pm.response.to.have.status(200);
});
console.log('Test completed');

What will you see in the Output block after running the request if the response status is 200?

medium

A. Test failed and no message

B. Test passed and 'Test completed' message

C. Only 'Test completed' message

D. No output at all

Solution

1. Step 1: Analyze the test script behavior

   The test checks if the response status is 200. If true, the test passes.

2. Step 2: Understand console.log output

   The console.log prints 'Test completed' regardless of test result.

3. Final Answer:

   Test passed and 'Test completed' message -> Option B

4. Quick Check:

   Passing test + console.log message = Test passed and 'Test completed' message [OK]

Hint: Passing test shows pass + console.log output [OK]

Common Mistakes:

• Assuming console.log only shows on failure
• Thinking test fails if console.log runs
• Ignoring test result messages

4. You wrote this Postman test script:

pm.test('Response time is less than 200ms', () => {
    pm.expect(pm.response.responseTime).to.be.below(200);
});
console.log('Check complete');

But after running, the Output block shows no test results or logs. What is the most likely problem?

medium

A. The test script is not saved or attached to the request

B. The response time is exactly 200ms, so test is skipped

C. console.log is not supported in Postman

D. The Output block only shows errors, not passes

Solution

1. Step 1: Check why Output block is empty

   If no test results or logs appear, the script might not be running at all.

2. Step 2: Confirm script attachment and saving

   Scripts must be saved and attached to the request to run and show output.

3. Final Answer:

   The test script is not saved or attached to the request -> Option A

4. Quick Check:

   Unsaved script = no output [OK]

Hint: Always save and attach test scripts to see output [OK]

Common Mistakes:

• Thinking console.log is unsupported
• Assuming Output block hides passing tests
• Believing test skips on exact boundary values

5. You want to verify in Postman that a JSON response contains a key userId with value 5, and log 'User verified' only if the test passes. Which test script will correctly show this in the Output block?

hard

A. pm.test('UserId is 5', () => {
pm.expect(pm.response.json().userId).to.eql(5);
});
if(pm.response.json().userId === 5) console.log('User verified');

B. pm.test('UserId is 5', () => {
pm.expect(pm.response.json().userId).to.eql(5);
console.log('User verified');
});

C. if(pm.response.json().userId === 5) {
pm.test('UserId is 5', () => {});
console.log('User verified');
}

D. pm.test('UserId is 5', () => {
pm.expect(pm.response.json().userId).to.eql(5);
});
console.log('User verified');

Solution

1. Step 1: Understand conditional logging requirement

   pm.test callbacks always execute fully; assertions don't halt execution. Log only on pass requires a matching condition.

2. Step 2: Analyze options

   A: unconditional log after test - always logs.
   B: log inside pm.test - executes even if assertion fails.
   C: empty pm.test - no proper verification.
   D: proper assertion test + matching if condition - logs only if userId === 5 (test passes).

3. Final Answer:

   pm.test('UserId is 5', () => { pm.expect(pm.response.json().userId).to.eql(5); }); if(pm.response.json().userId === 5) console.log('User verified'); -> Option A

4. Quick Check:

   if() matching test condition = log only on pass [OK]

Hint: Use if() matching assertion after pm.test for log only on pass [OK]

Common Mistakes:

• Putting console.log inside pm.test (runs on fail too)
• Logging unconditionally outside pm.test
• Using empty pm.test callback