Conditional request execution (setNextRequest) in Postman - Test Execution Trace

Test Overview

This test checks if the Postman collection runs the next request conditionally based on the response of the current request. It verifies that setNextRequest correctly directs the flow.

Test Code - Postman

Postman

pm.test("Check response status and set next request", function () {
    pm.response.to.have.status(200);
    const jsonData = pm.response.json();
    if (jsonData.success === true) {
        pm.setNextRequest("Request B");
    } else {
        pm.setNextRequest(null); // stops the run
    }
});

Execution Trace - 5 Steps

Step	Action	System State	Assertion	Result
1	Test starts and sends 'Request A' to the server	Postman sends HTTP request 'Request A' and waits for response	—	PASS
2	Postman receives response for 'Request A'	Response status 200 and JSON body received	Check response status is 200	PASS
3	Test script parses JSON response and checks if 'success' is true	JSON parsed, 'success' field evaluated	—	PASS
4	Based on condition, setNextRequest is called with 'Request B'	Postman sets next request to 'Request B'	—	PASS
5	Postman sends 'Request B' as next request	Request B sent to server	—	PASS

Failure Scenario

Failing Condition: Response status is not 200

Execution Trace Quiz - 3 Questions

What does setNextRequest("Request B") do in this test?

A It tells Postman to run 'Request B' next

B It stops the collection run immediately

C It retries the current request

D It skips 'Request B' and runs the next request

Key Result

Use setNextRequest to control the flow of requests dynamically based on response data, enabling conditional testing scenarios in Postman collections.

Practice

1. What is the main purpose of pm.setNextRequest() in Postman?

easy

A. To decide which request runs next based on a condition

B. To send the current request multiple times automatically

C. To stop the entire collection run immediately

D. To reset all environment variables to default values

Solution

1. Step 1: Understand the function of pm.setNextRequest()

   This function controls the flow of requests by specifying which request should run next.

2. Step 2: Compare with other options

   Options B, C, and D describe different actions not related to controlling the next request.

3. Final Answer:

   To decide which request runs next based on a condition -> Option A

4. Quick Check:

   pm.setNextRequest() controls next request execution [OK]

Hint: Remember: setNextRequest controls the next request flow [OK]

Common Mistakes:

• Thinking it repeats the current request
• Confusing it with stopping the collection run
• Assuming it resets variables

2. Which of the following is the correct syntax to set the next request named "Login" in a Postman test script?

easy

A. pm.setNextRequest(Login);

B. pm.setNextRequest("Login");

C. pm.setNextRequest('Login');

D. pm.setNextRequest(Login')

Solution

1. Step 1: Check the syntax for string argument

   The request name must be passed as a string in quotes. Both single or double quotes are valid, but must be paired correctly.

2. Step 2: Identify correct option

   pm.setNextRequest("Login"); uses double quotes correctly. pm.setNextRequest('Login'); also uses single quotes correctly. Both are valid syntaxes. pm.setNextRequest(Login); lacks quotes, causing a syntax error. pm.setNextRequest(Login') has mismatched quotes.

3. Final Answer:

   pm.setNextRequest("Login"); -> Option B

4. Quick Check:

   Request name must be a quoted string [OK]

Hint: Always quote request names in setNextRequest() [OK]

Common Mistakes:

• Forgetting quotes around request name
• Mismatched or missing quotes
• Omitting semicolon at line end

3. Consider this test script in Postman after a request named "CheckStatus":

if (pm.response.code === 200) {
    pm.setNextRequest('ProcessData');
} else {
    pm.setNextRequest('ErrorHandler');
}

If the response code is 404, which request runs next?

medium

A. ErrorHandler

B. ProcessData

C. CheckStatus

D. No next request runs

Solution

1. Step 1: Analyze the condition

   The script checks if response code is 200. If true, it sets next request to 'ProcessData'. Otherwise, it sets to 'ErrorHandler'.

2. Step 2: Apply the response code 404

   Since 404 is not 200, the else block runs, setting next request to 'ErrorHandler'.

3. Final Answer:

   ErrorHandler -> Option A

4. Quick Check:

   404 ≠ 200, so next request = ErrorHandler [OK]

Hint: If condition false, else block sets next request [OK]

Common Mistakes:

• Assuming 404 triggers the if block
• Thinking current request repeats
• Ignoring else block logic

4. You wrote this test script in Postman:

if (pm.response.code = 200) {
    pm.setNextRequest('NextStep');
} else {
    pm.setNextRequest('Stop');
}

What is the problem with this script?

medium

A. Request names should not be in quotes

B. Missing semicolon after pm.response.code

C. pm.setNextRequest cannot be used inside if statements

D. Using assignment (=) instead of comparison (===) in the if condition

Solution

1. Step 1: Identify the if condition error

   The condition uses single equals (=), which assigns 200 to pm.response.code instead of comparing it.

2. Step 2: Understand consequences

   This causes a bug: the if condition always evaluates to true, and response code is overwritten.

3. Final Answer:

   Using assignment (=) instead of comparison (===) in the if condition -> Option D

4. Quick Check:

   Use === for comparison, not = [OK]

Hint: Use === for comparison, not = assignment [OK]

Common Mistakes:

• Confusing = with === in conditions
• Removing quotes from request names
• Thinking setNextRequest can't be conditional

5. You want to create a Postman flow where if a variable userExists is true, the next request is "GetUserData", else the flow stops. Which script correctly implements this in the test tab?

hard

A. if (pm.variables.get('userExists') === true) {
pm.setNextRequest('GetUserData');
} else {
pm.setNextRequest(null);
}

B. if (pm.variables.get('userExists') == 'true') {
pm.setNextRequest('GetUserData');
} else {
pm.setNextRequest('Stop');
}

C. if (pm.variables.get('userExists')) {
pm.setNextRequest('GetUserData');
} else {
pm.setNextRequest(null);
}

D. if (pm.variables.get('userExists') === 'true') {
pm.setNextRequest('GetUserData');
} else {
pm.setNextRequest(null);
}

Solution

1. Step 1: Understand variable type and condition

   pm.variables.get returns a string or boolean depending on how set. Using it directly in if checks truthiness correctly.

2. Step 2: Check stopping the flow

   Setting pm.setNextRequest(null) stops the collection run, which matches the requirement to stop if userExists is false.

3. Step 3: Evaluate options

   if (pm.variables.get('userExists')) { pm.setNextRequest('GetUserData'); } else { pm.setNextRequest(null); } uses direct truthiness check and null to stop, which is correct. Options A and C compare strictly to boolean or string which may fail if variable type differs. if (pm.variables.get('userExists') == 'true') { pm.setNextRequest('GetUserData'); } else { pm.setNextRequest('Stop'); } tries to set next request to 'Stop' which is not a request name and won't stop the flow.

4. Final Answer:

   if (pm.variables.get('userExists')) { pm.setNextRequest('GetUserData'); } else { pm.setNextRequest(null); } -> Option C

5. Quick Check:

   Use truthy check and null to stop flow [OK]

Hint: Use null in setNextRequest to stop flow [OK]

Common Mistakes:

• Comparing variable to string 'true' instead of boolean
• Setting next request to a non-existent name to stop
• Not using null to stop the collection run