Default and conditional responses in Postman - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the test result of this Postman test script?

Given the following Postman test script, what will be the test result if the response status code is 404?

Postman

pm.test('Status code is 200 or 201', function () {
    pm.expect(pm.response.code).to.be.oneOf([200, 201]);
});

A Test fails because 404 is not in [200, 201]

B Test passes because 404 is considered a success

C Test throws an error due to invalid syntax

D Test is skipped automatically

💡 Hint

Check which status codes are accepted by the oneOf assertion.

The test expects the response code to be either 200 or 201. Since 404 is not in this list, the assertion fails and the test fails.

❓ assertion

intermediate

Which assertion correctly checks for a default JSON property in Postman?

You want to verify that the JSON response always contains a property named 'success' with a boolean value. Which assertion is correct?

A pm.expect(pm.response.json().success).to.be.a('boolean');

B pm.expect(pm.response.json().success).to.be.true || false;

C pm.expect(pm.response.json().success).to.equal('true');

D pm.expect(pm.response.json().success).to.be('boolean');

💡 Hint

Check the syntax for type checking in Postman assertions.

Option A correctly checks that the 'success' property is of boolean type. Option A wrongly compares to string 'true'. Option A is invalid syntax. Option A uses incorrect assertion syntax.

🧠 Conceptual

advanced

What happens if no conditional test matches in a Postman test script?

In a Postman test script, you have multiple conditional tests checking response codes 200, 201, and 404. What is the default behavior if the response code is 500 and no condition matches?

A No test runs and the test suite passes by default

B All tests fail automatically because no condition matched

C Postman throws a runtime error due to unmatched conditions

D Tests not matching conditions are skipped, but overall test result depends on other tests

💡 Hint

Think about how Postman handles tests that are not explicitly triggered.

Tests that do not run due to conditions are skipped. The overall test result depends on the tests that do run. Postman does not fail or error automatically if no condition matches.

🔧 Debug

advanced

Why does this Postman test script always fail?

Analyze the following Postman test script and identify why it always fails regardless of response status code: pm.test('Check status', () => { if (pm.response.code === 200) { pm.expect(true).to.be.true; } else if (pm.response.code === 404) { pm.expect(true).to.be.true; } });

Postman

pm.test('Check status', () => {
  if (pm.response.code === 200) {
    pm.expect(true).to.be.true;
  } else if (pm.response.code === 404) {
    pm.expect(true).to.be.true;
  }
});

A The test always fails because pm.expect(true).to.be.true is incorrect

B The test syntax is invalid causing failure

C The test fails when response code is neither 200 nor 404 because no assertion runs

D The test fails because pm.response.code is undefined

💡 Hint

What happens if the response code is 500?

If the response code is not 200 or 404, no assertion runs inside the test callback. Postman treats this as a failed test because no assertion was made.

❓ framework

expert

How to implement a default response handler in Postman tests?

You want to write a Postman test script that handles multiple response codes (200, 201, 404) with specific assertions and also has a default assertion for any other response code. Which script correctly implements this?

A

pm.test('Response code check', () => {
  pm.expect(pm.response.code).to.be.oneOf([200,201,404]);
});

B

pm.test('Response code check', () => {
  switch(pm.response.code) {
    case 200:
      pm.expect(pm.response.code).to.equal(200);
      break;
    case 201:
      pm.expect(pm.response.code).to.equal(201);
      break;
    case 404:
      pm.expect(pm.response.code).to.equal(404);
      break;
    default:
      pm.expect.fail(`Unexpected status code: ${pm.response.code}`);
  }
});

C

pm.test('Response code check', () => {
  if ([200,201,404].includes(pm.response.code)) {
    pm.expect(pm.response.code).to.be.oneOf([200,201,404]);
  }
});

D

pm.test('Response code check', () => {
  if (pm.response.code === 200) {
    pm.expect(pm.response.code).to.equal(200);
  } else if (pm.response.code === 201) {
    pm.expect(pm.response.code).to.equal(201);
  } else if (pm.response.code === 404) {
    pm.expect(pm.response.code).to.equal(404);
  } else {
    pm.expect(pm.response.code).to.be.oneOf([200,201,404]);
  }
});

💡 Hint

Look for a default case that fails the test explicitly.

Option B uses a switch with a default case that explicitly fails the test if the response code is unexpected. Options B, C, and D do not fail the test for unexpected codes properly.

Practice

1. What is the main purpose of using default and conditional responses in Postman tests?

easy

A. To send multiple requests at the same time

B. To change the API endpoint dynamically

C. To check different API responses in one test script

D. To automatically generate API documentation

Solution

1. Step 1: Understand the role of conditional responses

   Conditional responses allow testing different API replies based on conditions in one place.

2. Step 2: Identify the main purpose

   This helps verify various outcomes without writing separate tests for each response.

3. Final Answer:

   To check different API responses in one test script -> Option C

4. Quick Check:

   Default and conditional responses = test multiple replies [OK]

Hint: Think: one test script, many response checks [OK]

Common Mistakes:

• Confusing response testing with sending requests
• Assuming it changes API endpoints
• Mixing testing with documentation generation

2. Which of the following is the correct syntax to write a conditional test in Postman to check if the response status is 200?

easy

A. pm.test('Status is 200', () => { if (pm.response.code === 200) { pm.expect(true).to.be.true; } });

B. pm.test('Status is 200', () => { pm.expect(pm.response.code).to.equal(200); });

C. pm.test('Status is 200', () => pm.response.code == 200);

D. pm.test('Status is 200', () => { if (pm.response.status == 200) pm.expect(true); });

Solution

1. Step 1: Review Postman test syntax

   Postman uses pm.test with a callback function and pm.expect for assertions.

2. Step 2: Identify correct assertion for status code

   pm.expect(pm.response.code).to.equal(200) correctly asserts status code equals 200.

3. Final Answer:

   pm.test('Status is 200', () => { pm.expect(pm.response.code).to.equal(200); }); -> Option B

4. Quick Check:

   pm.expect with .to.equal(200) = correct syntax [OK]

Hint: Use pm.expect with .to.equal for exact value checks [OK]

Common Mistakes:

• Using '==' instead of .to.equal() in assertions
• Checking pm.response.status instead of pm.response.code
• Not calling pm.expect properly inside pm.test

3. Given this Postman test code, what will be the test result if the response status is 404?

pm.test('Check response', () => {
  if (pm.response.code === 200) {
    pm.expect(pm.response.json().success).to.be.true;
  } else {
    pm.expect(pm.response.code).to.equal(404);
  }
});

medium

A. Test passes because status is 404 and matches else condition

B. Test fails because success property is missing

C. Test throws an error due to missing JSON body

D. Test passes only if success is true

Solution

1. Step 1: Analyze the if-else condition with status 404

   Status 404 triggers the else block which asserts pm.response.code equals 404.

2. Step 2: Check assertion in else block

   pm.expect(pm.response.code).to.equal(404) will pass since status is 404.

3. Final Answer:

   Test passes because status is 404 and matches else condition -> Option A

4. Quick Check:

   404 status triggers else assertion = pass [OK]

Hint: Match status code to correct if/else branch [OK]

Common Mistakes:

• Assuming test fails due to missing success property
• Thinking JSON parsing fails on 404
• Ignoring else block assertions

4. Identify the error in this Postman test script that checks for a 201 status or a 400 error:

pm.test('Status check', () => {
  if (pm.response.code = 201) {
    pm.expect(pm.response.code).to.equal(201);
  } else if (pm.response.code = 400) {
    pm.expect(pm.response.json().error).to.exist;
  }
});

medium

A. No else block to handle other status codes

B. Missing pm.expect in the first if block

C. Incorrect JSON parsing method

D. Using assignment '=' instead of comparison '===' in if conditions

Solution

1. Step 1: Check if condition syntax

   The code uses '=' which assigns value instead of '===' for comparison.

2. Step 2: Understand impact of assignment in conditions

   Assignment always returns true, causing logic errors and wrong test behavior.

3. Final Answer:

   Using assignment '=' instead of comparison '===' in if conditions -> Option D

4. Quick Check:

   Use '===' for comparisons, not '=' [OK]

Hint: Use '===' for comparisons, '=' is assignment [OK]

Common Mistakes:

• Confusing '=' with '==' or '==='
• Ignoring that assignment returns a value
• Not validating all possible status codes

5. You want to write a Postman test that checks if the response status is 200 and the JSON body has a 'data' field, but if the status is 404, it should check for an 'error' message. Which code snippet correctly implements this conditional response test?

hard

A. pm.test('Conditional response test', () => {
if (pm.response.code === 200) {
pm.expect(pm.response.json().data).to.exist;
} else if (pm.response.code === 404) {
pm.expect(pm.response.json().error).to.exist;
} else {
pm.expect.fail('Unexpected status code');
}
});

B. pm.test('Conditional response test', () => {
pm.expect(pm.response.code === 200 && pm.response.json().data).to.exist;
pm.expect(pm.response.code === 404 && pm.response.json().error).to.exist;
});

C. pm.test('Conditional response test', () => {
if (pm.response.code = 200) {
pm.expect(pm.response.json().data).to.exist;
} else if (pm.response.code = 404) {
pm.expect(pm.response.json().error).to.exist;
}
});

D. pm.test('Conditional response test', () => {
pm.expect(pm.response.json().data || pm.response.json().error).to.exist;
});

Solution

1. Step 1: Check correct use of comparison operators

   pm.test('Conditional response test', () => { if (pm.response.code === 200) { pm.expect(pm.response.json().data).to.exist; } else if (pm.response.code === 404) { pm.expect(pm.response.json().error).to.exist; } else { pm.expect.fail('Unexpected status code'); } }); uses '===' for comparisons correctly. Using '=' causes assignment instead of comparison.

2. Step 2: Verify conditional logic and assertions

   The code checks 'data' field existence for status 200, 'error' for 404, and explicitly fails for unexpected codes using pm.expect.fail().

3. Step 3: Evaluate other options

   One option incorrectly combines status and field checks in single pm.expect statements, causing failures. Another does not condition on status codes at all.

4. Final Answer:

   pm.test('Conditional response test', () => { if (pm.response.code === 200) { pm.expect(pm.response.json().data).to.exist; } else if (pm.response.code === 404) { pm.expect(pm.response.json().error).to.exist; } else { pm.expect.fail('Unexpected status code'); } }); -> Option A

5. Quick Check:

   Use if-else with '===' and proper assertions [OK]

Hint: Use if-else with '===' and separate assertions [OK]

Common Mistakes:

• Using '=' instead of '===' in conditions
• Combining conditions inside one pm.expect
• Not handling unexpected status codes