Authentication testing in Testing Fundamentals - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the primary goal of authentication testing?

Choose the best description of what authentication testing aims to verify in a software system.

A To test if the system can handle multiple users simultaneously without crashing.

B To check if the system correctly identifies and verifies users before granting access.

C To verify that the system encrypts all user data during transmission.

D To ensure the system's user interface is easy to navigate.

💡 Hint

Think about what authentication means in everyday life, like showing an ID to prove who you are.

Authentication testing focuses on verifying that the system correctly identifies users before allowing access. It is about confirming identity, not about performance, encryption, or UI.

❓ Predict Output

intermediate

What is the output of this authentication check code?

Given the following Python code simulating a simple authentication check, what will be printed?

Testing Fundamentals

def authenticate(user, password):
    valid_users = {'alice': 'pass123', 'bob': 'qwerty'}
    if user in valid_users and valid_users[user] == password:
        return 'Access granted'
    else:
        return 'Access denied'

print(authenticate('bob', 'qwerty'))

A Access denied

B KeyError

C Access granted

D None

💡 Hint

Check if the username and password match the dictionary entries.

The username 'bob' exists in the dictionary with password 'qwerty', so the function returns 'Access granted'.

❓ assertion

advanced

Which assertion correctly tests failed login attempt?

You want to write a test to check that a login function returns False when given wrong credentials. Which assertion is correct?

Testing Fundamentals

def login(user, password):
    return user == 'admin' and password == 'secret'

# Choose the correct assertion to test login('admin', 'wrongpass')

A assert login('admin', 'wrongpass') == False

B assert login('admin', 'wrongpass') != False

C assert login('admin', 'wrongpass') is None

D assert login('admin', 'wrongpass') == True

💡 Hint

Think about what the function returns when credentials are incorrect.

The login function returns False for wrong credentials, so the assertion must check for False.

🔧 Debug

advanced

Identify the bug in this authentication test code

This test is supposed to check that a user cannot login with an empty password. What is the bug?

Testing Fundamentals

def test_empty_password():
    result = login('user1', '')
    assert result == True

A The assertion expects True but should expect False for empty password.

B The login function is missing a return statement.

C The test function name should start with 'test_' to run.

D The password parameter should be None, not empty string.

💡 Hint

Think about what should happen if the password is empty.

The test expects login to succeed with empty password, which is incorrect. It should expect failure (False).

❓ framework

expert

Which test framework feature best supports authentication testing with multiple user roles?

You want to test authentication for different user roles (admin, guest, user) with various credentials. Which feature of a test framework helps organize and run these tests efficiently?

A Snapshot testing to compare UI changes after login.

B Mocking external services to simulate network delays.

C Code coverage reports to measure tested code percentage.

D Parameterized tests that run the same test logic with different inputs.

💡 Hint

Think about running the same test with different usernames and passwords.

Parameterized tests allow running one test multiple times with different data, perfect for testing multiple user roles and credentials.

Practice

1. What is the main goal of authentication testing in software testing?

easy

A. To verify that only valid users can access the system

B. To check the speed of the application

C. To test the user interface design

D. To validate database connections

Solution

1. Step 1: Understand authentication testing purpose

   Authentication testing focuses on verifying user identity before granting access.

2. Step 2: Compare options with this purpose

   Only To verify that only valid users can access the system matches this goal; others relate to different testing areas.

3. Final Answer:

   To verify that only valid users can access the system -> Option A

4. Quick Check:

   Authentication testing = verify valid users [OK]

Hint: Authentication = check valid user access [OK]

Common Mistakes:

• Confusing authentication with performance testing
• Thinking authentication tests UI elements
• Mixing authentication with database testing

2. Which of the following is the correct way to test a login form's authentication feature?

easy

A. Enter valid username and password, then check for successful login

B. Click random buttons without entering data

C. Only check if the login button is visible

D. Test the color of the login page background

Solution

1. Step 1: Identify valid test steps for authentication

   Testing authentication requires entering valid credentials and verifying access.

2. Step 2: Evaluate options for correctness

   Enter valid username and password, then check for successful login correctly describes this; others do not test authentication properly.

3. Final Answer:

   Enter valid username and password, then check for successful login -> Option A

4. Quick Check:

   Valid credentials test = successful login [OK]

Hint: Test with valid credentials for login success [OK]

Common Mistakes:

• Ignoring input fields and clicking randomly
• Testing only UI elements without input
• Confusing visual checks with authentication tests

3. Consider this test case for authentication:

Input: username='user1', password='wrongpass'
Expected: Login fails with error message 'Invalid credentials'

What will be the test result if the system allows login with these credentials?

medium

A. Test passes if error message is shown

B. Test passes because login is successful

C. Test is inconclusive without more data

D. Test fails because login should not succeed

Solution

1. Step 1: Analyze expected vs actual behavior

   The test expects login failure with an error message for wrong password.

2. Step 2: Compare actual system behavior

   If login succeeds with wrong password, it contradicts expected behavior, causing test failure.

3. Final Answer:

   Test fails because login should not succeed -> Option D

4. Quick Check:

   Wrong password login = test fail [OK]

Hint: Wrong password must fail login [OK]

Common Mistakes:

• Assuming any login success means pass
• Ignoring expected error messages
• Confusing test pass/fail logic

4. You wrote this test script for authentication:

def test_login():
    username = 'admin'
    password = 'admin123'
    result = login(username, password)
    assert result == False

What is the error in this test?

medium

A. The password variable is empty

B. The username variable is not defined

C. The assertion expects login to fail but credentials are valid

D. The login function is missing parentheses

Solution

1. Step 1: Understand test intent and data

   Username and password appear valid, so login should succeed (True).

2. Step 2: Check assertion correctness

   Assertion expects False (failure), which contradicts valid credentials, causing test error.

3. Final Answer:

   The assertion expects login to fail but credentials are valid -> Option C

4. Quick Check:

   Valid credentials expect True, not False [OK]

Hint: Match assertion with expected login result [OK]

Common Mistakes:

• Asserting wrong expected result
• Assuming variables undefined without checking
• Confusing function call syntax

5. You want to test a system that locks a user account after 3 failed login attempts. Which test case best verifies this feature?

hard

A. Login once with correct password and check access

B. Attempt login 3 times with wrong password, then check if account is locked

C. Try logging in with empty username and password

D. Check if password reset link is visible on login page

Solution

1. Step 1: Identify feature to test

   The feature locks account after 3 failed login attempts.

2. Step 2: Select test case matching feature

   Attempt login 3 times with wrong password, then check if account is locked tests exactly this by failing login 3 times and checking lock status.

3. Final Answer:

   Attempt login 3 times with wrong password, then check if account is locked -> Option B

4. Quick Check:

   3 failed attempts = account lock test [OK]

Hint: Test lock by 3 failed logins [OK]

Common Mistakes:

• Testing unrelated features like password reset
• Using correct password instead of failed attempts
• Ignoring the number of failed attempts