Testing and quality assurance in Intro to Computing - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding the Purpose of Unit Testing

Which of the following best describes the main purpose of unit testing in software development?

A To test the entire software system as a whole to find integration issues

B To test individual parts of the code to ensure each part works correctly

C To check the software's performance under heavy user load

D To verify the software's user interface looks attractive

💡 Hint

Think about testing small pieces of code separately before combining them.

Unit testing focuses on testing small, individual parts of the code (units) to make sure each part works as expected before integrating them.

❓ trace

intermediate

Trace the Result of a Simple Test Case

Consider a function that adds two numbers. A test case checks if add(2, 3) returns 5. What is the result of this test case?

Intro to Computing

def add(a, b):
    return a + b

result = add(2, 3)
expected = 5
passed = (result == expected)
print(passed)

A True

B False

C TypeError

D SyntaxError

💡 Hint

Check if the function returns the expected sum.

The function correctly adds 2 and 3 to get 5, so the test passes and prints True.

❓ identification

advanced

Identify the Type of Testing from Description

Which type of testing is described by the following: Testing how different parts of a program work together after unit testing is done?

A Regression testing

B System testing

C Acceptance testing

D Integration testing

💡 Hint

Think about testing combined parts rather than the whole system.

Integration testing checks how different units work together after they have been tested individually.

❓ Comparison

advanced

Compare Manual Testing and Automated Testing

Which statement correctly compares manual testing and automated testing?

A Automated testing requires writing code to run tests repeatedly without human intervention

B Manual testing is faster and more reliable than automated testing

C Manual testing can run thousands of tests quickly without errors

D Automated testing cannot be used for regression testing

💡 Hint

Consider which testing type uses scripts or programs to run tests.

Automated testing uses scripts to run tests repeatedly and consistently without needing a person to do it each time.

🧠 Conceptual

expert

Understanding Regression Testing Importance

Why is regression testing important after fixing a bug in software?

A To improve the software's user interface design

B To test only the new features added after the bug fix

C To check if the bug fix caused new problems in other parts of the software

D To reduce the software's file size

💡 Hint

Think about what might happen when you change one part of a program.

Regression testing ensures that fixing one bug does not accidentally break other parts of the software.

Practice

1. What is the main purpose of testing in software development?

easy

A. To check if the software works as expected

B. To design the user interface

C. To write the software code

D. To deploy the software to users

Solution

1. Step 1: Understand the role of testing

   Testing is done to verify that software behaves correctly and meets requirements.

2. Step 2: Compare options with testing purpose

   Only To check if the software works as expected describes checking software functionality, which matches testing's main goal.

3. Final Answer:

   To check if the software works as expected -> Option A

4. Quick Check:

   Testing = Check software works [OK]

Hint: Testing means checking software behavior matches expectations [OK]

Common Mistakes:

• Confusing testing with coding
• Thinking testing is deployment
• Mixing testing with design tasks

2. Which of the following is the correct syntax to write a test case name in many testing frameworks?

easy

A. test_function

B. TestFunction

C. testFunction()

D. functionTest

Solution

1. Step 1: Identify common test naming conventions

   Many testing frameworks use lowercase with underscores for test case names, like test_function.

2. Step 2: Compare options with naming style

   test_function matches the common snake_case style used in tests, while others do not follow typical test naming.

3. Final Answer:

   test_function -> Option A

4. Quick Check:

   Test case names often use snake_case [OK]

Hint: Test names usually use lowercase with underscores [OK]

Common Mistakes:

• Using camelCase or PascalCase for test names
• Omitting 'test' prefix in test names
• Confusing function names with test names

3. Consider this pseudocode for a test checking if a number is positive:

function testIsPositive() {
  input = -5
  result = isPositive(input)
  assert(result == false)
}

What will the test result be if isPositive returns true for negative numbers by mistake?

medium

A. Test passes successfully

B. Test is skipped automatically

C. Test causes a runtime error

D. Test fails because assertion is false

Solution

1. Step 1: Understand the test logic

   The test expects isPositive(-5) to return false. The assertion checks if result equals false.

2. Step 2: Analyze the wrong function behavior

   If isPositive wrongly returns true for -5, the assertion result == false fails.

3. Final Answer:

   Test fails because assertion is false -> Option D

4. Quick Check:

   Wrong output causes assertion failure [OK]

Hint: If output differs from expected, assertion fails [OK]

Common Mistakes:

• Assuming test passes despite wrong output
• Confusing assertion failure with runtime error
• Thinking test skips on failure

4. A developer wrote this test code:

def test_divide():
  result = divide(10, 0)
  assert(result == 0)

What is the main problem with this test?

medium

A. It has a syntax error in assert

B. It uses wrong variable names

C. It does not check for division by zero error

D. It tests the wrong function

Solution

1. Step 1: Understand division by zero behavior

   Dividing by zero usually causes an error or exception, not a result of zero.

2. Step 2: Analyze the test assertion

   The test expects result to be zero, but it should check if an error is raised instead.

3. Final Answer:

   It does not check for division by zero error -> Option C

4. Quick Check:

   Division by zero needs error handling test [OK]

Hint: Division by zero should raise error, not return zero [OK]

Common Mistakes:

• Assuming divide returns zero on zero divisor
• Ignoring exception handling in tests
• Confusing syntax errors with logic errors

5. A software team wants to improve overall quality by combining testing with good development practices. Which approach best describes quality assurance?

hard

A. Only running automated tests before release

B. Using testing plus code reviews, documentation, and process checks

C. Writing code without any tests to save time

D. Ignoring user feedback after software release

Solution

1. Step 1: Define quality assurance scope

   Quality assurance (QA) includes testing and also good practices like code reviews, documentation, and process improvements.

2. Step 2: Evaluate options against QA definition

   Using testing plus code reviews, documentation, and process checks covers testing plus other practices, matching QA's broad approach. Others focus only on testing or ignore quality.

3. Final Answer:

   Using testing plus code reviews, documentation, and process checks -> Option B

4. Quick Check:

   QA = Testing + good practices [OK]

Hint: QA means testing plus good development practices [OK]

Common Mistakes:

• Thinking QA is only testing
• Skipping documentation and reviews
• Ignoring user feedback importance