Static analysis tools in Testing Fundamentals - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Purpose of Static Analysis Tools

What is the primary purpose of static analysis tools in software testing?

A To analyze code without executing it to find potential errors

B To measure the performance of the software during execution

C To find bugs by running the program with test inputs

D To automatically fix bugs found during testing

💡 Hint

Think about tools that check code before running it.

Static analysis tools examine the source code without running it to detect errors, code smells, or security issues early.

❓ Predict Output

intermediate

Static Analysis Warning Example

Given the following Python code snippet, what warning would a static analysis tool most likely report?

Testing Fundamentals

def calculate_area(radius):
    pi = 3.14159
    area = pi * radius ** 2
    return area

result = calculate_area(5)
print(result)

unused_var = 10

A Unused variable 'unused_var' detected

B Division by zero error possible

C Syntax error due to missing colon

D Variable 'pi' used before assignment

💡 Hint

Look for variables declared but never used.

The variable 'unused_var' is declared but never used, which static analysis tools often warn about to help clean code.

❓ assertion

advanced

Static Analysis and Assertion Failures

Which statement about static analysis tools and assertion failures is correct?

A Static analysis tools replace the need for assertions in code

B Static analysis tools cannot detect assertion failures because assertions depend on runtime values

C Static analysis tools automatically fix assertion failures

D Static analysis tools can detect all assertion failures before runtime

💡 Hint

Consider when assertions are checked during program execution.

Assertions check conditions during runtime, so static analysis tools cannot detect failures that depend on actual runtime data.

🔧 Debug

advanced

Identifying Static Analysis Tool Output

Which output below is most likely produced by a static analysis tool scanning this JavaScript code?

Testing Fundamentals

function add(a, b) {
  return a + b;
}

let result = add(5);
console.log(result);

A No issues found

B Error: Syntax error missing semicolon

C Warning: Function 'add' called with 1 argument but expects 2

D Warning: Variable 'result' is unused

💡 Hint

Check function calls and argument counts.

The function 'add' expects two arguments, but is called with only one, which static analysis tools detect as a potential bug.

❓ framework

expert

Integrating Static Analysis in CI/CD Pipeline

Which approach best integrates static analysis tools into a CI/CD pipeline to improve code quality?

A Run static analysis only after deployment to production

B Run static analysis only on the main branch after merging

C Run static analysis manually once a month

D Run static analysis on every pull request before merging code

💡 Hint

Think about catching issues early in the development process.

Running static analysis on every pull request helps catch issues before code merges, improving quality and reducing bugs.

Practice

1. What is the main purpose of static analysis tools in software testing?

easy

A. To deploy the software to production

B. To execute the program and check its output

C. To test the user interface manually

D. To find errors in code without running the program

Solution

1. Step 1: Understand static analysis tools

   Static analysis tools examine code by reading it, not by running it.

2. Step 2: Compare options

   Only To find errors in code without running the program describes checking code without execution, which is the main purpose.

3. Final Answer:

   To find errors in code without running the program -> Option D

4. Quick Check:

   Static analysis = code check without run [OK]

Hint: Static analysis checks code without running it [OK]

Common Mistakes:

• Confusing static analysis with dynamic testing
• Thinking static analysis runs the program
• Mixing up manual UI testing with static analysis

2. Which of the following is a correct example of a static analysis tool?

easy

A. Selenium

B. ESLint

C. JUnit

D. Postman

Solution

1. Step 1: Identify static analysis tools

   ESLint is a tool that checks JavaScript code for errors and style issues without running it.

2. Step 2: Eliminate other options

   Selenium is for UI testing, JUnit is for unit testing (dynamic), Postman is for API testing.

3. Final Answer:

   ESLint -> Option B

4. Quick Check:

   ESLint = static analysis tool [OK]

Hint: ESLint is a popular static analysis tool for JavaScript [OK]

Common Mistakes:

• Choosing Selenium which is for dynamic UI testing
• Confusing JUnit with static analysis
• Selecting Postman which tests APIs dynamically

3. Consider this Python code snippet checked by a static analysis tool:

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

result = add(5, '3')

What issue will the static analysis tool most likely report?

medium

A. Type mismatch: adding int and str

B. Syntax error due to missing colon

C. Unused variable 'result'

D. No issues found

Solution

1. Step 1: Analyze the code for type errors

   The function adds two parameters. The call adds an integer 5 and a string '3', which is a type mismatch.

2. Step 2: Understand static analysis detection

   Static analysis tools detect type mismatches like adding int and str without running the code.

3. Final Answer:

   Type mismatch: adding int and str -> Option A

4. Quick Check:

   Static analysis finds type errors like int + str [OK]

Hint: Look for type mismatches in function calls [OK]

Common Mistakes:

• Thinking missing colon causes error (it is present)
• Ignoring type mismatch between int and string
• Assuming variable 'result' is unused error

4. A static analysis tool reports a warning: "Unused variable 'temp'" in this code:

def calculate(x):
    temp = x * 2
    return x + 1

What is the best fix?

medium

A. Add a print statement for 'temp' to use it

B. Rename 'temp' to 'result' to fix the warning

C. Remove the variable 'temp' since it is not used

D. Ignore the warning; it does not affect the code

Solution

1. Step 1: Understand the warning

   The variable 'temp' is assigned but never used, which wastes memory and may confuse readers.

2. Step 2: Choose the best fix

   Removing 'temp' cleans the code and resolves the warning. Renaming or printing does not solve the root cause.

3. Final Answer:

   Remove the variable 'temp' since it is not used -> Option C

4. Quick Check:

   Unused variables should be removed [OK]

Hint: Remove variables that are assigned but never used [OK]

Common Mistakes:

• Renaming variable without using it
• Adding print statements unnecessarily
• Ignoring warnings thinking they are harmless

5. You want to use a static analysis tool to improve code quality before testing. Which approach is best?

hard

A. Integrate static analysis into the development process early

B. Run static analysis only on production code

C. Use static analysis only for UI code

D. Run static analysis after all tests pass

Solution

1. Step 1: Understand when to use static analysis

   Static analysis is most effective when used early during development to catch errors before testing.

2. Step 2: Evaluate options

   Integrate static analysis into the development process early suggests integrating static analysis early, which improves code quality and reduces bugs later.

3. Final Answer:

   Integrate static analysis into the development process early -> Option A

4. Quick Check:

   Early static analysis improves code quality [OK]

Hint: Use static analysis early in development [OK]

Common Mistakes:

• Running static analysis only after tests
• Limiting static analysis to production code
• Applying static analysis only to UI code