Static analysis tools in Testing Fundamentals - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a static analysis tool that checks code style.

Testing Fundamentals

def check_code_style(code):
    issues = []
    if not code.endswith([1]):
        issues.append("Code should end with a newline.")
    return issues

Drag options to blanks, or click blank then click option'

A"\n"

B"\t"

C";"

D" "

Attempts:

3 left

💡 Hint

Common Mistakes

Using a tab or space instead of a newline character.

Forgetting to include quotes around the newline character.

The code style checker expects the code to end with a newline character \n. This is a common style rule.

2fill in blank

medium

Complete the code to detect unused variables in a simple code snippet.

Testing Fundamentals

def find_unused_vars(code_vars, used_vars):
    unused = [var for var in code_vars if var [1] used_vars]
    return unused

Drag options to blanks, or click blank then click option'

A==

Bin

Cnot in

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using in instead of not in, which would find used variables instead.

Using equality operators which don't check membership.

Unused variables are those declared but not used, so we check if each variable is not in the list of used variables.

3fill in blank

hard

Fix the error in the code that checks for function naming conventions.

Testing Fundamentals

def is_valid_function_name(name):
    return name.[1]("_") and name.islower()

Drag options to blanks, or click blank then click option'

Astartswith

Bendswith

Ccontains

Dfind

Attempts:

3 left

💡 Hint

Common Mistakes

Using endswith which checks the end of the string.

Using contains which is not a valid string method.

Function names should start with an underscore for private functions. The method startswith checks this correctly.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps variable names to their lengths only if length is greater than 3.

Testing Fundamentals

lengths = {var: [1] for var in variables if len(var) [2] 3}

Drag options to blanks, or click blank then click option'

Alen(var)

B>

C<

Dvar

Attempts:

3 left

💡 Hint

Common Mistakes

Using the variable name itself instead of its length.

Using less than < instead of greater than >.

The dictionary maps each variable name to its length using len(var). The condition filters names with length greater than 3 using >.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension that maps uppercase variable names to their values only if the value is positive.

Testing Fundamentals

result = [1]: [2] for [3], val in data.items() if val > 0

Drag options to blanks, or click blank then click option'

Avar.upper()

Bval

Cvar

Dkey

Attempts:

3 left

💡 Hint

Common Mistakes

Using key instead of var as loop variable.

Not converting variable names to uppercase for keys.

The dictionary keys are uppercase variable names using var.upper(). The values are val. The loop variable is var for the variable name.

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