Statement coverage in Testing Fundamentals - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to calculate statement coverage percentage.

Testing Fundamentals

coverage = (executed_statements / [1]) * 100

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

Aexecuted_statements

Btotal_statements

Ctotal_tests

Dfailed_statements

Attempts:

3 left

💡 Hint

Common Mistakes

Using executed_statements as denominator instead of total_statements

Using total_tests which is unrelated to statement count

The total number of statements is needed to calculate the coverage percentage.

2fill in blank

medium

Complete the code to check if all statements were executed.

Testing Fundamentals

if executed_statements [1] total_statements:
    print("All statements covered")

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

A<

B!=

C>

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using '<' or '>' which do not confirm full coverage

Using '!=' which checks for inequality

We check if executed statements equal total statements to confirm full coverage.

3fill in blank

hard

Fix the error in the code to correctly calculate coverage as a float.

Testing Fundamentals

coverage = executed_statements / [1]

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

Afloat(total_statements)

Bstr(total_statements)

Cint(total_statements)

Dtotal_statements

Attempts:

3 left

💡 Hint

Common Mistakes

Using int conversion which does not change type

Using str conversion which causes errors

Converting total_statements to float ensures floating-point division for accurate coverage.

4fill in blank

hard

Fill both blanks to create a dictionary of statement coverage for multiple modules.

Testing Fundamentals

coverage_dict = {module: executed[1] / total[2] for module, executed_statements, total_statements in data}

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

A_statements

B_tests

D_cases

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent suffixes like _tests or _cases

Mixing different suffixes for executed and total

The keys executed_statements and total_statements represent counts for coverage calculation.

5fill in blank

hard

Fill all three blanks to filter modules with coverage above 80%.

Testing Fundamentals

high_coverage = {module: coverage for module, coverage in coverage_dict.items() if coverage [1] [2] and coverage [3] 1.0}

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

A>

B0.8

C<=

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using equality operator which is too strict

Using wrong comparison directions

We select coverage greater than 0.8 and less than or equal to 1.0 to find high coverage modules.

Practice

1. What does statement coverage measure in software testing?

easy

A. The number of test cases written

B. The number of bugs found in the code

C. The time taken to run all tests

D. The percentage of code lines executed during testing

Solution

1. Step 1: Understand the definition of statement coverage

   Statement coverage measures how many lines of code are executed when tests run.

2. Step 2: Compare options to the definition

   Only The percentage of code lines executed during testing correctly describes statement coverage as the percentage of executed code lines.

3. Final Answer:

   The percentage of code lines executed during testing -> Option D

4. Quick Check:

   Statement coverage = executed code lines percentage [OK]

Hint: Statement coverage counts executed lines, not tests or bugs [OK]

Common Mistakes:

• Confusing statement coverage with number of test cases
• Thinking it measures bugs found
• Mixing it up with test execution time

2. Which of the following is the correct way to describe statement coverage in a test report?

easy

A. Statement coverage is the number of test cases executed.

B. Statement coverage is the percentage of code statements executed during testing.

C. Statement coverage is the total time taken to run all tests.

D. Statement coverage is the number of bugs found per test.

Solution

1. Step 1: Identify the correct definition for statement coverage in reports

   Statement coverage is reported as the percentage of code statements executed during tests.

2. Step 2: Match options to the correct definition

   Statement coverage is the percentage of code statements executed during testing. correctly states this; others confuse coverage with test count, time, or bugs.

3. Final Answer:

   Statement coverage is the percentage of code statements executed during testing. -> Option B

4. Quick Check:

   Statement coverage = % of executed statements [OK]

Hint: Coverage means percent of executed code lines, not test counts [OK]

Common Mistakes:

• Reporting coverage as number of tests
• Confusing coverage with test duration
• Mixing coverage with bug counts

3. Consider this code snippet:

if (x > 0) {
  print("Positive");
} else {
  print("Non-positive");
}

If a test runs with x = 5, what is the statement coverage?

medium

A. 100% because all lines run

B. 75% because some lines run

C. 50% because only the if block runs

D. 0% because no else block runs

Solution

1. Step 1: Count total statements in the code

   There are 4 statements: the if condition, print("Positive"), else, print("Non-positive").

2. Step 2: Identify executed statements when x=5

   The if condition and print("Positive") run; else and its print do not run. So 2 out of 4 statements run.

3. Final Answer:

   50% because only the if block runs -> Option C

4. Quick Check:

   Executed statements = 2/4 = 50% [OK]

Hint: Only executed lines count; else block skipped means less coverage [OK]

Common Mistakes:

• Assuming else block runs anyway
• Counting conditions as multiple statements
• Thinking coverage is always 100%

4. You have this code:

if (a == 10) {
  print("Ten");
}
print("Done");

A test runs with a = 5 but reports 100% statement coverage. What is wrong?

medium

A. The test did not execute the if block, so coverage cannot be 100%

B. The print("Done") statement was not executed

C. The test input is invalid

D. The coverage tool counts only executed lines, so 100% is correct

Solution

1. Step 1: Identify statements and their execution

   There are 3 statements: if condition, print("Ten"), and print("Done"). With a=5, the if block is skipped, so print("Ten") is not executed.

2. Step 2: Check coverage report validity

   Since one statement is not executed, coverage cannot be 100%. The report is incorrect or the test did not run as expected.

3. Final Answer:

   The test did not execute the if block, so coverage cannot be 100% -> Option A

4. Quick Check:

   Skipped statements mean coverage less than 100% [OK]

Hint: Skipped code means coverage less than 100%, check test inputs [OK]

Common Mistakes:

• Assuming coverage counts unexecuted lines
• Ignoring skipped if blocks
• Trusting coverage tool blindly

5. Given this code:

if (score >= 90) {
  grade = 'A';
} else if (score >= 80) {
  grade = 'B';
} else {
  grade = 'C';
}

Which test inputs will achieve 100% statement coverage?

hard

A. score = 95, score = 85, and score = 70

B. score = 95 and score = 85

C. score = 95 only

D. score = 70 only

Solution

1. Step 1: Identify all statements in the code

   There are 7 statements: 3 conditions and 4 assignments (grade = 'A', grade = 'B', grade = 'C', plus else blocks).

2. Step 2: Determine inputs to cover all branches

   To cover all statements, tests must run each branch: score=95 covers first if, score=85 covers else if, score=70 covers else.

3. Final Answer:

   score = 95, score = 85, and score = 70 -> Option A

4. Quick Check:

   All branches covered by three inputs = 100% coverage [OK]

Hint: Test all branches to cover all statements fully [OK]

Common Mistakes:

• Testing only some branches
• Assuming one input covers all
• Ignoring else branch coverage