Statement coverage in Testing Fundamentals - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Statement Coverage

Which of the following best describes statement coverage in software testing?

A It measures the percentage of executable statements in the code that have been executed by the test cases.

B It measures the percentage of decision outcomes (true/false) tested in the code.

C It measures the number of test cases executed during testing.

D It measures the time taken to execute all test cases.

💡 Hint

Think about what part of the code is actually run during testing.

Statement coverage checks if every line of code has been run at least once by the tests. It does not focus on decision outcomes or test case counts.

❓ Predict Output

intermediate

Calculate Statement Coverage Percentage

Given the following code and test cases, what is the statement coverage percentage?

def check_number(x):
    if x > 0:
        print("Positive")
    else:
        print("Non-positive")

# Test cases:
check_number(5)

A 25%

B 50%

C 100%

D 75%

💡 Hint

Count how many lines run when check_number(5) is called.

There are 4 executable statements: the if, the print("Positive"), the else, and print("Non-positive"). Only the if and print("Positive") run, so 2 out of 4 lines = 50% coverage.

❓ assertion

advanced

Assertion for Full Statement Coverage

Which assertion correctly verifies that a test suite achieves 100% statement coverage for the following function?

def is_even(n):
    if n % 2 == 0:
        return True
    else:
        return False

A assert statement_coverage(is_even_tests) == 0

B assert statement_coverage(is_even_tests) < 100

C assert statement_coverage(is_even_tests) >= 50

D assert statement_coverage(is_even_tests) == 100

💡 Hint

Full coverage means all lines run at least once.

To confirm 100% statement coverage, the assertion must check that coverage equals 100%. Other options are incorrect because they allow partial or no coverage.

🔧 Debug

advanced

Debugging Statement Coverage Measurement

Consider this test code measuring statement coverage. It reports 80% coverage, but the tester expects 100%. What is the likely cause?

def foo(x):
    if x > 0:
        print("Positive")
    else:
        print("Zero or Negative")

# Test cases
foo(1)
# Coverage measured here

A The function foo has a syntax error causing incomplete coverage.

B The print statements cause the coverage tool to fail.

C The test cases do not cover the else branch, so some statements are not executed.

D The coverage tool only measures function calls, not statements.

💡 Hint

Think about which lines run when foo(1) is called.

Calling foo(1) only runs the if branch, so the else branch statements are never executed, causing less than 100% coverage.

❓ framework

expert

Integrating Statement Coverage in Automated Testing

Which option correctly describes how to integrate statement coverage measurement into an automated Python test suite using pytest and coverage.py?

A Run tests with <code>coverage run -m pytest</code> then generate report with <code>coverage report</code>.

B Add <code>assert coverage == 100</code> inside each test function manually.

C Run tests with <code>pytest --coverage</code> without installing any extra tools.

D Use <code>pytest-cov</code> but coverage reports are generated automatically without any commands.

💡 Hint

Think about the standard commands to run coverage with pytest.

The correct way is to run tests under coverage using coverage run -m pytest and then generate a coverage report with coverage report. Option A is invalid because pytest alone does not support --coverage without plugins. Option A is incorrect because coverage is measured externally, not by assertions. Option A is wrong because reports require explicit commands.