Test coverage metrics in Testing Fundamentals - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Statement Coverage

Which statement best describes statement coverage in software testing?

A It measures the percentage of functions that have been called during testing.

B It measures the percentage of all possible input combinations tested.

C It measures the percentage of executable statements in the code that have been executed by the tests.

D It measures the percentage of user interface elements tested.

💡 Hint

Think about how many lines of code your tests actually run.

Statement coverage counts how many lines of code (statements) are executed by tests compared to total executable lines.

❓ Predict Output

intermediate

Calculating Branch Coverage Output

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

def check_number(x):
    if x > 0:
        return 'Positive'
    else:
        return 'Non-positive'

Test cases run: check_number(5)

A 100%

B 50%

C 0%

D 75%

💡 Hint

Branch coverage counts how many decision branches are tested.

There are two branches: x > 0 true and false. Only the true branch is tested, so coverage is 50%.

❓ assertion

advanced

Assertion for Path Coverage

Which assertion correctly verifies that all paths in the following function have been tested?

def classify(num):
    if num > 0:
        if num % 2 == 0:
            return 'Positive Even'
        else:
            return 'Positive Odd'
    else:
        return 'Non-positive'

A assert path_coverage == 100

B assert path_coverage >= 50

C assert path_coverage == 75

D assert path_coverage == 0

💡 Hint

Count all unique paths through the nested if statements.

There are three paths: positive even, positive odd, and non-positive. Testing all means 100% path coverage.

🔧 Debug

advanced

Debugging Coverage Report Mismatch

A test suite reports 80% statement coverage but 100% branch coverage. What is the most likely cause?

A Tests cover all decision points but miss some simple statements outside decisions.

B The coverage tool is broken and reports wrong values.

C Branches are counted incorrectly, inflating branch coverage.

D Some statements are not executable but counted in statement coverage.

💡 Hint

Think about how branches and statements differ in coverage.

Branch coverage counts decision points; statement coverage counts all executable lines. Missing simple statements lowers statement coverage but not branch coverage.

❓ framework

expert

Integrating Coverage Metrics in CI Pipeline

Which approach best ensures that test coverage metrics are enforced automatically in a Continuous Integration (CI) pipeline?

A Run coverage tools locally only and ignore coverage in CI.

B Manually check coverage reports after each build and notify the team if low.

C Use coverage tools only for documentation, not for build decisions.

D Configure the CI to run tests and fail the build if coverage falls below a set threshold.

💡 Hint

Automation is key in CI pipelines.

Automatically failing builds when coverage is low enforces quality and prevents regressions.