koodikattavuuden

Koodikattavuus, also known as code coverage, is a metric used in software testing that measures the degree to which the source code of a program has been tested. It is typically expressed as a percentage. Higher code coverage generally indicates a lower risk of bugs and a more thoroughly tested application.

There are several types of code coverage, including statement coverage, branch coverage, condition coverage, and path coverage. Statement coverage tracks which lines of code have been executed. Branch coverage ensures that each possible branch of a control structure (like if-else statements or loops) has been tested. Condition coverage verifies that each boolean sub-expression within a conditional statement has been evaluated to both true and false. Path coverage is the most exhaustive, aiming to test every possible execution path through a program.

Code coverage tools work by instrumenting the source code, adding probes that record which parts of the code are executed during test runs. The results are then aggregated to produce a coverage report. While high code coverage can be a good indicator of test suite quality, it does not guarantee that all bugs have been found. It is possible to have high coverage without adequately testing edge cases or specific error conditions. Therefore, code coverage should be used as a complementary tool to other testing strategies, not as a sole measure of software quality.