A Practical Guide to Testing Object-Oriented Software

Measuring Test Coverage

Recall that coverage is the metric that indicates the level of confidence we can have in our testing.

What Is to Be Covered?

There are a large number of attributes of a system that could be used to measure coverage. Fundamentally, there are two categories of these attributes: inputs and outputs. That is, we can measure how many of the possible inputs have been used in test cases and we can measure how many of the possible outputs that a system can produce have been produced during testing.

Traditionally, coverage has been viewed from the output perspective. Metrics such as the percentage of lines of code covered or the number of alternatives out of a decision that have been exercised are typical. We have worked to cover ...