What does decision coverage measure in testing?

Decision coverage measures the percentage of decision outcomes exercised by test cases. In software testing, a decision is a point in the code where the control flow can go in multiple directions based on the evaluation of a condition (such as an if statement, switch case, etc.). Each decision can have two or more outcomes (e.g., true or false).

By assessing decision coverage, testers ensure that all possible paths resulting from those decisions are exercised during testing. This helps verify that the software behaves as expected under various conditions, thereby improving the overall quality of the software. Achieving high decision coverage is vital for identifying potential flaws in the software's logic that could lead to defects when used in production.

The other options refer to different forms of code coverage or testing metrics. Condition outcomes pertain specifically to the individual components of a decision, while statement coverage focuses on the execution of lines of code. The total number of test cases that passed does not directly measure the effectiveness of the coverage of decision outcomes, as it does not provide insights into which decision paths have or haven’t been tested.