Statement coverage, also known as line coverage, is a metric used in white-box testing to measure the percentage of executable statements in the source code that have been executed by the test suite. Achieving a certain percentage of statement coverage means that an equivalent percentage of the executable statements in the code have been executed during testing.
For example, achieving 80% statement coverage indicates that 80% of the lines of code have been run through during the testing process. This metric helps in identifying parts of the code that have not been tested and may contain undetected defects.
It's important to note that achieving high statement coverage does not necessarily guarantee that all possible paths or scenarios within the code are tested, nor does it ensure the detection of all types of defects. Other coverage metrics, such as branch coverage or condition coverage, might also be necessary to achieve a more thorough testing process.
References:
* The official ISTQB CTFL syllabus clearly defines statement coverage and explains that it ensures that the corresponding percentage of all executable statements have been tested.