SQL Test includes SQLCover, a code coverage tool written by Ed Elliott.

Enabling Code Coverage

To enable code coverage on a series of tests, make sure the Code Coverage checkbox is checked before running the tests.

You can now run your tests. When the run is complete, you will see a tab to the right of the test output giving you the overall coverage level for the tests that have been run. The tab contains a full breakdown of coverage by function / procedure, and highlights the statements actually executed in each function / procedure during the test run: