When you enable Live Unit Testing, the Visual Studio code editor provides you sufficient information to notify of the changes that you are working on in the code coverage. It also provides you with real-time unit test results by displaying icons in the left-hand side bar. It's known as coverage visualization, and you can visualize it on a line-by-line basis in the editor:

• The blue dash () indicates that the line of executable code does not have any test coverage.
• The green check mark () indicates that the line of executable code is covered by passing unit test cases.
• The red cross mark () indicates that the line was executed, but at least one unit test case was failed.
• When you see a blue dash with a clock icon (), it indicates that the line of executable code does not have any test coverage at this moment, but it is processing the changes that have been made and is going to update the visualization with refreshed data.
• When a green check mark comes with a clock icon (), it indicates that the data is not up to date for the test case that passed earlier.
• The red cross mark with a clock icon () denotes a failed test case for which the data is not yet up-to-date. When processing the changes, the visualization will update automatically with new data.