What is the meaning of the message “There is no coverage information to report” for decision coverage and when does it occur in Simulink Coverage R2023a?

If the model coverage is analyzed and the option 'decision coverage' (branch coverage) is selected to be reported then the report shows for some models this message:

“There is no coverage information to report”

Can we assume that the model contains only a single branch and hence there are no coverage results to be reported?

That would mean the model coverage is assumed to 100 % because a single branch is always covered by any test case. Isn't it?

Answer 1

[MathWorks Support Team]

We will see the message "There is no coverage information to report" in the following cases:

1. All the blocks in the model do not receive coverage. Please see the link for the blocks that do not get coverage:

https://www.mathworks.com/help/releases/R2023b/slcoverage/ug/model-objects-that-do-not-receive-coverage.html

2. If there are blocks in the model that get coverage and those are excluded via coverage filter - as mentioned here:

https://www.mathworks.com/help/releases/R2023b/slcoverage/ug/filter-types-of-code-coverage-outcomes.html

Even if there is only a single branch in the model and we select decision coverage, the coverage report will consist of 

- execution metric details 

- and decision metrics reported as N/A instead of this message.

Looking at the above-mentioned cases, in my opinion, inferring this message as full coverage may not always be true.