Why do I receive the following warning when using the CodeCoveragePlugin in MATLAB R2022b: "The code coverage metrics for the MATLAB source file might be outdated"?

We have a MATLAB code base that has been supported on MATLAB R2018b and R2019b. As part of test execution, we instruct the MATLAB test runner to collect coverage via the CodeCoveragePlugin. We recently updated the code base to support MATLAB R2022b, but when executing our test suite, we now receive this warning message:

Warning: The code coverage metrics for the MATLAB source file might be outdated. To produce an accurate coverage report, consider updating the P-file before running your coverage session.
Can you provide more details about this change in the Code Coverage implementation for MATLAB R2022b and why we receive this warning?

Answer 1

[MathWorks Support Team]

Code Coverage reporting requires an accurate copy of the source code which is obtained from the M file. In previous releases, you could silence the warning about the P-code being out of date by using the "touch" command on the P-file, but that did not ensure the files were consistent.

Beginning in MATLAB R2022a, the Code Coverage report shows function and statement coverage. Previous releases reported line coverage. As part of this work, the P-file validation is now more accurate. When the contents of the files don't match, the observed warning is produced. This lets you know that the report will not be correct. Please note that the report was incorrect in previous releases too, MATLAB just did not produce a warning about it. Now MATLAB tells you that the report is incorrect.

If you do not wish to see these warnings, you can suppress or turn off the warnings by following the instructions in the following documentation page:

https://www.mathworks.com/help/matlab/matlab_prog/suppress-warnings.html