How to ignore some statements in Javascript code coverage when using lcov and istanbul?

How is it possible to make sonarqube take into account directives found in code comments ? There is a page on istanbul describing how to ignore some branches using comments like this

/* istanbul ignore if */ if (hardToReproduceError)) { return callback(hardToReproduceError); }

(see http://ift.tt/1KOO4H6)

It works well into HTML reports generated by istanbul but it does not work with Sonarqube.

via Chebli Mohamed