1603383 - Code coverage line information is broken

Status: NEW

(Testing :: Code Coverage, defect, P3)

Description

[Simon Giesecke [:sg] [he/him]]

On https://coverage.moz.tools/#revision=latest&path=dom%2FindexedDB%2FActorsParent.cpp&view=file&suite=all, the line information of coverage data cannot be correct. E.g. lines 18442 and 18443 are shown as uncovered, but these are comment lines. The problems seem to start around line 11353 (which is an empty line between two functions reported as covered).

Comment 1

[Marco Castelluccio [:marco]]

I've never seen this before, and it is no longer happening on that specific file. Maybe it was some kind of intermittent issue.
Simon, could you take note of the revision if you see this again?

Comment 2

[Simon Giesecke [:sg] [he/him]]

I have seen this again on various files, but a rather simple one is https://coverage.moz.tools/#revision=latest&path=mfbt%2FReverseIterator.h&suite=all&view=file

I am not sure how to get a link to the current revision (I can enter some instead of latest, but I don't know which one that would be).

Comment 3

[Simon Giesecke [:sg] [he/him]]

I have the impression that there sometimes is a mismatch between the source revision from whose build the coverage was obtained and the source revision displayed when the default of latest is used. Is that possible?

Comment 4

[Simon Giesecke [:sg] [he/him]]

I gave this another try now, and it's also broken for https://coverage.moz.tools/#revision=latest&path=mfbt%2FResult.h&view=file&suite=cppunittest, almost from the beginning of the file. It's pretty useless in this state. What's even worse is that for other files, it might not even be obvious that the line association is wrong.

Comment 5

[Simon Giesecke [:sg] [he/him]]

Today, I tried to inspect the code coverage of nsURLHelper.cpp, which was changed last week. The current coverage report at https://coverage.moz.tools/#revision=latest&path=netwerk%2Fbase%2FnsURLHelper.cpp&view=file shows the newly added lines, but no coverage information for those, so there's clearly a mismatch between the coverage information and the source revision shown. This also explains the line mismatches I experienced earlier. The coverage view is useless for recently changed files in the current form.

Comment 6

[Marco Castelluccio [:marco]]

Sorry for the delay, I never seem to get to this...

(In reply to Simon Giesecke [:sg] [he/him] from comment #3)

I have the impression that there sometimes is a mismatch between the source revision from whose build the coverage was obtained and the source revision displayed when the default of latest is used. Is that possible?

This is indeed the case: https://github.com/mozilla/code-coverage/issues/525.