• jgruber's avatar
    [coverage] Fix invalid coverage block transformation · e42ce200
    jgruber authored
    Before reporting coverage data, we attempt to reduce clutter by
    merging nested and consecutive ranges. Nested ranges are merged, if
    the child range has the same execution count as the parent range.
    Sibling ranges are merged, if one sibling begins where the other ends
    and execution counts are identical.
    
    This allowed an invalid transformation in which a range with an
    execution count of 1 would be merged into the parent change, but the
    sibling range with identical start and end points and a count of 0
    would remain, effectively deleting the covered range.
    
    For example:
    
    {start: 0, end: 10, count: 1},
    {start: 5, end:  8, count: 1},  // It's invalid to remove this.
    {start: 5, end:  8, count: 0}
    
    The fix is to separate the parent and sibling merge passes, and
    removing duplicate ranges in-between.
    
    Bug: chromium:827530
    Change-Id: Ic35eae1d4a106746570ce9cb412ed6710ef6da53
    Reviewed-on: https://chromium-review.googlesource.com/992114Reviewed-by: 's avatarYang Guo <yangguo@chromium.org>
    Commit-Queue: Jakob Gruber <jgruber@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#52352}
    e42ce200
code-coverage-block.js 29.6 KB