Quite often when reviewing code I will make a few comments on the diff.
Some of these comments are important and block me from clicking 'Ship It'.
Some of the comments are recommendations or suggestions.
At the moment I have to follow up these diff comments with a review
comment, pointing out which issues I expect to be fixed and which I don't.
It would be nice when adding diff comments if the author could set this as
a 'blocking' comment and when someone is reviewing the comments the ones
set as 'blocker' are highlighted to indicate their importance (surround the
comment with a red box for example).
Obviously I could add an additional line to the diff comment saying I
expect this to be fixed, but an extra highlight would make this more
obvious to the review creator.
