Add this suggestion to a batch that can be applied as a single commit.
  This suggestion is invalid because no changes were made to the code.
  Suggestions cannot be applied while the pull request is closed.
  Suggestions cannot be applied while viewing a subset of changes.
  Only one suggestion per line can be applied in a batch.
  Add this suggestion to a batch that can be applied as a single commit.
  Applying suggestions on deleted lines is not supported.
  You must change the existing code in this line in order to create a valid suggestion.
  Outdated suggestions cannot be applied.
  This suggestion has been applied or marked resolved.
  Suggestions cannot be applied from pending reviews.
  Suggestions cannot be applied on multi-line comments.
  Suggestions cannot be applied while the pull request is queued to merge.
  Suggestion cannot be applied right now. Please check back later.
  
    
  
    
Partially fixes #2549.
It fixes only
instanceof Errorand does not affectinstanceof AnySubClassOfErrornor any otherinstanceofusage. Because it is so specific, I don't think it is suitable for merging. #5995 would certainly be a better fix, if it worked.Comparing my fix and #5995, I think the problem might be that errors are somehow mishandled in
jestitself, which results in issues withinstanceof SubClassOfErrorchecks withinjest. Once those are fixed, #5995 should just work. Does it make sense?cc @SimenB