The most convenient way I found is:
- Open PR conversation
- Find the last commit that have already been reviewed and click its hash link, your URL will look like https://github.com/airbnb/javascript/pull/188/commits/2b6c524e6984f300f6c6e08e57c8dbab9497e798
- Change
commits
tofiles
and add..HEAD
to the end of URL such as https://github.com/airbnb/javascript/pull/188/files/2b6c524e6984f300f6c6e08e57c8dbab9497e798..HEAD
You’ll see commits range you want to review in context of the PR.
P.S. Now GitHub provides functionality to view “Changes since your previous code review” but sometimes it is useful to select changes manually