Add "view file before commit/PR"

When viewing a commit page, GitHub provides a link to view each file. The link points to the file at the current commit. Example.

However, sometimes we want to view the version of a file before the commit was made.

For the longest time I have been doing this manually, by clicking “view file” and then editing the URL to add a ^ at the end of the commit (to reference the parent commit).

It would be very useful if this was added as a link in the menu, so we don’t have to resort to hacking the URL like this.

This would also be useful in PRs, where GitHub similarly shows a “view file” link for each file in the diff. Sometimes we want to view the version of a file before all of the commits in this PR.

[fregante]

This is possible:

Made by:

1. Wrap the existing .dropdown-item link into .d-flex
2. Add identical link but use icon instead of text
3. width: min-content; padding-left: 8px

<div class="d-flex">
  {previousLink}
  <a {… previousLink attrs} style="padding-left: 8px !important;width: min-content;">
    <GitHistoryIcon/>
  </a>
</div>

This should be applied to regular commits as well.

If a file is deleted by the current commit, the “View file” already points to the old commit, so in that case perhaps we should add the icon inside the existing link; this would indicate that the link points to the old commit.

[OliverJAsh]

On the base branch/commit I think? (The existing “view file” points to the head branch/commit.)