Problem:

As a relatively fresh user of Git I've several times accidentally committed all changes instead of just one file.
This is very frustrating because every time I have to make sure that I correctly undo the changes manually, and I get freaked out because I'm scared I'll lose my work if I do it incorrectly (e.g. deleting the commit without restoring the files).

Solutions

• It would be very useful to have an "Undo Commit" button so that I can easily fix my mistake.
• Ctrl+Z could also be an option, but if the keyboard focus is in the text editor instead of the Git Changes window, that could make things even worse by changing a file.
• An alternative is an option to only allow commits of staged files. That way I wouldn't forget to do the staging. Since it would be a necessary step it would impossible to "accidentally" stage all files instead of just some.

The state after the "Undo Commit" should be the state before clicking the "Commit" button, preferably with the written commit message.
The Undo Commit button/command would run git reset HEAD~1 with the correct option (probably --soft, but I may be mistaken).

Alternatives

From my mistakes and subsequent web-searches, I know git reset --soft HEAD~1 basically undoes the commit, but I have to use the command line git tools to do that, and I have to look up on the web the correct commands so that I don't accidentally destroy all the changes I've made - I suspect git reset --hard HEAD~1 would to that, but I'm not sure.
It also leaves all changes in a staged state, so unstaging them is another step that could lead to mistakes.
And it also doesn't preserve the commit message.

There are probably good external tools out there, and I've even considered writing my own tool for fixing my common mistakes.
But it would be much better if Visual Studio's Git tools were enough. I mean, it's almost 2021, and practically all software has an undo command. 😉