git: undo all working dir changes including new files

git reset --hard # removes staged and working directory changes

## !! be very careful with these !!
## you may end up deleting what you don't want to
## read comments and manual.
git clean -f -d # remove untracked
git clean -f -x -d # CAUTION: as above but removes ignored files like config.
git clean -fxd :/ # CAUTION: as above, but cleans untracked and ignored files through the entire repo (without :/, the operation affects only the current directory)

To see what will be deleted before-hand, without actually deleting it, use the -n flag (this is basically a test-run). When you are ready to actually delete, then remove the -n flag:

git clean -nfd

Have a look at the git clean command.

git-clean - Remove untracked files from the working tree

Cleans the working tree by recursively removing files that are not under version control, starting from the current directory.

Normally, only files unknown to git are removed, but if the -x option is specified, ignored files are also removed. This can, for example, be useful to remove all build products.

git clean -i will first show you the items to be deleted and proceed after your confirmation. I find this useful when dealing with important files that should not be deleted accidentally.

See git help clean for more information, including some other useful options.

If you want to discard all changes, you can use any of the valid options in an alias in .gitconfig. For instance:

[alias]
    discard = "!f() { git add . && git stash && git stash drop stash@{0}; }; f"

Usage: git discard

This is probably a noob answer, but: I use TortoiseGit for windows and it has a nice feature called REVERT. So what you do to revert your local nonstaged nonpushed changes is:

1. bring up a context menu for the needed folder and select revert, it shows a revert popup where you can select changed files to revert/recover.
2. If you also want to delete added files(that are not in git yet) click commit (from same context menu) it brings up the Commit popup and shows you the added files, then right click each of them and choose delete. But dont press Commit btn in this popup, as you dont wanna commit, but only see added files and delete them from here.