shit-happens chapter :P

levels/shit-happens/bad-commit

@@ -0,0 +1,30 @@
+title = Undo a bad commit
+cards = reset commit-a
+
+[description]
+
+Oh no, we made a bad commit! How can we undo making the commit, and go back to a point where we can try again?
+
+The answer is using `git reset [commit]`, which does two things:
+
+- It resets the current branch ref to the commit you specify.
+- And it resets the index to that commit.
+
+It does not change your working directory in any way, which means that after that, you can try making the commit you want again.
+
+[setup]
+
+echo "1 2 3 4" > numbers
+git add .
+git commit -m "Initial commit"
+echo "1 2 3 4 5 6 7 8 9 11" > numbers
+git commit -am "More numberrrrrs"
+
+[win]
+
+# In the last main commit, the numbers file contains the numbers from 1 to 10.
+test "$(git show main:numbers)" = "1 2 3 4 5 6 7 8 9 10"
+# The commit message of that commit is "More numbers".
+git log -1 --oneline | grep "More numbers"
+# The commit with the typo is not part of the main branch anymore.
+git log --oneline | grep -v "rrrrr"