Fish shell: how to exit on error (bash set -e)

On bash you can use set -e inside a script in order to exit on error:

set -ecd unexisting-folderecho "this line will not be printed"

But on fish shell set -e is used to erase variables:

set FOO barset -e FOOecho {$FOO} # prints newline

What is the equivalent of Bash set -e on Fish?