I have a pipeline with a very simple set of instructions, as follows:

dir('front-end') {
   sh 'npm install'
   sh 'ionic android build'
}

But if I run it like the code above, it fails mid-compilation. I have already also tried like this:

sh 'cd front-end/'
sh 'npm install'
sh 'ionic android build'

Also fails (different error though).

The only way I got it working was to put it all together using triple-quotes, like this:

sh '''\
cd front-end/
npm install
ionic android build
'''

Why is that?