This is a material node graph that is set up for you to have lots of control to get a NPR or toon look.
Examples and explanation found here. https://youtu.be/gprT-3Byc2Y
thank you for the shader, i've used it in my work https://www.blendswap.com/blend/25832
I just watched this video the other day on Youtube while looking for 2.8 content..great stuff.