It’s basically exactly what you’re asking, here’s the page that describes it.
It doesn’t taste like coffee in the least. It tastes more like tea (but there is tea in it so it’s probably that). However, it does kick up an allergic reaction in my throat (Oral Allergy Syndrome) the same way coffee does, so I can’t drink it.
I tasted a fresh-off-the-tree coffee cherry while touring a coffee farm in Hawaii. Imagine soaking a peach in cold coffee overnight, then eating it. Nasty.
It’s the most common way coffee is consumed in Yemen. The Yemeni people export the profitable seeds and keep the husk/fruit/cherry/pericarp. They dry it and with it make a sort of tea, called qishr, which means ‘husk’. I once found it in a health food store sold as an herbal tea.