Top course of cedar shingle on a lean-to roof
Your roof edge may have different details, but the concept is the same - drip edge is required to prevent water damages.

Drip edges are metal sheets, usually shaped like an “L,” installed at the edge of the roof. Also called drip edge flashing or D-metal, they serve a vital function by directing water away from the fascia and into the gutter. Without a drip edge, water may end up beneath the shingles and may cause damage to various parts of the home. Though your home may not have originally had a drip edge installed, drip edges are now required by most building codes across North America to protect homes from damage.
https://www.iko.com/na/pro/building-professional-tools/learn-about-roofing/guide-to-drip-edges-for-shingle-roofs/
For the ridge: