This repo contains a minimal circuit in the circuit directory, a script to build it and a test to generate a proof and verify it.
The circuit proves that the addition of a + b == c if enforce unequal 0. This is an unsafe pattern since you cannot rely that the public input c is actually the sum of a + b since the enforce input is a private input. Also this highlights the difficulty of implementing conditional logic in circuits. All paths need to be defined at compile time of the circuit. Enforce is a work around this.
npm i
npm run build
npm test