This repo provides an example of how a view calls to confidential contracts on Oasis Sapphire can be used to create rollups and state channels.
Using the @oasis-protocol/sapphire-contracts library The contracts generates their own secrets which are used to either encrypt state that only they can access, or to sign state which can be independently verified.
While @oasis-protocol/sapphire-hardhat package makes testing easy with Hardhat, you also need to run a local sapphire-dev instance which supports the necessary EVM precompiles.
For your convenience there is a Makefile which uses Docker to keep everything neatly contained:
make sapphire-dev & # This will take a few minutes
make pnpm-install
make hardhat-compile
make hardhat-test