Extends paulx' Solana escrow tutorial with integration tests to check correctness of the code.
- Install Rust from https://rustup.rs/
- Install Solana v1.7 or later from https://docs.solana.com/cli/install-solana-cli-tools#use-solanas-install-tool
$ cargo build-bpf
# this runs the integration test
$ cargo test-bpf