Install toncli and TON binaries, then run:
toncli run_tests
.
├── build
│ ├── contract.fif - auto build of func/code.fc
│ └──contract_tests.fif - auto build of tests/example.fc
├── func
│ └── code.fc - code of first contest task
├── project.yaml - project structure for toncli
├── README.md
└── tests
└── example.fc - tests code
P.S. If you really interest in how tests works - check out here