First Steps with Foundry

This section introduces the forge command-line tool. We will walk through creating a new project, compiling it, and running tests.

To start a new project with Foundry, use the forge init command:

$ forge init hello_foundry

Now, let’s explore the structure that forge has generated for us:

$ cd hello_foundry
$ tree . -d -L 1
.
├── lib
├── script
├── src
└── test

4 directories

You can compile the project using forge build:

$ forge build
Compiling 27 files with Solc 0.8.19
Solc 0.8.19 finished in 1.12s
Compiler run successful!

To run the tests, use the forge test command:

$ forge test
No files changed, compilation skipped

Ran 2 tests for test/Counter.t.sol:CounterTest
[PASS] testFuzz_SetNumber(uint256) (runs: 256, μ: 31210, ~: 31288)
[PASS] test_Increment() (gas: 31303)
Suite result: ok. 2 passed; 0 failed; 0 skipped; finished in 7.90ms (7.55ms CPU time)

Ran 1 test suite in 8.87ms (7.90ms CPU time): 2 tests passed, 0 failed, 0 skipped (2 total tests)

💡 Tip

You can always view detailed help for any command or subcommand by appending --help to it.

For visual learners, be sure to check out these beginner tutorials.

Foundry Book

First Steps with Foundry