Working on an Existing Project

Foundry makes developing with existing projects have no overhead.

For this example, we will use PaulRBerg’s foundry-template.

First, clone the project and run forge install inside the project directory.

$ git clone
$ cd foundry-template 
$ forge install
$ bun install # install Solhint, Prettier, and other Node.js deps

We run forge install to install the submodule dependencies that are in the project.

To build, use forge build:

$ forge build
Compiling 28 files with Solc 0.8.25
Solc 0.8.25 finished in 1.36s
Compiler run successful!

And to test, use forge test:

$ forge test
No files changed, compilation skipped

Ran 3 tests for test/Foo.t.sol:FooTest
[PASS] testFork_Example() (gas: 3779)
[PASS] testFuzz_Example(uint256) (runs: 1000, μ: 9111, ~: 9111)
[PASS] test_Example() (gas: 11861)
Suite result: ok. 3 passed; 0 failed; 0 skipped; finished in 19.25ms (19.05ms CPU time)

Ran 1 test suite in 20.80ms (19.25ms CPU time): 3 tests passed, 0 failed, 0 skipped (3 total tests)