Appendix F - Useful Development Tools

In this appendix, we talk about some useful development tools that the Cairo project provides. We’ll look at automatic formatting, quick ways to apply warning fixes, a linter, and integrating with IDEs.

Automatic Formatting with scarb fmt

Scarb projects can be formatted using the scarb fmt command. If you're using the Cairo binaries directly, you can run cairo-format instead. Many collaborative projects use scarb fmt to prevent arguments about which style to use when writing Cairo: everyone formats their code using the tool.

To format any Cairo project, enter the following inside the project directory:

scarb fmt

For things you do not want scarb fmt to mangle, use #[cairofmt::skip]:

#[cairofmt::skip]
let table: Array<ByteArray> = array![
    "oxo",
    "xox",
    "oxo",
];

IDE Integration Using cairo-language-server

To help IDE integration, the Cairo community recommends using the cairo-language-server. This tool is a set of compiler-centric utilities that speaks the Language Server Protocol, which is a specification for IDEs and programming languages to communicate with each other. Different clients can use cairo-language-server, such as the Cairo extension for Visual Studio Code.

Visit the vscode-cairo page to install it on VSCode. You will get abilities such as autocompletion, jump to definition, and inline errors.

Note: If you have Scarb installed, it should work out of the box with the Cairo VSCode extension, without a manual installation of the language server.