What is cargo-runner?

Cargo Runner is a VS Code extension that makes working with Rust code faster and more convenient. It adds clickable buttons directly above your functions, structs, and modules so you can run or debug them without typing commands in a terminal. If you write Rust in VS Code, this tool saves you from constantly switching contexts to test or execute a specific piece of code. The extension works alongside rust-analyzer, the standard Rust language support tool for VS Code. When you open a Rust file and place your cursor inside a function or test, Cargo Runner displays small "Run," "Debug," or "Run Test" buttons, called CodeLens buttons, right above that code block. You can click those buttons or use a keyboard shortcut to instantly execute whatever your cursor is on. It requires both rust-analyzer and a debugger extension called codelldb to function. Where the extension really shines is its configuration system. Rust projects often need specific settings turned on or off, like enabling certain features, targeting a specific platform, or setting environment variables. Cargo Runner lets you change these settings on the fly using a quick command palette shortcut. You can type things like "--features my-feature" to enable options, set environment variables, or even switch between stable and nightly Rust versions, all without digging through configuration files. A reset command lets you undo changes, and an append mode lets you add to existing settings rather than replacing them. This tool is built for Rust developers who spend their days in VS Code and want to reduce friction. If you are working on a web server and need to quickly run one endpoint with a database URL, or you are building a WebAssembly module and need to switch your build target, you can do it in a couple of keystrokes. It also supports cargo-nextest, a popular alternative test runner, for those who need faster test execution.