Cargo Test

Rust treats testing as a first-class citizen. cargo test runs unit tests (in the same file), integration tests (in tests/), and uniquely, Documentation Tests (code blocks in your doc comments).

When to Use

• Rust Projects: The standard.
• Library Design: Doc tests ensure your examples in README/Docs actually compile and work.

Quick Start

// lib.rs
pub fn add(a: i32, b: i32) -> i32 {
    a + b
}