Documentation Tests

Rust has built-in support for documentation tests:

  1. #![allow(unused)]
  2. fn main() {
  3. /// Shortens a string to the given length.
  4. ///
  5. ///

/// use playground::shorten_string; /// assert_eq!(shorten_string(“Hello World”, 5), “Hello”); /// assert_eq!(shorten_string(“Hello World”, 20), “Hello World”); /// pub fn shorten_string(s: &str, length: usize) -> &str { &s[..std::cmp::min(length, s.len())] } }

  • Code blocks in /// comments are automatically seen as Rust code.
  • The code will be compiled and executed as part of cargo test.
  • Test the above code on the Rust Playground.