| ## Developing the Library’s Functionality with Test-Driven Development | |
| The 2018 edition of the book is no longer distributed with Rust's documentation. | |
| If you came here via a link or web search, you may want to check out [the current | |
| version of the book](../ch12-04-testing-the-librarys-functionality.html) instead. | |
| If you have an internet connection, you can [find a copy distributed with | |
| Rust | |
| 1.30](https://doc.rust-lang.org/1.30.0/book/2018-edition/ch12-04-testing-the-librarys-functionality.html). |