Creating A New Rust Crate
This document contains a set of templates and content that I use by convention in many of the Rust projects I’ve worked on. This list functions as a checklist that can be referenced when creating a new Rust crate and associated source repository, ensuring projects have a consistent level of quality and polish. If these conventions are useful to you, feel free to follow or adapt them in your projects.
README.md
Header Section
Every crate repository should have a header with status ‘shields’ for the latest crates.io release, the crate license, and an indicator of the documentation status. Additionally, there should be a ‘quick links’ bar with links to the online API documentation, CHANGELOG.md, and instructions for contributing to the repository.
The screenshot below illustrates what this standard header content looks like:
Status Shields
[](https://crates.io/crates/CRATE-NAME)  [](https://docs.rs/CRATE-NAME)
Quick Links
Variant A (Markdown):
#### [API Documentation](https://docs.rs/CRATE-NAME) | [Changelog](./docs/CHANGELOG.md) | [Contributing](./docs/CONTRIBUTING.md)
Variant B (Markdown, Contributing is anchor link):
#### [API Documentation](https://docs.rs/CRATE-NAME) | [Changelog](./docs/CHANGELOG.md) | [Contributing](#contributing)
Variant C (HTML; works in .md files too):
<h4> <a href="https://docs.rs/CRATE-NAME">API Documentation</a> <span> | </span> <a href="https://github.com/OWNER/REPO/blob/master/docs/CHANGELOG.md">Changelog</a> <span> | </span> <a href="https://github.com/OWNER/REPO/blob/master/docs/CONTRIBUTING.md">Contributing</a> </h4>
License Section
Note: This content assumes that you have added the LICENSE-APACHE and LICENSE-MIT files to the repository.
## License Licensed under either of * Apache License, Version 2.0 ([LICENSE-APACHE](./LICENSE-APACHE) or <http://www.apache.org/licenses/LICENSE-2.0>) * MIT license ([LICENSE-MIT](./LICENSE-MIT) or <http://opensource.org/licenses/MIT>) at your option.
Contributing Section
## Contributing Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions. <!-- If applicable: --> <!-- See [CONTRIBUTING.md](./docs/CONTRIBUTING.md) for more information. --> <!-- See [**Development.md**](./docs/Development.md) for instructions on how to perform common development tasks when contributing to this project. --> <!-- See [*Maintenance.md*](./docs/Maintenance.md) for instructions on how to maintain this project. -->
Test README.md examples
It is common for Rust repository README.md files to include bits of example code to give potential users a taste of what the library has to offer. However, one disadvantage of putting examples in README.md files is that they are not automatically tested like code examples in Rust documentation comments. This makes it easy for code examples in README.md to get out of date.
Placing the following code in your crate’s lib.rs file will cause code examples in README.md to get tested just like normal documentation examples, ensuring they are always up-to-date:
// Ensure that doc tests in the README.md file get run. #[doc(hidden)] mod test_readme { #![doc = include_str!("../README.md")] }
Project Documentation
docs/Development.md
Template for Development.md:
# Development This document contains information useful to anyone wishing to contribute to the development of this project. ## Quick Command Reference **Build the library:** ```shell $ cargo build ``` **Run the tests:** ```shell $ cargo test ```
docs/Maintenance.md
Template for Maintenance.md:
# Maintenance This document describes steps required to maintain the [[CRATE-NAME]] project. This document is informational and intended for the maintainer of this project; users of this project do not need to read this document.
docs/CHANGELOG.md
This document should follow the Keep a Changelog format.
# Changelog All notable changes to this project will be documented in this file. The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/), and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html). ## [Unreleased] ## [0.0.2] - YYYY-MM-DD ### Added - Added something ([#2]) ### Changed - Fixed something ([#3]) ## [0.0.1] - YYYY-MM-DD Initial release. ### Added - Added all initial functionality ([#1]) <!-- v0.0.1 --> [#1]: https://github.com/OWNER/REPO/pull/1 <!-- v0.0.2 --> [#2]: https://github.com/OWNER/REPO/pull/2 [#3]: https://github.com/OWNER/REPO/pull/3 <!-- This needs to be updated for each tagged release. --> [Unreleased]: https://github.com/OWNER/REPO/compare/v0.0.2...HEAD [0.0.2]: https://github.com/OWNER/REPO/compare/v0.0.1...v0.0.2 [0.0.1]: https://github.com/OWNER/REPO/releases/tag/v0.0.1
I’ve extended the Keep a Changelog format with the basic convention that each change should list the pull request associated with it, if possible.
One subtle aspect of this structure is that the [#X] pull-request list grows downwards, while the [X.X.X] reference links list grows upwards, so that both lists grow to meet at the [Unreleased] reference link. This limits the scrolling that is required to add new links when updating CHANGELOG.md, and generally means that all the links that need to be updated will fit on the screen at once.
Scrolling is a context switch, so not having to scroll as much reduces the likelihood of mistakes when updating links.
Cargo.toml
A sample Cargo.toml:
[package] name = "TheCrate" version = "X.X.X" authors = ["Connor Gray <code@connorgray.com>"] edition = "2021" license = "MIT OR Apache-2.0" readme = "README.md" repository = "https://github.com/OWNER/REPO" description = "Efficient and ergonomic XXXXX" keywords = ["wolfram", "wolfram-language", "mathematica", "expression"] categories = ["XXXX"]
rustfmt.toml
My standard rustfmt.toml content:
max_width = 80 match_block_trailing_comma = true blank_lines_upper_bound = 2 merge_derives = false # Allows separating std derives from third-party crate derives overflow_delimited_expr = true
Adding License Files
LICENSE-MIT content
MIT License Copyright (c) 2022 [Connor Gray | Wolfram Research Inc.] Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
LICENSE-APACHE content
The Apache license does not have an embedded copyright year or copyright holder name, so no modification to the license text is required.
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