Development

Code Style

All contributions to hoomd-rs must follow the established code style:

• All hoomd-rs code should be Idiomatic Rust.
• Follow standard API guidelines when implementing new types and traits.
• Spell check your documentation comments AND CODE!
• Name crates, types, traits, fields, methods, and variables with complete words, even for internal names that are not exposed in the public API. Additionally, the chosen word(s) should match those in the most common usage, such as defined in a textbook.

Tools

prek

Run

prek run --all-files

to perform a number of style checks and fixes.

Code formatting

Run

cargo +nightly-2025-09-17 fmt

to automatically format the code. Use the shown Rust nightly version to obtain the same results as the CI checks.

Code Linting

Run

cargo clippy --all-targets --all-features

to ensure that the code follows established best practices.

Spell Checking

Use codebook to check for spelling errors in arguments, variable names, comments, etc… hoomd-rs includes a codebook dictionary file exempting words commonly used throughout the repository.

Build the documentation

mdBook

This documentation is built with mdBook using the following plugins:

• mdbook-alerts
• mdbook-katex

Install these with Cargo:

$ cargo install mdbook mdbook-alerts mdbook-katex

To preview the documentation locally:

$ cd doc
$ mdbook serve --open

rustdoc

To build the API documentation from source, execute:

./build_api_documentation.sh

Open target/doc/hoomd-vector/index.html in your web browser to view the documentation.

WASM

This documentation contains example scripts built for WASM. To build these, you need to install the following tools:

• The wasm Rust target:

  $ rustup target install wasm32-unknown-unknown
  

• wasm-bindgen and wasm-server-runner

  $ cargo install wasm-bindgen-cli wasm-server-runner
  

• wasm-opt. Install with micromamba:

  $ micromamba install binaryen
  

  or by another method of your choice.

For more information, see the WASM chapter in the bevy cheat book.

To add a new web example to this documentation:

• Add the .rs code in the appropriate subdirectory under examples/.
• Add the example target in examples/Cargo.toml, including the metadata section.
• Add .md text in the appropriate subdirectory under doc and list it in SUMMARY.md.

In all cases, see the existing examples for the needed syntax.

To build and test an individual example with WASM (requires wasm-server-runner), run:

$ cargo run --features bevy --target wasm32-unknown-unknown --example {example}

and open the printed http://localhost URL in your browser.

To build all the interactive examples, run:

$ cargo run -p build-wasm-doc-examples

It will build the examples listed in the package metadata in examples/Cargo.toml and place them in doc/src. You can view the interactive example scripts with mdbook serve and navigating to the http://localhost URL. Due to browser security protocols, the examples will not run if you open via the file:// URL.

Caution

DO NOT COMMIT the generated .wasm or .js files to the repository. These will be compiled by CI when needed.

Tip

You can locally test how an example will appear with:

import init from './{example-name}.js'

Important

The import line must be

import init from 'https://glotzerlab.github.io/hoomd-rs/{example-directory}/{example-name}.js'

to appear in the published documentation.

Release Process

To make a new release:

• Run ./diff_public_api.sh (which uses cargo-public-api) to help determine whether this should be a patch, minor, or major release.
  • patch release: no changes at all.
  • minor release: Only added changes (including new crates).
  • major release: Often needed when APIs are changed and removed, though it is very complicated. Our user base is small enough that conservatively making a major release is fine when there is any doubt.
• Make a new release-{X.Y.Z} branch (where {X.Y.Z} is the new version).

On that branch, take the following steps (committing after each step when needed):

• Run prek autoupdate --freeze.
• Check for new or duplicate contributors since the last release:

  comm -13 (git log $(git describe --tags --abbrev=0) --format="%aN <%aE>" | sort | uniq | psub) (git log --format="%aN <%aE>" | sort | uniq | psub)
  

  Add entries to .mailmap to remove duplicates.
• Review release-notes.md and revise if needed.
• Add highlights to release notes (if needed).
• Run ./check_links.sh and fix any broken links. If README.md has changed, this command will copy it to all the crates. Commit the updated README files.
• Run bump-my-version bump {type}. Set {type} to patch, minor, or major.
• Run cargo check
• Run cargo update
• Run cargo bundle-licenses --format yaml --output THIRDPARTY.yaml
• Push the branch and open a pull request.
• Check that readthedocs builds the docs correctly in the pull request checks.
• Merge the pull request after all tests pass.
• Make a new tag on the trunk branch:

  git switch trunk
  git pull
  git tag -a {X.Y.Z}
  git push origin --tags
  

Important

Make sure to exclude v from the tag name!

• Add a blank release notes entry for the next release:

  ## Next release
  
  *Added:*
  
  *Changed:*
  
  *Deprecated:*
  
  *Removed:*
  
  *Fixed:*
  

Note

Paste Next release exactly as shown. bump-my-version will replace that string with the version number and date of the next release.

GitHub Actions will trigger on the tag and upload the release to crates.io and create a GitHub release.

• Check that the GitHub release posted correctly.
• Check that all crates.io uploads succeeded.